Academic literature on the topic 'Buckley-James regression'

This paper develops a new empirical likelihood method for semiparametric linear regression with a completely unknown error distribution and right censored survival data. The method is based on the Buckley-James (1979) estimating equation. It inherits some appealing properties of the complete data empirical likelihood method. For example, it does not require variance estimation which is problematic for the Buckley-James estimator. We also extend our method to incorporate auxiliary information. We compare our method with the synthetic data empirical likelihood of Li and Wang (2003) using simulations. We also illustrate our method using Stanford heart transplantation data.

In survival analysis, proportional hazards models are commonly used in a distribution-free way for regression where the response variable has been right-censored. However, often a simple linear model may be more appropriate for the data. We present an overview of the linear regression method of Buckley and James (1979) as an interesting distribution-free alternative. It is a method providing consistent parameter estimates, and, through simulation, has been successfully appraised in the literature in comparison to other regression methods. The model is fitted iteratively, and censored points in the scatterplot are moved to estimated positions as if they had been observed without censoring. In this paper we will concentrate on scatterplot effects, model fitting and diagnostics.

<p><strong>List of abstracts and authors:</strong></p><p><strong>1. Bipolar disorder not otherwise specified -overdiagnosed or underdiagnosed?</strong></p><p>E Allers</p><p><strong>2. The prognosis of major depression untreated and treated: Does the data reflect the true picture of the prognosis of this very common disorder?</strong></p><p>E Allers</p><p><strong>3. Can we prolong our patients' life expectancy? Providing a better quality of life for patients with severe mental illness</strong></p><p>O A Betencourt</p><p><strong>4. The scope of ECT practice in South Africa</strong></p><p>J Benson-Martin, P Milligan</p><p><strong>5. Biomarkers for schizophrenia: Can we evolve like cancer therapeutics?</strong></p><p>P Buckley<strong></strong></p><p><strong>6. Relapse in schizophrenis: Major challenges in prediction and prevention</strong></p><p>P Buckley</p><p><strong>7. Informed consent in biological treatments: The right to know the duty to inform</strong></p><p><strong></strong>I Chetty</p><p><strong>8. Effectiveness of a long-acting injectable antipsychotic plus an assertive monitoring programme in first-episode schizophrenia</strong></p><p><strong></strong>B Chiliza, L Asmal, O Esan, A Ojagbemi, O Gureje, R Emsley</p><p><strong>9. Name, shame, fame</strong></p><p>P Cilliers</p><p><strong>10. Can we manage the increasing incidence of violent raging children? We have to!</strong></p><p>H Clark</p><p><strong>11. Serotonin, depression and antidepressant action</strong></p><p>P Cowen</p><p><strong>12. Prevalence and correlates of comorbid psychiatris illness in patients with heroin use disorder admitted to Stikland Opioid Detoxification Unit</strong></p><p>L Dannatt, K J Cloete, M Kidd, L Weich</p><p><strong>13. Investigating the association between diabetes mellitus, depression and psychological distress in a cohort of South African teachers</strong></p><p>A K Domingo, S Seedat, T M Esterhuizen, C Laurence, J Volmink, L Asmal</p><p><strong>14. Neuropeptide S -emerging evidence for a role in anxiety</strong></p><p>K Domschke</p><p><strong>15. Pathogenetics of anxiety</strong></p><p>K Domschke</p><p><strong>16. The effects of HIV on the fronto-striatal system</strong></p><p>S du Plessis, M Vink, J Joska, E Koutsilieri, C Scheller, B Spottiswoode, D Stein, R Emsley</p><p><strong>17. Effects of acute antipsychotic treatment on brain morphology in schizophrenia</strong></p><p>R Emsley, L Asmal, B Chiliza, S du Plessis, J Carr, A Goosen, M Kidd, M Vink, R Kahn</p><p><strong>18. Development of a genetic database resource for monitoring of breast cancer patients at risk of physical and psychological complications</strong></p><p>K Grant, F J Cronje, K Botha, J P Apffelstaedt, M J Kotze</p><p><strong>19. Unipolar mania reconsidered: Evidence from a South African study</strong></p><p><strong></strong>C Grobler</p><p><strong>20. Antipsychotic-induced movement disorders: Occurence and management</strong></p><p>P Haddad</p><p><strong>21. The place of observational studies in assessing the effectiveness of long-acting injectable antipsychotics</strong></p><p>P Haddad</p><p><strong>22. Molecular mechanisms of d-cycloserine in fear extinction: Insights from RNS sequencing</strong></p><p>S Hemmings, S Malan-Muller, L Fairbairn, M Jalali, E J Oakeley, J Gamieldien, M Kidd, S Seedat</p><p><strong>23. Schizophrenia: The role of inflammation</strong></p><p>DC Henderson</p><p><strong>24. Addictions: Emergent trends and innovations</strong></p><p>V Hitzeroth</p><p><strong>25. The socio-cultural-religious context of biological psychiatric practice</strong></p><p>B Janse van Rensburg</p><p><strong>26. Biochemical markers for identifying risk factors for disability progression in multiple sclerosis</strong></p><p><strong></strong>S Janse van Rensburg, M J Kotze, F J Cronje, W Davis, K Moremi, M Jalali Sefid Dashti, J Gamieldien, D Geiger, M Rensburg, R van Toorn, M J de Klerk, G M Hon, T Matsha, S Hassan, R T Erasmus</p><p><strong>27. Alcohol-induced psychotic disorder: Brain perfusion and psychopathology - before and after antipsychotic treatment</strong></p><p>G Jordaan, J M Warwick, D G Nel, R Hewlett, R Emsley</p><p><strong>28.'Pump and dump': Harm reduction strategies for breastfeeding while using substances</strong></p><p>L Kramer</p><p><strong>29. Adolescent neuropsychiatry - an emerging field in South African adolescent psychiatric services</strong></p><p>A Lachman</p><p><strong>30. Recovery versus remission, or what it means to be healthy for a psychiatric patient?</strong></p><p>B Latecki</p><p><strong>31. Holistic methods utilised to normalise behaviours in youth diagnosed with neuro-biochemical disorders</strong></p><p>P Macqueen</p><p><strong>32. Candidate genes and novel polymorphisms for anxiety disorder in a South African cohort</strong></p><p>N McGregor, J Dimatelis, S M J Hemmings, C J Kinnear, D Stein, V Russel, C Lochner</p><p><strong>33. Higher visual functioning</strong></p><p>A Moodley</p><p><strong>34. The effects of prenatal methylmercury exposure on trace element and antioxidant levels in rat offspring following 6-hydroxydopamine-induced neuronal insult</strong></p><p>Z M Moosa, W M U Daniels, M V Mabandla</p><p><strong>35. Paediatric neuropsychiatric movement disorders</strong></p><p>L Mubaiwa</p><p><strong>36. The South African national female offenders study</strong></p><p>M Nagdee, L Artz, C de Clercq, P de Wet, H Erlacher, S Kaliski, C Kotze, L Kowalski, J Naidoo, S Naidoo, J Pretorius, M Roffey, F Sokudela, U Subramaney</p><p><strong>37. Neurobiological consequences of child abuse</strong></p><p>C Nemeroff</p><p><strong>38. What do Stellenbosch Unviversity medical students think about psychiatry - and why should we care?</strong></p><p>G Nortje, S Suliman, K Seed, G Lydall, S Seedat</p><p><strong>39. Neurological soft skins in Nigerian Africans with first episode schizophrenia: Factor structure and clinical correlates</strong></p><p><strong></strong>A Ojagbemi, O Esan, O Gureje, R Emsley</p><p><strong>40. Should psychiatric patients know their MTHFR status?</strong></p><p>E Peter</p><p><strong>41. Clinical and functional outcome of treatment refractory first-episode schizophrenia</strong></p><p>L Phahladira, R Emsley, L Asmal, B Chiliza</p><p><strong>42. Bioethics by case discussion</strong></p><p>W Pienaar</p><p><strong>43. Reviewing our social contract pertaining to psychiatric research in children, research in developing countries and distributive justice in pharmacy</strong></p><p>W Pienaar</p><p><strong>44. The performance of the MMSE in a heterogenous elderly South African population</strong></p><p>S Ramlall, J Chipps, A I Bhigjee, B J Pillay</p><p><strong>45. Biological basis addiction (alocohol and drug addiction)</strong></p><p>S Rataemane</p><p><strong>46. Volumetric brain changes in prenatal methamphetamine-exposed children compared with healthy unexposed controls</strong></p><p><strong></strong>A Roos, K Donald, G Jones, D J Stein</p><p><strong>47. Single voxel proton magnetic resonance spectroscopy of the amygdala in social anxiety disorder in the context of early developmental trauma</strong></p><p>D Rosenstein, A Hess, S Seedat, E Meintjies</p><p><strong>48. Discussion of HDAC inhibitors, with specific reference to supliride and its use during breastfeeding</strong></p><p>J Roux</p><p><strong>49. Prevalence and clinical correlates of police contact prior to a first diagnosis of schizophrenia</strong></p><p>C Schumann, L Asmal, K Cloete, B Chiliza, R Emsley</p><p><strong>50. Are dreams meaningless?</strong></p><p>M Solms</p><p><strong>51. The conscious id</strong></p><p>M Solms<strong></strong></p><p><strong>52. Depression and resilience in HIV-infected women with early life stress: Does trauma play a mediating role?</strong></p><p>G Spies, S Seedat</p><p><strong>53. State of affairs analysis for forensic psychiatry in SA</strong></p><p>U Subramaney</p><p><strong>54. Escitalopram in the prevention of post-traumatic stress disorder: A pilot randomised controlled trial</strong></p><p>S Suliman, S Seedat, J Pingo, T Sutherland, J Zohar, D J Stein</p><p><strong>55. Epigenetic consequences of adverse early social experiences in primates</strong></p><p>S Suomi</p><p><strong>56. Risk, resilience, and gene x environment interactions in primates</strong></p><p>S Suomi</p><p><strong>57. Biological aspects of anorexia nervosa</strong></p><p>C Szabo</p><p><strong>58. Agents used and profiles of non-fatal suicidal behaviour in East London</strong></p><p>H Uys</p><p><strong>59. The contributions of G-protein coupled receptor signalling to opioid dependence</strong></p><p>J van Tonder</p><p><strong>60. Emerging trend and innovation in PTSD and OCD</strong></p><p>J Zohar</p><p><strong>61. Making the SASOP treatment guidelines operational</strong></p><p>E Allers</p><p><strong>Poster Presentations</strong></p><p><strong>62. Neuropsychological deficits in social anxiety disorder in the context of early developmental trauma</strong></p><p><strong></strong>S Bakelaar, D Rosenstein, S Seedat</p><p><strong>63.Social anxiety disorder in patients with or without early childhood trauma: Relationship to behavioral inhibition and activation and quality of life</strong></p><p><strong></strong>S Bakelaar, C Bruijnen, A Sambeth, S Seedat</p><p><strong>64. Exploring altered affective processing in obssessive compulsive disorder symptom subtypes</strong></p><p>E Breet, J Ipser, D Stein, C Lochner<strong><br /></strong></p><p><strong>65. To investigate the bias toward recognising the facial expression of disgust in obsessive compulsive disorder as well as the effect of escitalopram</strong></p><p>E Breet, J Ipser, D Stein, C Lochner</p><p><strong>66. A fatal-case of nevirapine-induced Stevens-Johnson's syndrome in HIV mania</strong></p><p>A Bronkhorst, Z Zingela, W M Qwesha, B P Magigaba<strong></strong></p><p><strong>67. Association of the COMT G472A (met/met) genotype with lower disability in people diagnosed with multiple sclerosis</strong></p><p>W Davis, S J van Rensburg, L Fisher, F J Cronje, D Geiger, M J Kotze</p><p><strong>68. Homocycsteine levels are associated with the fat mass and obesity associated gene FTO(intron 1 T&gt;A) polymorphism in MS patients</strong></p><p>W Davis, S J Van Rensburg, M J Kotze, L Fisher, M Jalali, F J Cronje, K Moremi, J Gamieldien, D Geiger, M Rensburg, R van Toorn, M J de Klerk, G M Hon, T Matsha, S Hassan, R T Erasmus</p><p><strong>69. Analysis of the COMT 472 G&gt;A (rs4680) polymorphism in relation to environmental influences as contributing factors in patients with schizophrenia</strong></p><p>D de Klerk, S J van Rensburg, R A Emsley, D Geiger, M Rensburg, R T Erasmus, M J Kotze</p><p><strong>70. Dietary folate intake, homocysteine levels and MTHFR mutation detection in South African patients with depression: Test development for clinical application </strong></p><p>D Delport, N vand der Merwe, R Schoeman, M J Kotze</p><p><strong>71. The use ofexome sequencing for antipsychotic pharmacogenomic applications in South African schizophrenia patients</strong></p><p>B Drogmoller, D Niehaus, G Wright, B Chiliza, L Asmal, R Emsley, L Warnich</p><p><strong>72. The effects of HIV on the ventral-striatal reward system</strong></p><p>S du Plessis, M Vink, J Joska, E Koutsilieri, C Scheller, B Spottiswoode, D Stein, R Emsley</p><p><strong>73. Xenomelia relates to asymmetrical insular activity: A case study of fMRI</strong></p><p>S du Plessis, M Vink, L Asmal</p><p><strong>74. Maternal mental helath: A prospective naturalistic study of the outcome of pregancy in women with major psychiatric disorders in an African country</strong></p><p>E du Toit, L Koen, D Niehaus, B Vythilingum, E Jordaan, J Leppanen</p><p><strong>75. Prefrontal cortical thinning and subcortical volume decrease in HIV-positive children with encephalopathy</strong></p><p>J P Fouche, B Spottiswoode, K Donald, D Stein, J Hoare</p><p><strong>76. H-magnetic resonance spectroscopy metabolites in schizophrenia</strong></p><p>F Howells, J Hsieh, H Temmingh, D J Stein</p><p><strong>77. Hypothesis for the development of persistent methamphetamine-induced psychosis</strong></p><p><strong></strong> J Hsieh, D J Stein, F M Howells</p><p><strong>78. Culture, religion, spirituality and psychiatric practice: The SASOP Spirituality and Psychiatry Special Interest Group Action Plan for 2012-2014</strong></p><p>B Janse van Rensburg</p><p><strong>79. Cocaine reduces the efficiency of dopamine uptake in a rodent model of attention-deficit/hyperactivity disorder: An <em>in vivo</em> electrochemical study</strong></p><p><strong></strong>L Kellaway, J S Womersley, D J Stein, G A Gerhardt, V A Russell</p><p><strong>80. Kleine-Levin syndrome: Case in an adolescent psychiatric unit</strong></p><p>A Lachman</p><p><strong>81. Increased inflammatory stress specific clinical, lifestyle and therapeutic variables in patients receiving treatment for stress, anxiety or depressive symptoms</strong></p><p>H Luckhoff, M Kotze, S Janse van Rensburg, D Geiger</p><p><strong>82. Catatonia: An eight-case series report</strong></p><p>M Mabenge, Z Zingela, S van Wyk</p><p><strong>83. Relationship between anxiety sensitivity and childhood trauma in a random sample of adolescents from secondary schools in Cape Town</strong></p><p>L Martin, M Viljoen, S Seedat</p><p><strong>84. 'Making ethics real'. An overview of an ethics course presented by Fraser Health Ethics Services, BC, Canada</strong></p><p>JJ McCallaghan</p><p><strong>85. Clozapine discontinuation rates in a public healthcare setting</strong></p><p>M Moolman, W Esterhuysen, R Joubert, J C Lamprecht, M S Lubbe</p><p><strong>86. Retrospective review of clozapine monitoring in a publica sector psychiatric hospital and associated clinics</strong></p><p>M Moolman, W Esterhuysen, R Joubert, J C Lamprecht, M S Lubbe</p><p><strong>87. Association of an iron-related TMPRSS6 genetic variant c.2007 C&gt;7 (rs855791) with functional iron deficiency and its effect on multiple sclerosis risk in the South African population</strong></p><p>K Moremi, S J van Rensburg, L R Fisher, W Davis, F J Cronje, M Jalali Sefid Dashti, J Gamieldien, D Geiger, M Rensburg, R van Toorn, M J de Klerk, G M Hon, T Matsha, S Hassan, R T Erasmus, M Kidd, M J Kotze</p><p><strong>88. Identifying molecular mechanisms of apormophine-induced addictive behaviours</strong></p><p>Z Ndlazi, W Daniels, M Mabandla</p><p><strong>89. Effects of lifestyle factors and biochemistry on the major neck blood vessels in patients with mutiple sclerosis</strong></p><p>M Nelson, S J van Rensburg, M J Kotze, F Isaacs, S Hassan</p><p><strong>90. Nicotine protects against dopamine neurodegenration and improves motor deficits in a Parkinsonian rat model</strong></p><p>N Ngema, P Ngema, M Mabandla, W Daniels</p><p><strong>91. Cognition: Probing anatomical substrates</strong></p><p>H Nowbath</p><p><strong>92. Chronic exposure to light reverses the effects of maternal separation on the rat prefrontal cortex</strong></p><p>V Russel, J Dimatelis</p><p><strong>93. Evaluating a new drug to combat Alzheimer's disease</strong></p><p>S Sibiya, W M U Daniels, M V Mabandla</p><p><strong>94. Structural brain changes in HIV-infected women with and without childhood trauma</strong></p><p>G Spies, F Ahmed, C Fennema-Notestine, S Archibald, S Seedat</p><p><strong>95. Nicotine-stimulated release of hippocampal norepinephrine is reduced in an animal model of attention-deficit/ hyperactivity disorder: the spontaneously hypertensive rat</strong></p><p>T Sterley</p><p><strong>96. Brain-derive neurotrophic factor (BDNF) protein levels in anxiety disorders: Systematic review and meta-regression analysis</strong></p><p>S Suliman, S M J Hemmings, S Seedat</p><p><strong>97. A 12-month retrospective audit of the demographic and clinical profile of mental healthcare users admitted to a district level hospital in the Western Cape, South Africa</strong></p><p>E Thomas, K J Cloete, M Kidd, H Lategan</p><p><strong>98. Magnesium recurarization: A comparison between reversal of neuromuscular block with sugammadex v. neostigmine/ glycopyrrolate in an <em>in vivo</em> rat model</strong></p><p><strong></strong>M van den Berg, M F M James, L A Kellaway</p><p><strong>99. Identification of breast cancer patients at increased risk of 'chemobrain': Case study and review of the literature</strong></p><p>N van der Merwe, R Pienaar, S J van Rensburg, J Bezuidenhout, M J Kotze</p><p><strong>100. The protective role of HAART and NAZA in HIV Tat protein-induced hippocampal cell death</strong></p><p>S Zulu, W M U Daniels, M V Mabandla</p>

This thesis investigates the use of newly-developed survival analysis tools for credit scoring. Credit scoring techniques are currently used by financial institutions to estimate the probability of a customer defaulting on a loan by a predetermined time in the future. While a number of classification techniques are currently used, banks are now becoming more concerned with estimating the lifetime of the loan rather than just the probability of default. Difficulties arise when using standard statistical techniques due to the presence of censoring in the data. Survival analysis, originating from medical and engineering fields, is an area of statistics that typically deals with censored lifetime data. The theoretical developments in this thesis revolve around linear regression for censored data, in particular the Buckley-James method. The Buckley-James method is analogous to linear regression and gives estimates of the mean expected lifetime given a set of explanato ry variables. The first development is a measure of fit for censored regression, similar to the classical r-squared of linear regression. Next, the variable-reduction technique of stepwise selection is extended to the Buckley-James method. For the last development, the Buckley-James algorithm is altered to incorporate non-linear regression methods such as neural networks and Multivariate Adaptive Regression Splines (MARS). MARS shows promise in terms of predictive power and interpretability in both simulation and empirical studies. The practical section of the thesis involves using the new techniques to predict the time to default and time to repayment of unsecured personal loans from a database obtained from a major Australian bank. The analyses are unique, being the first published work on applying Buckley-James and related methods to a large-scale financial database.