Journal articles on the topic 'External validity bias'
To see the other types of publications on this topic, follow the link: External validity bias.
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 50 journal articles for your research on the topic 'External validity bias.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse journal articles on a wide variety of disciplines and organise your bibliography correctly.
1
Lei, Yang, James C. Bezdek, Simone Romano, Nguyen Xuan Vinh, Jeffrey Chan, and James Bailey. "Ground truth bias in external cluster validity indices." Pattern Recognition 65 (May 2017): 58–70. http://dx.doi.org/10.1016/j.patcog.2016.12.003.
Full text
2
Andrews, Isaiah, and Emily Oster. "A simple approximation for evaluating external validity bias." Economics Letters 178 (May 2019): 58–62. http://dx.doi.org/10.1016/j.econlet.2019.02.020.
Full text
3
Cipriani, Andrea, Marianna Purgato, and Corrado Barbui. "Why internal and external validity of experimental studies are relevant for clinical practice?" Epidemiologia e Psichiatria Sociale 18, no. 2 (June 2009): 101–3. http://dx.doi.org/10.1017/s1121189x00000968.
Full textAbstract:
In randomised controlled trials (RCTs) there are two types of validity: internal validity and external validity. Internal validity refers to the extent to which the observed difference between groups can be correctly attributed to the intervention under investigation. In other words, it is the extent to which the design and conduct of the trial eliminate error. Internal validity might be threatened by two types of errors: systematic error (also called bias) and chance error (also called random error or statistical error) (Keirse & Hanssens, 2000. Systematic error, or bias, may be the consequence of erroneous ways of collecting, analysing and interpreting data. This may produce differences between treatments that are not real, with an overestimation or an underestimation of the true beneficial or harmful effect of an intervention (Juni et al., 2001). In RCTs there are four types of bias: selection bias (when the groups differ in baseline characteristics because of the way participants are selected), performance bias (when the care provided to the trial participants differs systematically between the experimental and control group), detection bias (when there are systematic differences in outcome assessment), and attrition bias (when the loss of participants from the study systematically differs between the experimental and control group). By contrast, chance error, or statistical error, is due to outcome variability that may arise by chance alone. Studies with small sample sizes are more likely to incur in this type of error than studies with large sample sizes. Thus, the risk of random error may be minimised by recruiting sufficiently large samples of patients.
4
Mayeda, Elizabeth Rose, Eleanor Hayes-Larson, and Hailey Banack. "Who’s in and Who’s Out? Selection Bias in Aging Research." Innovation in Aging 4, Supplement_1 (December 1, 2020): 822. http://dx.doi.org/10.1093/geroni/igaa057.2998.
Full textAbstract:
Abstract Selection bias presents a major threat to both internal and external validity in aging research. “Selection bias” refers to sample selection processes that lead to statistical associations in the study sample that are biased estimates of causal effects in the population of interest. These processes can lead to: (1) results that do not generalize to the population of interest (threat to external validity) or (2) biased effect estimates (associations that do not represent causal effects for any population, including the people in the sample; a threat to internal validity). In this presentation, we give an overview of selection bias in aging research. We will describe processes that can give rise to selection bias, highlight why they are particularly pervasive in this field, and present several examples of selection bias in aging research. We end with a brief summary of strategies to prevent and correct for selection bias in aging research.
5
Moore, Randall P., and W. Douglas Robinson. "ARTIFICIAL BIRD NESTS, EXTERNAL VALIDITY, AND BIAS IN ECOLOGICAL FIELD STUDIES." Ecology 85, no. 6 (June 2004): 1562–67. http://dx.doi.org/10.1890/03-0088.
Full text
6
Bell, Stephen H., Robert B. Olsen, Larry L. Orr, and Elizabeth A. Stuart. "Estimates of External Validity Bias When Impact Evaluations Select Sites Nonrandomly." Educational Evaluation and Policy Analysis 38, no. 2 (June 2016): 318–35. http://dx.doi.org/10.3102/0162373715617549.
Full text
7
Khorsan, Raheleh, and Cindy Crawford. "External Validity and Model Validity: A Conceptual Approach for Systematic Review Methodology." Evidence-Based Complementary and Alternative Medicine 2014 (2014): 1–12. http://dx.doi.org/10.1155/2014/694804.
Full textAbstract:
Background. Evidence rankings do not consider equally internal (IV), external (EV), and model validity (MV) for clinical studies including complementary and alternative medicine/integrative health care (CAM/IHC) research. This paper describe this model and offers an EV assessment tool (EVAT©) for weighing studies according to EV and MV in addition to IV.Methods. An abbreviated systematic review methodology was employed to search, assemble, and evaluate the literature that has been published on EV/MV criteria. Standard databases were searched for keywords relating to EV, MV, and bias-scoring from inception to Jan 2013. Tools identified and concepts described were pooled to assemble a robust tool for evaluating these quality criteria.Results. This study assembled a streamlined, objective tool to incorporate for the evaluation of quality of EV/MV research that is more sensitive to CAM/IHC research.Conclusion.Improved reporting on EV can help produce and provide information that will help guide policy makers, public health researchers, and other scientists in their selection, development, and improvement in their research-tested intervention. Overall, clinical studies with high EV have the potential to provide the most useful information about “real-world” consequences of health interventions. It is hoped that this novel tool which considers IV, EV, and MV on equal footing will better guide clinical decision making.
8
Huddleston, R. Joseph. "Think Ahead: Cost Discounting and External Validity in Foreign Policy Survey Experiments." Journal of Experimental Political Science 6, no. 02 (November 19, 2018): 108–19. http://dx.doi.org/10.1017/xps.2018.22.
Full textAbstract:
AbstractThis paper considers the implications of construal level theory in the context of survey experiments probing foreign policy opinion formation. Psychology research demonstrates that people discount the long-term consequences of decisions, thinking about distal or hypothetical events more abstractly than immediate scenarios. I argue that this tendency introduces a bias into survey experiments on foreign policy opinion. Respondents reasoning about an impending military engagement are likelier to consider its costs than are those reasoning in the abstract hypothetical environment. I provide evidence of this bias by replicating a common audience costs experimental design and introducing a prompt to consider casualties. I find that priming respondents to articulate their expectations about casualties in a foreign intervention reduces support and dampens the experimental effect, thereby cutting the estimated absolute audience cost substantially. This result suggests a gap between how survey respondents approach hypothetical and real situations of military intervention.
9
He, Yuanda, Qi Zhou, Sheng Lin, and Liping Zhao. "Validity Evaluation Method Based on Data Driving for On-Line Monitoring Data of Transformer under DC-Bias." Sensors 20, no. 15 (August 3, 2020): 4321. http://dx.doi.org/10.3390/s20154321.
Full textAbstract:
The DC-bias monitoring device of a transformer is easily affected by external noise interference, equipment aging, and communication failure, which makes it difficult to guarantee the validity of monitoring data and causes great problems for future data analysis. For this reason, this paper proposes a validity evaluation method based on data driving for the on-line monitoring data of a transformer under DC-bias. First, the variation rule and threshold range of monitoring data for neutral point DC, vibration, and noise of the transformer under different working conditions are obtained through statistical analysis. Then, the data validity criterion of DC bias monitoring data is proposed to achieve a comprehensive evaluation of data validity based on data threshold, continuity, impact, and correlation. In addition, case studies are carried out on the real measured data of the DC bias magnetic monitoring system of a regional power grid by using this evaluation method. The results show that the proposed method can systematically and comprehensively evaluate the validity of the DC bias monitoring data and can judge whether the monitoring device fails to a certain extent.
10
Larrabee, Glenn J. "Performance Validity and Symptom Validity in Neuropsychological Assessment." Journal of the International Neuropsychological Society 18, no. 4 (May 8, 2012): 625–30. http://dx.doi.org/10.1017/s1355617712000240.
Full textAbstract:
AbstractFailure to evaluate the validity of an examinee's neuropsychological test performance can alter prediction of external criteria in research investigations, and in the individual case, result in inaccurate conclusions about the degree of impairment resulting from neurological disease or injury. The terms performance validity referring to validity of test performance (PVT), and symptom validity referring to validity of symptom report (SVT), are suggested to replace less descriptive terms such as effort or response bias. Research is reviewed demonstrating strong diagnostic discrimination for PVTs and SVTs, with a particular emphasis on minimizing false positive errors, facilitated by identifying performance patterns or levels of performance that are atypical for bona fide neurologic disorder. It is further shown that false positive errors decrease, with a corresponding increase in the positive probability of malingering, when multiple independent indicators are required for diagnosis. The rigor of PVT and SVT research design is related to a high degree of reproducibility of results, and large effect sizes of d=1.0 or greater, exceeding effect sizes reported for several psychological and medical diagnostic procedures. (JINS, 2012, 18, 1–7)
11
Tugwell, Peter, André Knottnerus, and Leanne Idzerda. "Comparative effectiveness reviews need to pay as much attention to external validity as to internal validity risks of bias." Journal of Clinical Epidemiology 64, no. 11 (November 2011): 1163–65. http://dx.doi.org/10.1016/j.jclinepi.2011.08.005.
Full text
12
Dierckx, Kim, Alain Van Hiel, James D. Johnson, Len Lecci, Barbara Valcke, and Eva Kefilwe Sekwena. "Adaptation and validation of the Johnson-Lecci scale to assess anti-white bias among black UK minority group members." PLOS ONE 17, no. 11 (November 28, 2022): e0277077. http://dx.doi.org/10.1371/journal.pone.0277077.
Full textAbstract:
The present study (total N = 901) set out to construct and validate a culturally sensitive instrument to examine anti-White bias among Black UK minority group members. Our novel measure of anti-White bias–which we called the AWB scale–was based upon the Johnson-Lecci scale (JLS; 2003) a questionnaire designed to measure anti-White attitudes among Black Americans. Studies 1 and 2 provided converging evidence for the AWB’s four-factor dimensionality, its structural characteristics, its temporal stability and its external validity in Black UK samples, attesting to the consistency of minorities’ experience of anti-majority bias in two very different societal contexts. Moreover, Study 3 evidenced our measure’s utility for understanding reactions to various relevant contemporary societal events. Theoretical contributions to the literature on intergroup bias are delineated and compared with majority-to-minority prejudice.
13
Zhang, Fengying, Yan Liu, Weijie Ma, Shengming Zhao, Jin Chen, and Zhichun Gu. "Nonlinear Machine Learning in Warfarin Dose Prediction: Insights from Contemporary Modelling Studies." Journal of Personalized Medicine 12, no. 5 (April 29, 2022): 717. http://dx.doi.org/10.3390/jpm12050717.
Full textAbstract:
Objective: This study aimed to systematically assess the characteristics and risk of bias of previous studies that have investigated nonlinear machine learning algorithms for warfarin dose prediction. Methods: We systematically searched PubMed, Embase, Cochrane Library, Chinese National Knowledge Infrastructure (CNKI), China Biology Medicine (CBM), China Science and Technology Journal Database (VIP), and Wanfang Database up to March 2022. We assessed the general characteristics of the included studies with respect to the participants, predictors, model development, and model evaluation. The methodological quality of the studies was determined, and the risk of bias was evaluated using the Prediction model Risk of Bias Assessment Tool (PROBAST). Results: From a total of 8996 studies, 23 were assessed in this study, of which 23 (100%) were retrospective, and 11 studies focused on the Asian population. The most common demographic and clinical predictors were age (21/23, 91%), weight (17/23, 74%), height (12/23, 52%), and amiodarone combination (11/23, 48%), while CYP2C9 (14/23, 61%), VKORC1 (14/23, 61%), and CYP4F2 (5/23, 22%) were the most common genetic predictors. Of the included studies, the MAE ranged from 1.47 to 10.86 mg/week in model development studies, from 2.42 to 5.18 mg/week in model development with external validation (same data) studies, from 12.07 to 17.59 mg/week in model development with external validation (another data) studies, and from 4.40 to 4.84 mg/week in model external validation studies. All studies were evaluated as having a high risk of bias. Factors contributing to the risk of bias include inappropriate exclusion of participants (10/23, 43%), small sample size (15/23, 65%), poor handling of missing data (20/23, 87%), and incorrect method of selecting predictors (8/23, 35%). Conclusions: Most studies on nonlinear-machine-learning-based warfarin prediction models show poor methodological quality and have a high risk of bias. The analysis domain is the major contributor to the overall high risk of bias. External validity and model reproducibility are lacking in most studies. Future studies should focus on external validity, diminish risk of bias, and enhance real-world clinical relevance.
14
Wing, Coady, and Ricardo A. Bello-Gomez. "Regression Discontinuity and Beyond." American Journal of Evaluation 39, no. 1 (February 12, 2018): 91–108. http://dx.doi.org/10.1177/1098214017736155.
Full textAbstract:
Treatment effect estimates from a regression discontinuity design (RDD) have high internal validity. However, the arguments that support the design apply to a subpopulation that is narrower and usually different from the population of substantive interest in evaluation research. The disconnect between RDD population and the evaluation population of interest suggests that RDD evaluations lack external validity. New methodological research offer strategies for studying and sometimes improving external validity in RDDs. This article examines four techniques: comparative RDD, covariate matching RDD, treatment effect derivatives, and statistical tests for local selection bias. The goal of the article is to help evaluators understand the logic, assumptions, data requirements, and reach of the new methods.
15
Ulbrich-Zürni, Susanne, Petter Viksveen, E. Roberts, Elizabeth Baitson, Lynn Legg, Jonathan Davidson, and Robert Mathie. "Systematic Review and Meta-Analysis of Randomised, Other-than-Placebo Controlled, Trials of Individualised Homeopathic Treatment." Homeopathy 107, no. 04 (August 18, 2018): 229–43. http://dx.doi.org/10.1055/s-0038-1667129.
Full textAbstract:
Background This study focuses on randomised controlled trials (RCTs) of individualised homeopathic treatment (IHT) in which the control (comparator) group was other than placebo (OTP). Aims To determine the comparative effectiveness of IHT on health-related outcomes in adults and children for any clinical condition that has been the subject of at least one OTP-controlled trial. For each study, to assess the risk of bias and to determine whether its study attitude was predominantly ‘pragmatic’ or ‘explanatory’. Methods Systematic review. For each eligible trial, published in the peer-reviewed literature up to the end of 2015, we assessed its risk of bias (internal validity) using the seven-domain Cochrane tool, and its relative pragmatic or explanatory attitude (external validity) using the 10-domain PRECIS tool. We grouped RCTs by whether they examined IHT as an alternative treatment (study design Ia), adjunctively with another intervention (design Ib), or compared with a no-intervention group (design II). For each RCT, we identified a ‘main outcome measure’ to use in meta-analysis: ‘relative effect size’ was reported as odds ratio (OR; values >1 favouring homeopathy) or standardised mean difference (SMD; values < 0 favouring homeopathy). Results Eleven RCTs, representing 11 different medical conditions, were eligible for study. Five of the RCTs (four of which in design Ib) were judged to have pragmatic study attitude, two were explanatory, and four were equally pragmatic and explanatory. Ten trials were rated ‘high risk of bias’ overall: one of these, a pragmatic study with design Ib, had high risk of bias solely regarding participant blinding (a bias that is intrinsic to such trials); the other trial was rated ‘uncertain risk of bias’ overall. Eight trials had data that were extractable for analysis: for four heterogeneous trials with design Ia, the pooled OR was statistically non-significant; collectively for three clinically heterogeneous trials with design Ib, there was a statistically significant SMD favouring adjunctive IHT; in the remaining trial of design 1a, IHT was non-inferior to fluoxetine in the treatment of depression. Conclusions Due to the low quality, the small number and the heterogeneity of studies, the current data preclude a decisive conclusion about the comparative effectiveness of IHT. Generalisability of findings is limited by the variable external validity identified overall; the most pragmatic study attitude was associated with RCTs of adjunctive IHT. Future OTP-controlled trials in homeopathy should aim, as far as possible, to promote both internal validity and external validity.
16
Masters, Geofferey N. "Anchor Tests, Score Equating and Sex Bias." Australian Journal of Education 32, no. 1 (April 1988): 25–43. http://dx.doi.org/10.1177/000494418803200102.
Full textAbstract:
This paper discusses the use of anchor tests (scaling tests) to bring two or more sets of scores to a common scale. Particular attention is given to the rescaling of school-based assessments against an external test or examination and to potential sources of bias in this procedure. The need for routine validity checks is emphasized, and a latent trait approach to constructing a statistical framework for tests and examination score equating is described and illustrated. Bias caused by rescaling school assessments against an inappropriate anchor test is illustrated using a 1984 attempt to rescale students' assessments in English against the Australian Scholastic Aptitude Test.
17
Lee, Daniel. "Does Implicit Bias Predict Dictator Giving?" Games 9, no. 4 (September 21, 2018): 73. http://dx.doi.org/10.3390/g9040073.
Full textAbstract:
Implicit associations and biases are carried without awareness or conscious direction, yet there is reason to believe they may be influenced by social pressures. In this paper, I study social pressure as a motive to give, as well as giving itself under conditions of implicit bias. In doing so, I pair the Implicit Association Test (IAT), commonplace in other social sciences, with a laboratory dictator game with sorting. I find that despite its popularity, the IAT does not predict dictator giving and social pressure does not explain acts of giving from biased dictators. These results are indicative of the meaningful difference between having an implicit bias and acting on one. As such, results can be thought of as a bound on the external validity of the IAT.
18
Cuthbert, Colleen A., Kathryn King-Shier, Dean Ruether, Dianne M. Tapp, and S. Nicole Culos-Reed. "What is the State of the Science on Physical Activity Interventions for Family Caregivers? A Systematic Review and RE-AIM Evaluation." Journal of Physical Activity and Health 14, no. 7 (July 2017): 578–95. http://dx.doi.org/10.1123/jpah.2016-0280.
Full textAbstract:
Background:Family caregivers are an important health care resource and represent a significant proportion of Canadian and US populations. Family caregivers suffer physical and psychological health problems because of being in the caregiver role. Interventions to support caregiver health, including physical activity (PA), are slow to be investigated and translated into practice.Purpose:To examine the evidence for PA interventions in caregivers and determine factors hampering the uptake of this evidence into practice.Methods:A systematic review and evaluation of internal and external validity using the RE-AIM (Reach, Efficacy/Effectiveness, Adoption, Implementation, and Maintenance) framework was conducted. Randomized controlled trials or pretest/posttest studies of PA interventions were included.Results:Fourteen studies were published between 1997 and 2015. Methodological quality of studies and risk of bias was variable. External validity criteria were often not reported. Mean reporting levels were 1) reach, 53%; 2) efficacy/effectiveness, 73%; 3) adoption, 18%; 4) implementation, 48%; and 5) maintenance, 2%.Conclusions:The lack of reporting of components of internal and external validity hinders the integration of caregiver PA interventions into clinical or community settings. Researchers should focus on standardized outcomes, accepted reporting criteria, and balancing factors of internal and external validity, to advance the state of the science.
19
D'Andrea, Elvira, Lydia Vinals, Elisabetta Patorno, Jessica M. Franklin, Dimitri Bennett, Joan A. Largent, Daniela C. Moga, et al. "How well can we assess the validity of non-randomised studies of medications? A systematic review of assessment tools." BMJ Open 11, no. 3 (March 2021): e043961. http://dx.doi.org/10.1136/bmjopen-2020-043961.
Full textAbstract:
ObjectiveTo determine whether assessment tools for non-randomised studies (NRS) address critical elements that influence the validity of NRS findings for comparative safety and effectiveness of medications.DesignSystematic review and Delphi survey.Data sourcesWe searched PubMed, Embase, Google, bibliographies of reviews and websites of influential organisations from inception to November 2019. In parallel, we conducted a Delphi survey among the International Society for Pharmacoepidemiology Comparative Effectiveness Research Special Interest Group to identify key methodological challenges for NRS of medications. We created a framework consisting of the reported methodological challenges to evaluate the selected NRS tools.Study selectionChecklists or scales assessing NRS.Data extractionTwo reviewers extracted general information and content data related to the prespecified framework.ResultsOf 44 tools reviewed, 48% (n=21) assess multiple NRS designs, while other tools specifically addressed case–control (n=12, 27%) or cohort studies (n=11, 25%) only. Response rate to the Delphi survey was 73% (35 out of 48 content experts), and a consensus was reached in only two rounds. Most tools evaluated methods for selecting study participants (n=43, 98%), although only one addressed selection bias due to depletion of susceptibles (2%). Many tools addressed the measurement of exposure and outcome (n=40, 91%), and measurement and control for confounders (n=40, 91%). Most tools have at least one item/question on design-specific sources of bias (n=40, 91%), but only a few investigate reverse causation (n=8, 18%), detection bias (n=4, 9%), time-related bias (n=3, 7%), lack of new-user design (n=2, 5%) or active comparator design (n=0). Few tools address the appropriateness of statistical analyses (n=15, 34%), methods for assessing internal (n=15, 34%) or external validity (n=11, 25%) and statistical uncertainty in the findings (n=21, 48%). None of the reviewed tools investigated all the methodological domains and subdomains.ConclusionsThe acknowledgement of major design-specific sources of bias (eg, lack of new-user design, lack of active comparator design, time-related bias, depletion of susceptibles, reverse causation) and statistical assessment of internal and external validity is currently not sufficiently addressed in most of the existing tools. These critical elements should be integrated to systematically investigate the validity of NRS on comparative safety and effectiveness of medications.Systematic review protocol and registrationhttps://osf.io/es65q.
20
Berstock, James R., and Michael R. Whitehouse. "How to prepare and manage a systematic review and meta-analysis of clinical studies." EFORT Open Reviews 4, no. 5 (May 2019): 213–20. http://dx.doi.org/10.1302/2058-5241.4.180049.
Full textAbstract:
Use the PICO framework to formulate a specific clinical question. Formulate a search strategy. Prospectively register the review protocol. Execute the literature search. Apply eligibility criteria to exclude irrelevant studies. Extract data and appraise each study for risk of bias and external validity. Provide a narrative review. If appropriate data are available, perform a meta-analysis. Report the review findings in the context of the risk of bias assessment, any sensitivity analyses and the analysis of risk of publication bias. Useful resources include the Cochrane Handbook, PROSPERO, GRADE and PRISMA. Cite this article: EFORT Open Rev 2019;4:213-220. DOI: 10.1302/2058-5241.4.180049
21
Raji, Rahman Olanrewaju. "Testing the Validity of the Triple Deficit Hypothesis for Nigeria." Econometric Research in Finance 4, no. 2 (September 29, 2019): 89–109. http://dx.doi.org/10.33119/erfin.2019.4.2.2.
Full textAbstract:
This paper tests the validity of the triple deficit hypothesis in Nigeria by examining the causal relationship among current account deficit, financial account deficit, and fiscal deficit within a five-variate ARDL framework complemented with GMM framework for the period 2008-2017 using quarterly data. The paper obviates the variable omission bias that characterizes most existing studies. The ARDL-bound testing technique confirms that there is the presence of a long-run bi-causal relationship between current account and financial account deficits in Nigeria. The results based on the model and empirical outputs suggest that authorities of this economy must put in place a fully fiscal and monetary discipline policy that should ensure the drastic curtailment of fiscal deficit and create a conducive environment to attract foreign remittances and foreign investment, which would help to generate healthy external balances. In addition, exchange rate stability can promote the export sector and minimize external imbalances through creating critical surpluses in current accounts, including related comprehensive discipline policies that may be pursued, which enable the external sector, financial and fiscal sectors, and monetary sector to perform without creating adverse imbalances in this economy.
22
Chen, Szu-Wei, Marian Keglovits, Megen Devine, and Susan Stark. "Sociodemographic Differences in Respondent Preferences for Survey Formats: Sampling Bias and Potential Threats to External Validity." Archives of Rehabilitation Research and Clinical Translation 4, no. 1 (March 2022): 100175. http://dx.doi.org/10.1016/j.arrct.2021.100175.
Full text
23
Steinert, Tilman, and Karen Hamann. "External Validity of Studies on Aggressive Behavior in Patients with Schizophrenia: Systematic Review." Clinical Practice & Epidemiology in Mental Health 8, no. 1 (August 23, 2012): 74–80. http://dx.doi.org/10.2174/1745017901208010074.
Full textAbstract:
Studies on violence in schizophrenia use two different approaches: use of epidemiological data, and clinical studies recording direct patient data after gaining informed consent. With regard to informed consent requiring agreement and cooperation, the question arises as to what extent participants represent patients with schizophrenia and violent behaviour (external validity). We conducted a systematic literature research. In most of the studies, aggression or violence, respectively, were poorly defined. Only 5 (15.2%) studies used a cut-off score on an aggression scale. Only 6 studies (18.2%) reported the number of patients who refused to participate, and 16 (48.5%) reported the number of drop-outs. Only 3 studies (9.1%) reported a systematic comparison of participants and non-participants. We found that data which allow for the assessment of representativeness of the investigated samples are poorly reported. For most studies, doubts regarding external validity seem justified and generalisability is questionable due to possible selection bias.
24
Plebani, Mario. "External quality assessment programs: Past, present and future." Jugoslovenska medicinska biohemija 24, no. 3 (2005): 201–6. http://dx.doi.org/10.2298/jmh0503201p.
Full textAbstract:
External Quality Assurance (EQA) and Proficiency Testing (PT) programs are fundamental tools for quality evaluation and improvement in clinical laboratories. A growing body of evidence has been collected to demonstrate the usefulness of these programs for reducing inter-laboratory variation, analytical errors and for improving the "state-of-the art". The validity of EQA/PT programs is strongly affected by the quality of control materials, the design of the program, namely the ability to estimate analytical bias and imprecision, and the commitment of providers to assist in the education participant laboratories. Future perspectives of EQA/PT are the possibility to evaluate pre- and post-analytical steps, the utilization of Internet for receiving and communicating results to participant laboratories and the accreditation/certification of the programs. .
25
Lynøe, Niels, and Anders Eriksson. "Denialism Preserves Scientific Controversies: a Case Study of Abusive Head Trauma Research." Journal of Controversies in Biomedical Research 6, no. 1 (December 30, 2020): 1–6. http://dx.doi.org/10.36255/jcbmr.2020.37.
Full textAbstract:
The traditional theory of abusive head trauma requires scientific scrutiny. Those who question the validity of this theory have been accused of denialism for the purpose of obfuscating evidence in legal settings and supporting abusive caregivers. The traditional theory holds that abusive head trauma results from “shaken baby syndrome”. In reference to abusive head trauma in the absence of external signs of trauma, we argue that it is the child-protection clinicians and concerned researchers who represent denialism. We have identified three types of denialism in this area: (i) denialism of the presence of a scientific controversy; (ii) denialism of relevant scientific distinctions between abusive head trauma cases with versus without external signs of trauma; and (iii) denialism of circular reasoning as a major risk of bias. The analysis discloses that the scientific controversy pertaining to abusive head trauma is real and that it is problematic to lump together all alleged abusive head trauma, with and without external signs of trauma. Further, it has been ignored that circular reasoning results in a high risk of bias. We conclude that denialism preserves rather than promotes scientific developments on abusive head trauma research.
26
Carpenter, T., and S. Torvén. "Some dynamical properties of very strong double layers in a triple plasma device." Laser and Particle Beams 5, no. 2 (May 1987): 325–37. http://dx.doi.org/10.1017/s0263034600002809.
Full textAbstract:
We present experimental results on three dynamic properties of very strong double layers observed in a triple plasma device. First, it is observed that when an inductance of sufficient size is inserted in series with the external bias supply used to produce the double layer, disruptions in the plasma current occur accompanied by disruptions in the double layer potential. Second, it is observed that with all external reactances reduced as much as possible, a sort of jitter-motion occurs in the position of the double layer around its equilibrium position. Third, when the external bias supply is pulsed, the initial potential distribution is observed to have an essentially uniform slope, as in the case of a vacuum capacitor. The disruption phenomenon may be explained in terms of the behavior of the potential structure as a function of the bias voltage and this explanation is discussed along with the experimental evidence for its validity. A comparable understanding of the other two phenomena has not been achieved, but in both cases there are qualitative differences between the behavior reported here and what has been observed in Q-machines and these differences are discussed.
27
Mulder, Roger T., Chris Frampton, Peter R. Joyce, and Richard Porter. "Randomized Controlled Trials in Psychiatry. Part II: Their Relationship to Clinical Practice." Australian & New Zealand Journal of Psychiatry 37, no. 3 (June 2003): 265–69. http://dx.doi.org/10.1046/j.1440-1614.2003.01176.x.
Full textAbstract:
Objective: To discuss the extent to which the results of randomized controlled trials (RCTs) in psychiatry can be generalized to clinical practice. Method: Threats to internal and external validity in psychiatric RCTs are reviewed. Results: Threats to internal validity increase the possibility of bias. Psychiatric RCTs have problems with small samples, arbitrary definitions of caseness, disparate definitions of outcome and high spontaneous recovery rates. Particular issues arise in psychotherapy RCTs. Threats to external validity reduce the extent to which the results of a RCT produce a correct basis for generalization to other circumstances. These include high rates of comorbidity and sub syndromal pathology in normal clinical practice, manual-based treatment protocols and varying definitions of successful treatment. Conclusions: Randomized controlled trials remain the most robust design to investigate the effectiveness of treatments. They should be applied to important clinical questions; and carried out, as far as possible, with typical patients in the clinical conditions in which the treatment is likely to be used.
28
Ansolabehere, Stephen D., Shanto Iyengar, and Adam Simon. "Replicating Experiments Using Aggregate and Survey Data: The Case of Negative Advertising and Turnout." American Political Science Review 93, no. 4 (December 1999): 901–9. http://dx.doi.org/10.2307/2586120.
Full textAbstract:
Experiments show significant demobilizing and alienating effects of negative advertising. Although internally valid, experiments may have limited external validity. Aggregate and survey data offer two ways of providing external validation for experiments. We show that survey recall measures of advertising exposure suffer from problems of internal validity due to simultaneity and measurement error, which bias estimated effects of ad exposure. We provide valid estimates of the causal effects of ad exposure for the NES surveys using instrumental variables and find that negative advertising causes lower turnout in the NES data. We also provide a careful statistical analysis of aggregate turnout data from the 1992 Senate elections that Wattenberg and Brians (1999) recommend. These aggregate data confirm our original findings. Experiments, surveys, and aggregate data all point to the same conclusion: Negative advertising demobilizes voters.
29
Amrein-Beardsley, Audrey, and Tray Geiger. "Methodological Concerns About the Education Value-Added Assessment System (EVAAS): Validity, Reliability, and Bias." SAGE Open 10, no. 2 (April 2020): 215824402092222. http://dx.doi.org/10.1177/2158244020922224.
Full textAbstract:
The Education Value-Added Assessment System (EVAAS), the value-added model (VAM) sold by the international business analytics software company SAS Institute Inc., is advertised as offering “precise, reliable and unbiased results that go far beyond what other simplistic [value-added] models found in the market today can provide.” In this study, we investigated these claims, as well as others pertaining to the validity or truthfulness of model output, by conducting analyses on more than 1,700 teachers’ EVAAS results (i.e., actual EVAAS output to which no other external scholars have had access prior) from the Houston Independent School District (HISD). We found the EVAAS to perform, overall, in line with other VAMs in terms of validity and reliability, although it yielded possibly more biased value-added estimates than other VAMs due to differences in teacher’s EVAAS scores based on school-level student composition factors.
30
Wang, Gang, Sarita Schoenebeck, Haitao Zheng, and Ben Zhao. "''Will Check-in for Badges'': Understanding Bias and Misbehavior on Location-Based Social Networks." Proceedings of the International AAAI Conference on Web and Social Media 10, no. 1 (August 4, 2021): 417–26. http://dx.doi.org/10.1609/icwsm.v10i1.14718.
Full textAbstract:
Social computing researchers are using data from location-based social networks (LBSN), e.g., "Check-in" traces, as approximations of human movement. Recent work has questioned the validity of this approach, showing large discrepancies between check-in data and actual user mobility. To further validate and understand such discrepancies, we perform a crowdsourced study of Foursquare users that seeks to a) quantify bias and misrepresentation in check-in datasets and the impact of self-selection in prior studies, and b) understand the motivations behind misrepresentation of check-ins, and the potential impact of any system changes designed to curtail such misbehavior. Our results confirm the presence of significant misrepresentation of location check-ins on Foursquare. They also show that while "extraneous" check-ins are motivated by external rewards provided by the system, "missing" check-ins are motivated by personal concerns such as location privacy. Finally, we discuss the broader implications of our findings to the use of check-in datasets in future research on human mobility.
31
Susongko, P., Y. Arfiani, and M. Kusuma. "Determination of Gender Differential Item Functioning in Tegal Students' Scientific Literacy Skills with Integrated Science (SLiSIS) Test Using Rasch Model." Jurnal Pendidikan IPA Indonesia 10, no. 2 (June 30, 2021): 270–81. http://dx.doi.org/10.15294/jpii.v10i2.26775.
Full textAbstract:
The emergence of Differential Item Functioning (DIF) indicates an external bias in an item. This study aims to identify items at scientific literacy skills with integrated science (SLiSIS) test that experience DIF based on gender. Moreover, it is analyzed the emergence of DIF, especially related to the test construct measured, and concluded on how far the validity of the SLiSIS test from the construct validity of consequential type. The study was conducted with a quantitative approach by using a survey or non-experimental methods. The samples of this study were the responses of the SLiSIS test taken from 310 eleventh-grade high school students in the science program from SMA 2 and SMA 3 Tegal. The DIF analysis technique used Wald Test with the Rasch model. From the findings, eight items contained DIF in a 95 % level of trust. In 99 % level of trust, three items contained DIF, items 1, 6, and 38 or 7%. The DIF is caused by differences in test-takers ability following the measured construct, so it is not a test bias. Thus, the emergence of DIF on SLiSIS test items does not threaten the construct validity of the consequential type.
32
Mathie, Robert, Yvonne Fok, Petter Viksveen, Aaron To, and Jonathan Davidson. "Systematic Review and Meta-Analysis of Randomised, Other-than-Placebo Controlled, Trials of Non-Individualised Homeopathic Treatment." Homeopathy 108, no. 02 (January 30, 2019): 088–101. http://dx.doi.org/10.1055/s-0038-1677481.
Full textAbstract:
Introduction This study focuses on randomised controlled trials (RCTs) of non-individualised homeopathic treatment (NIHT) in which the control (comparator) group was other than placebo (OTP). Objectives To determine the comparative effectiveness of NIHT on health-related outcomes in adults and children for any given condition that has been the subject of at least one OTP-controlled trial. For each study, to assess its risk of bias and to determine whether its study attitude was predominantly ‘pragmatic’ or ‘explanatory’. Methods Systematic review. For each eligible trial, published in the peer-reviewed literature up to the end of 2016, we assessed its risk of bias (internal validity) using the seven-domain Cochrane tool, and its relative pragmatic or explanatory attitude (external validity) using the 10-domain PRECIS tool. We grouped RCTs by whether these examined IHT as alternative treatment (study design 1a), adjunctively with another intervention (design 1b), or compared with no intervention (design 2). RCTs were sub-categorised as superiority trials or equivalence/non-inferiority trials. For each RCT, we designated a single ‘main outcome measure’ to use in meta-analysis: ‘effect size’ was reported as odds ratio (OR; values > 1 favouring homeopathy) or standardised mean difference (SMD; values < 0 favouring homeopathy). Results Seventeen RCTs, representing 15 different medical conditions, were eligible for study. Three of the trials were more pragmatic than explanatory, two were more explanatory than pragmatic, and 12 were equally pragmatic and explanatory. Fourteen trials were rated ‘high risk of bias’ overall; the other three trials were rated ‘uncertain risk of bias’ overall. Ten trials had data that were extractable for analysis. Significant heterogeneity undermined the planned meta-analyses or their meaningful interpretation. For the three equivalence or non-inferiority trials with extractable data, the small, non-significant, pooled effect size (SMD = 0.08; p = 0.46) was consistent with a conclusion that NIHT did not differ from treatment by a comparator (Ginkgo biloba or betahistine) for vertigo or (cromolyn sodium) for seasonal allergic rhinitis. Conclusions The current data preclude a decisive conclusion about the comparative effectiveness of NIHT. Generalisability of findings is restricted by the limited external validity identified overall. The highest intrinsic quality was observed in the equivalence and non-inferiority trials of NIHT.
33
Fischer, Elisabeth, and Martin Hänze. "Bias hypotheses under scrutiny: investigating the validity of student assessment of university teaching by means of external observer ratings." Assessment & Evaluation in Higher Education 44, no. 5 (December 26, 2018): 772–86. http://dx.doi.org/10.1080/02602938.2018.1535647.
Full text
34
Wiedemann, G., S. Klingberg, A. Wittorf, A. Fischer, and G. Buchkremer. "P02.245 External validity of randomised clinical trials (RCT'S): Is there a selection bias in psychotherapy treatment studies of schizophrenia?" European Psychiatry 15, S2 (October 2000): 387s—388s. http://dx.doi.org/10.1016/s0924-9338(00)94653-4.
Full text
35
Heggestad, Eric D., Steven Rogelberg, Adrian Goh, and Frederick L. Oswald. "Considering the Effects of Nonresponse on Correlations Between Surveyed Variables." Journal of Personnel Psychology 14, no. 2 (July 17, 2015): 91–103. http://dx.doi.org/10.1027/1866-5888/a000129.
Full textAbstract:
Nonresponse to organizational surveys is a vexing problem. Although scholars have a reasonable understanding of how systematic nonresponse influences estimates of population means, they are likely to have less context for understanding how it impacts correlations. We present the results of a simulation study designed to provide a frame of reference for understanding the extent to which systematic nonresponse can bias observed correlations between surveyed variables. Although there were cases where notable levels of bias were observed in the correlations, the majority of situations simulated resulted in mean observed correlations that were within .05 of the true correlation. The variety of situations simulated allows researchers to evaluate the external validity of observed correlations in their data – a critical goal for survey researchers in practice and academics.
36
Wasmann, Karin A., Pieta Wijsman, Susan van Dieren, Willem Bemelman, and Christianne Buskens. "Partially randomised patient preference trials as an alternative design to randomised controlled trials: systematic review and meta-analyses." BMJ Open 9, no. 10 (October 2019): e031151. http://dx.doi.org/10.1136/bmjopen-2019-031151.
Full textAbstract:
ObjectiveRandomised controlled trials (RCT) are the gold standard to provide unbiased data. However, when patients have a treatment preference, randomisation may influence participation and outcomes (eg, external and internal validity). The aim of this study was to assess the influence of patients’ preference in RCTs by analysing partially randomised patient preference trials (RPPT); an RCT and preference cohort combined.DesignSystematic review and meta-analyses.Data sourcesMEDLINE, Embase, PsycINFO and the Cochrane Library.Eligibility criteria for selecting studiesRPPTs published between January 2005 and October 2018 reporting on allocation of patients to randomised and preference cohorts were included.Data extraction and synthesisTwo independent reviewers extracted data. The main outcomes were the difference in external validity (participation and baseline characteristics) and internal validity (lost to follow-up, crossover and the primary outcome) between the randomised and the preference cohort within each RPPT, compared in a meta-regression using a Wald test. Risk of bias was not assessed, as no quality assessment for RPPTs has yet been developed.ResultsIn total, 117 of 3734 identified articles met screening criteria and 44 were eligible (24 873 patients). The participation rate in RPPTs was >95% in 14 trials (range: 48%–100%) and the randomisation refusal rate was >50% in 26 trials (range: 19%–99%). Higher education, female, older age, race and prior experience with one treatment arm were characteristics of patients declining randomisation. The lost to follow-up and cross-over rate were significantly higher in the randomised cohort compared with the preference cohort. Following the meta-analysis, the reported primary outcomes were comparable between both cohorts of the RPPTs, mean difference 0.093 (95% CI −0.178 to 0.364, p=0.502).ConclusionsPatients’ preference led to a substantial proportion of a specific patient group refusing randomisation, while it did not influence the primary outcome within an RPPT. Therefore, RPPTs could increase external validity without compromising the internal validity compared with RCTs.PROSPERO registration numberCRD42019094438.
37
PEREIRA, RODRIGO M., GLÍCIA M. Z. GRECO, ANDREIA M. MOREIRA, PABLO F. CHAGAS, IVO S. CALDAS, REGGIANI V. GONÇALVES, and RÔMULO D. NOVAES. "Applicability of plant-based products in the treatment ofTrypanosoma cruziandTrypanosoma bruceiinfections: a systematic review of preclinicalin vivoevidence." Parasitology 144, no. 10 (June 5, 2017): 1275–87. http://dx.doi.org/10.1017/s0031182017000634.
Full textAbstract:
SUMMARYChagas disease and sleeping sickness are neglected tropical diseases closely related to poverty, for which the development of plant-derived treatments has not been a promising prospect. Thus, we systematicaly review the preclinicalin vivoevidence on the applicability of plant-based products in the treatment ofTrypanosoma cruziandTrypanosoma bruceiinfections. Characteristics such as disease models, treatments, toxicological safety and methodological bias were analysed. We recovered 66 full text articles from 16 countries investigating 91 plant species. The disease models and treatments were highly variable. Most studies used native (n= 36, 54·54%) or exotic (n= 30, 45·46%) plants with ethnodirected indication (n= 45, 68·18%) for trypanosomiasis treatment. Complete phytochemical screening and toxicity assays were reported in only 15 (22·73%) and 32 (48·49%) studies, respectively. The currently available preclinical evidence is at high risk of bias. The absence of or incomplete characterization of animal models, treatment protocols, and phytochemical/toxicity analyses impaired the internal validity of the individual studies. Contradictory results of a same plant species compromise the external validity of the evidence, making it difficult determine the effectiveness, safety and biotechnological potential of plant-derived products in the development of new anti-infective agents to treatT. cruziandT. bruceiinfections.
38
Jones, Richard N., and Joseph J. Gallo. "Education Bias in the Mini-Mental State Examination." International Psychogeriatrics 13, no. 3 (September 2001): 299–310. http://dx.doi.org/10.1017/s1041610201007694.
Full textAbstract:
Education is correlated with cognitive status assessment. Concern for test bias has led to questions of equivalent construct validity across education groups. Following the work of previous researchers, we submitted Mini-Mental State Examination (MMSE) responses to external validation analyses. Subjects were older participants in the Epidemiologic Catchment Area study (age 50-98). Little evidence for test bias against those with low education was found. The correlation of MMSE scores and age was equivalent across high-and low-education groups (−.29 vs. −.27, p = .48), as was the correlation of MMSE scores and activities of daily living (ADL) functioning (−.23 vs. −.27, p = .42). The MMSE displayed significantly higher internal consistency reliability in the low-education group (.75 vs .72, p = .04). The MMSE did not predict functional decline over 1 year or mortality over 13 years differently by level of educational attainment. Evidence for sex bias was found. The MMSE was more highly correlated with age among women than among men (−.28 vs. −.21, p < .001). The MMSE was more highly correlated with ADL impairment among women than among men (−.30 vs. −.17, p = .01). The MMSE predicted mortality differently according to participant sex (p = 0.53). The lack of evidence for bias provides little support to proposals to adjust MMSE scores according to level of education.
39
Montalvo-Pérez, Almudena, Lidia B. Alejo, Pedro L. Valenzuela, Mario Castellanos, Jaime Gil-Cabrera, Eduardo Talavera, Alejandro Lucia, and David Barranco-Gil. "Validity of the Favero Assioma Duo Power Pedal System for Measuring Power Output and Cadence." Sensors 21, no. 7 (March 24, 2021): 2277. http://dx.doi.org/10.3390/s21072277.
Full textAbstract:
Cycling power meters enable monitoring external loads and performance changes. We aimed to determine the concurrent validity of the novel Favero Assioma Duo (FAD) pedal power meter compared with the crank-based SRM system (considered as gold standard). Thirty-three well-trained male cyclists were assessed at different power output (PO) levels (100–500 W and all-out 15-s sprints), pedaling cadences (75–100 rpm) and cycling positions (seating and standing) to compare the FAD device vs. SRM. No significant differences were found between devices for cadence nor for PO during all-out efforts (p > 0.05), although significant but small differences were found for efforts at lower PO values (p < 0.05 for 100–500 W, mean bias 3–8 W). A strong agreement was observed between both devices for mean cadence (ICC > 0.87) and PO values (ICC > 0.81) recorded in essentially all conditions and for peak cadence (ICC > 0.98) and peak PO (ICC > 0.99) during all-out efforts. The coefficient of variation for PO values was consistently lower than 3%. In conclusion, the FAD pedal-based power meter can be considered an overall valid system to record PO and cadence during cycling, although it might present a small bias compared with power meters placed on other locations such as SRM.
40
Chamorro, Claudio, Miguel Arancibia, Benjamín Trigo, Leónidas Arias-Poblete, and Daniel Jerez-Mayorga. "Absolute Reliability and Concurrent Validity of Hand-Held Dynamometry in Shoulder Rotator Strength Assessment: Systematic Review and Meta-Analysis." International Journal of Environmental Research and Public Health 18, no. 17 (September 3, 2021): 9293. http://dx.doi.org/10.3390/ijerph18179293.
Full textAbstract:
The purpose of this study is to establish the absolute reliability between hand-held dynamometers (HHDs) and concurrent validity between HHDs and isokinetic dynamometers (IDs) in shoulder rotator strength assessment. The Medline, CINAHL, and Central databases were searched for relevant studies up to July 2020. Absolute reliability was determined by test–retest studies presenting standard error of measurement (SEM%) and/or minimal detectable change (MDC%) expressed as percentage of the mean. Studies considering intra-class correlation coefficient (ICC) between IDs and HHDs were considered for concurrent validity. The risk of bias and the methodological quality were evaluated according to COnsensus-based Standards for the selection of health Measurement INstruments (COSMIN). Thirteen studies were included in the meta-analysis. Shoulder internal rotator strength assessment MDC% was 0.78%, 95% confidence interval (CI) −5.21 to 3.66, while shoulder external rotators MDC% was 3.29%, CI −2.69 to 9.27. ICC between devices was 0.94, CI (0.91 to 0.96) for shoulder internal rotators and 0.92, IC (0.88 to 0.97) for shoulder external rotators. Very high correlation was found for shoulder rotator torque assessment between HHDs and IDs. The COSMIN checklist classified the selected studies as adequate and inadequate.
41
Hunniford, Victoria T., Joshua Montroy, Dean A. Fergusson, Marc T. Avey, Kimberley E. Wever, Sarah K. McCann, Madison Foster, et al. "Epidemiology and reporting characteristics of preclinical systematic reviews." PLOS Biology 19, no. 5 (May 5, 2021): e3001177. http://dx.doi.org/10.1371/journal.pbio.3001177.
Full textAbstract:
In an effort to better utilize published evidence obtained from animal experiments, systematic reviews of preclinical studies are increasingly more common—along with the methods and tools to appraise them (e.g., SYstematic Review Center for Laboratory animal Experimentation [SYRCLE’s] risk of bias tool). We performed a cross-sectional study of a sample of recent preclinical systematic reviews (2015–2018) and examined a range of epidemiological characteristics and used a 46-item checklist to assess reporting details. We identified 442 reviews published across 43 countries in 23 different disease domains that used 26 animal species. Reporting of key details to ensure transparency and reproducibility was inconsistent across reviews and within article sections. Items were most completely reported in the title, introduction, and results sections of the reviews, while least reported in the methods and discussion sections. Less than half of reviews reported that a risk of bias assessment for internal and external validity was undertaken, and none reported methods for evaluating construct validity. Our results demonstrate that a considerable number of preclinical systematic reviews investigating diverse topics have been conducted; however, their quality of reporting is inconsistent. Our study provides the justification and evidence to inform the development of guidelines for conducting and reporting preclinical systematic reviews.
42
Hanna, Nawar, Quoc-Dien Trinh, Jesse Sammon, Thomas Seisen, Malte Vetterlein, Raphael Brandao Moreira, Mark A. Preston, et al. "Is neoadjuvant chemotherapy beneficial before radical cystectomy? Examining the external validity of the SWOG-8710 trial." Journal of Clinical Oncology 35, no. 6_suppl (February 20, 2017): 331. http://dx.doi.org/10.1200/jco.2017.35.6_suppl.331.
Full textAbstract:
331 Background: The use of neoadjuvant chemotherapy (NAC) before radical cystectomy (RC) is supported by results from several randomized control trials, including SWOG-8710. We sought to test the applicability of the SWOG-8710 study in the general population. Methods: We used the National Cancer Data Base (NCDB) to identify patients with non-metastatic muscle-invasive urothelial carcinoma of the bladder who underwent RC between 2004 and 2012. The primary endpoint was overall survival (OS). Secondary endpoints were rates of downstaging (pT0), positive pathologic lymph nodes (pN+), margin status, postoperative readmission, length of hospital stay (LOS), and 30 and 90-day postoperative mortality rates. OS comparison using Cox regression analysis was conducted. Furthermore, logistic regression models examining secondary outcomes were fitted. To adjust for potential selection bias, propensity score weighted analyses were performed. Results: Of 8732 patients who underwent RC, 1619 (19%) received NAC. Compared to the SWOG-8710 cohort, our population was older, more commonly female (p=0.002), and had higher clinical stage (p<0.001). Following propensity score adjustment, receipt of NAC was associated with an OS benefit (Hazard Ratio [HR]: 0.88, p=0.017). On secondary outcome analysis, higher downstaging rates (Odds Ratio [OR]: 5.03, p<0.001) and lower 30-day (OR: 0.49, p=0.019) and 90-day (OR: 0.61, p=0.009) postoperative mortality rates were recorded in patients who received NAC. Conclusions: Despite baseline differences between patients from the SWOG-8710 trial and general urologic practice, NAC is associated with an OS advantage relative to RC alone. Continued efforts should focus on promoting the use of NAC in appropriate patients.
43
Garrocho-Rangel, Arturo, Socorro Ruiz-Rodríguez, César Gaitán-Fonseca, and Amaury Pozos-Guillén. "Randomized Clinical Trials in Pediatric Dentistry: Application of Evidence-Based Dentistry through the CONSORT Statement." Journal of Clinical Pediatric Dentistry 43, no. 4 (January 1, 2019): 219–30. http://dx.doi.org/10.17796/1053-4625-43.4.1.
Full textAbstract:
In order to include appropriate informed decisions on dental therapeutic or preventive procedures in children, Pediatric Dentists should apply the fundamentals of “Evidence-Based Dentistry” (EBD). This oral health approach assists clinicians in understanding and applying the most relevant research published on evidence in the clinical setting when treating their patients. One of the crucial steps of EBD is to critically appraise and use the primary articles about therapy or prevention, namely, Randomized Clinical Trials (RCT), the study design that best addresses the questions related with these clinical areas. The aim of the present paper was to provide the basic concepts and an example of how to critically read and understand articles on RCT studies in Pediatric Dentistry employing the CONSORT statement, a process that involves assessing the reliability of results, risk of bias (internal validity), and applicability of reported clinical findings (external validity).
44
Wilner, Lauren, Emma Wells, Michael Ritter, Jean Marcel Casimir, Kenneth Chui, and Daniele Lantagne. "Sustained use in a relief-to-recovery household water chlorination program in Haiti: comparing external evaluation findings with internal supervisor and community health worker monitoring data." Journal of Water, Sanitation and Hygiene for Development 7, no. 1 (January 12, 2017): 56–66. http://dx.doi.org/10.2166/washdev.2017.035.
Full textAbstract:
After the January 2010 earthquake in Haiti, an existing development program promoting household water treatment with chlorine rapidly expanded and provided relief to 15,000 earthquake-affected households. Initially, 157 community health workers (CHWs) distributed chlorine tablets; ten months later, CHWs began selling locally manufactured solution. The program was externally evaluated in March and November 2010; 77–90% of recipients had free chlorine residual (FCR) in household water. Internal monitoring by three supervisors and 157 CHWs also began in 2010. We analyzed results from 9,832 supervisor and 80,371 CHW monitoring visits conducted between 2010 and 2014 to assess: whether success continued in the rehabilitation phase; internal data validity; and factors impacting adoption. In 2010, 72.7% of supervisor visits documented total chlorine residual (TCR) comparable to external evaluation results. TCR presence was associated with certain supervisors/CHWs, earlier program year and month (in 2014, supervisor visits TCR presence dropped to 52.1%), living in plains (not mountainous) regions, and certain calendar months. CHW visits recorded 18.1% higher TCR presence than supervisor visits, indicating bias. Our results document a program with sustained (although slightly declining) household chlorination use, provide insight into validity in internal monitoring, and inform discussions on the value of linking successful development programs to emergency relief, rehabilitation, and development.
45
Lovell, Ric, Sam Halley, Jason Siegler, Tony Wignell, Aaron J. Coutts, and Tim Massard. "Use of Numerically Blinded Ratings of Perceived Exertion in Soccer: Assessing Concurrent and Construct Validity." International Journal of Sports Physiology and Performance 15, no. 10 (November 1, 2020): 1430–36. http://dx.doi.org/10.1123/ijspp.2019-0740.
Full textAbstract:
Purpose: To examine the concurrent and construct validity of numerically blinded ratings of perceived exertion (RPEs). Methods: A total of 30 elite male youth soccer players (age 16.7 [0.5] y) were monitored during training and matches over a 17-wk in-season period. The players’ external loads were determined via raw 10-Hz global positioning system. Heart rate (HR) was collected continuously and expressed as Bannister and Edwards training impulses, and minutes >80% of the players predetermined the maximum HR by the Yo-Yo Intermittent Recovery Test Level 1. RPE was collected confidentially 10 to 15 min after training/matches using 2 methods: (1) a traditional verbal response to the 0 to 100 category-ratio “centiMax” scale (RPE) and (2) numerically blinded RPE centiMax scale (RPEblind) with the response selected manually via a 5 × 7-in tablet “slider.” The RPE and RPEblind were divided by 10 and multiplied by the duration to derive the sessional RPE. Linear mixed models compared ratings, and within-subject repeated-measures correlations assessed the sessional RPE versus HR and external load associations. Results: There were no differences between the RPE and RPEblind (0.19; 95% confidence intervals, −0.59 to 0.20 au, P = .326) or their session values (13.5; 95% confidence intervals, −17.0 to 44.0 au, P = .386), and the ratings were nearly perfectly correlated (r = .96). The associations between the sessional RPE versus HR and external load metrics were large to very large (r = .65–.81), with no differences between the RPE methods (P ≥ .50). The RPEblind also reduced verbal anchor clustering and integer bias by 11% and 50%, respectively. Conclusions: RPEblind demonstrated concurrent and construct validity versus the traditional method, and may be used in situations where practitioners have concerns regarding the authenticity of athlete ratings.
46
Pritchett, Lant, and Justin Sandefur. "Learning from Experiments when Context Matters." American Economic Review 105, no. 5 (May 1, 2015): 471–75. http://dx.doi.org/10.1257/aer.p20151016.
Full textAbstract:
Suppose a policymaker is interested in the impact of an existing social program. Impact estimates using observational data suffer potential bias, while unbiased experimental estimates are often limited to other contexts. This creates a practical trade-off between internal and external validity for evidence-based policymaking. We explore this trade-off empirically for several common policies analyzed in development economics, including microcredit, migration, and education interventions. Based on mean-squared error, non-experimental evidence within context outperforms experimental evidence from another context. This advantage declines, but may not reverse, with experimental replication. We offer four reasons these findings are of general relevance to policy evaluation.
47
Harrison, Sian, Fiona Alderdice, and Maria A. Quigley. "External validity of prevalence estimates from the national maternity surveys in England: The impact of response rate." PLOS ONE 15, no. 11 (November 30, 2020): e0242815. http://dx.doi.org/10.1371/journal.pone.0242815.
Full textAbstract:
Background Prevalence estimates from surveys with low response rates are prone to non-response bias if respondents and non-respondents differ on the outcome of interest. This study assessed the external validity of prevalence estimates of selected maternity indicators from four national maternity surveys in England which had similar survey methodology but different response rates. Methods A secondary analysis was conducted using data from the national maternity surveys in 2006 (response rate = 63%), 2010 (response rate = 54%), 2014 (response rate = 47%) and 2018 (response rate = 29%). Unweighted and (for the 2014 and 2018 surveys) weighted survey prevalence estimates (with 95%CIs) of caesarean section, preterm birth, low birthweight and breastfeeding initiation were validated against population-based estimates from routine data. Results The external validity of the survey estimates varied across surveys and by indicator. For caesarean section, the 95%CIs for the unweighted survey estimates included the population-based estimates for all surveys. For preterm birth and low birthweight, the 95%CIs for the unweighted survey estimates did not include the population-based estimates for the 2006 and 2010 surveys (or the 2014 survey for preterm birth). For breastfeeding initiation, the 95%CIs for the unweighted survey estimates did not include the population-based estimates for any survey. For all indicators, the effect of weighting (on the 2014 and 2018 survey estimates) was mostly a shift towards the population-based estimates, yet the 95%CIs for the weighted survey estimates of breastfeeding initiation did not include the population-based estimates. Conclusion There were no clear differences in the external validity of prevalence estimates according to survey response rate suggesting that prevalence estimates may still be valid even when survey response rates are low. The survey estimates tended to become closer to the population-based estimates when weights were applied, yet the effect was insufficient for breastfeeding initiation estimates.
48
Morgan, Paul L., George Farkas, Michael Cook, Natasha M. Strassfeld, Marianne M. Hillemeier, Wik Hung Pun, Yangyang Wang, and Deborah L. Schussler. "Are Hispanic, Asian, Native American, or Language-Minority Children Overrepresented in Special Education?" Exceptional Children 84, no. 3 (February 13, 2018): 261–79. http://dx.doi.org/10.1177/0014402917748303.
Full textAbstract:
We conducted a best-evidence synthesis of 22 studies to examine whether systemic bias explained minority disproportionate overrepresentation in special education. Of the total regression model estimates, only 7/168 (4.2%), 14/208 (6.7%), 2/37 (5.4%), and 6/91 (6.6%) indicated statistically significant overrepresentation for Hispanic, Asian, Native American, and English language learner (ELL) or language-minority children, respectively. Among studies with the strongest internal and external validity, none of the 90 estimates (i.e., 0%) indicated overrepresentation attributable to racial or ethnic bias. Of the 18 estimates for language-minority and ELL children combined, only 3 (16.7%) indicated overrepresentation attributable to language use. Two of the 4 ELL-specific estimates (50%) indicated that children receiving English-as-a-second-language services may be overrepresented in special education. Overall, and replicating findings from a prior best-evidence synthesis, this synthesis indicated that children are underidentified as having disabilities based on their race or ethnicity and language use.
49
Oliveira, Matheus Lima, Isabela Christina Ferreira, Kariny Realino Ferreira, Gabriela Silveira-Nunes, Michelle Almeida Barbosa, and Alexandre Carvalho Barbosa. "Validity of an Inexpensive Hanging Scale During Isometric Shoulder Movements." Journal of Sport Rehabilitation 29, no. 8 (November 1, 2020): 1218–21. http://dx.doi.org/10.1123/jsr.2019-0255.
Full textAbstract:
Context: Strength assessment is essential to prescribe exercise in sports and rehabilitation. Low-cost valid equipment may allow continuous monitoring of training. Objective: To examine the validity of a very low-cost hanging scale by comparing differences in the measures of peak force to a laboratory grade load cell during shoulder abduction, flexion, extension, and internal and external rotations. Design: Analytical study. Participants: Thirty-two healthy subjects (18 women, age 26 [10] y, height 172 [8] cm, mass 69 [13] kg, body mass index 23 [4] kg/m2). Main Outcome Measures: The dependent variable was the maximal peak force (in kilogram-force). The independent variable was the instrument (laboratory grade load cell and hanging scale). Results: No differences were observed while comparing the results. The intraclass correlation coefficients1,1 ranged from .96 to .99, showing excellent results. The Cronbach alpha test also returned >.99 for all comparisons. The SEM ranged from 0.02 to 0.04 kgf, with an averaged SD from 0.24 to 0.38 kgf. The correlation was classified as high for all tested movements (r > .99; P < .001), with excellent adjusted coefficients of determination (.96 < r2 < .99). Bland–Altman results showed high levels of agreement with bias ranging from 0.27 to 0.48. Conclusions: Hanging scale provides valid measures of isometric strength with similar output measures as laboratory grade load cell.
50
Charron, Nicholas. "Do corruption measures have a perception problem? Assessing the relationship between experiences and perceptions of corruption among citizens and experts." European Political Science Review 8, no. 1 (January 14, 2015): 147–71. http://dx.doi.org/10.1017/s1755773914000447.
Full textAbstract:
How well do corruption perception measures reflect actual levels of public sector corruption? Leading cross-national corruption perception measures have come under much theoretical and empirical scrutiny in recent years, with serious implications for the validity and reliability of the data in this ever growing sub-field. Critics argue that perceptions – in particular those of outside experts – do not reflect actual corruption in that they are far too ‘noisy’ or simply biased by external factors such as economic performance. Moreover, a number of recent empirical studies, focused on developing areas, have put forth evidence that outside expert assessments of corruption correspond little, if at all, with the experiences and views of actual citizens, and that such a lack of correspondence demonstrates pessimism for existing perception measures. This study offers a systematic analysis of the empirical strength of corruption perception measures in a previously unexplored area in this debate – Europe. Using new survey data collected by the author based on 85,000 European respondents in 24 countries, this issue is analyzed directly, addressing several contemporary critiques of the data. First, perceptions of citizens with, and without, personal corruption experience are compared at both the national and sub-national level in Europe. Second, external factors are checked, which might bias the extent to which citizens perceive corruption relative to how much actual corruption exists in countries and regions. Finally, expert perception indicators and citizen perceptions and experiences are compared. In summary, strong counter-evidence is found to the prevailing pessimistic claims in the literature – the consistency between actual reported corruption, as well as citizen and expert perceptions of corruption, is remarkably high and such perceptions are swayed little by ‘outside noise’. I conclude that, although existing corruption measures certainly have their share of problems, concerns regarding the validity and bias of perceptions have, perhaps, been overstated.