title: A diagnostic model incorporating P50 sensory gating and neuropsychological tests for schizophrenia.
abstract: OBJECTIVE
  Endophenotypes in schizophrenia research is a contemporary approach to studying this heterogeneous mental illness, and several candidate neurophysiological markers (e.g. P50 sensory gating) and neuropsychological tests (e.g. Continuous Performance Test (CPT) and Wisconsin Card Sorting Test (WCST)) have been proposed. However, the clinical utility of a single marker appears to be limited. In the present study, we aimed to construct a diagnostic model incorporating P50 sensory gating with other neuropsychological tests in order to improve the clinical utility.
  
  
  METHODS
  We recruited clinically stable outpatients meeting DSM-IV criteria of schizophrenia and age- and gender-matched healthy controls. Participants underwent P50 sensory gating experimental sessions and batteries of neuropsychological tests, including CPT, WCST and Wechsler Adult Intelligence Scale Third Edition (WAIS-III).
  
  
  RESULTS
  A total of 106 schizophrenia patients and 74 healthy controls were enrolled. Compared with healthy controls, the patient group had significantly a larger S2 amplitude, and thus poorer P50 gating ratio (gating ratio = S2/S1). In addition, schizophrenia patients had a poorer performance on neuropsychological tests. We then developed a diagnostic model by using multivariable logistic regression analysis to differentiate patients from healthy controls. The final model included the following covariates: abnormal P50 gating (defined as P50 gating ratio >0.4), three subscales derived from the WAIS-III (Arithmetic, Block Design, and Performance IQ), sensitivity index from CPT and smoking status. This model had an adequate accuracy (concordant percentage = 90.4%; c-statistic = 0.904; Hosmer-Lemeshow Goodness-of-Fit Test, p = 0.64>0.05).
  
  
  CONCLUSIONS
  To the best of our knowledge, this is the largest study to date using P50 sensory gating in subjects of Chinese ethnicity and the first to use P50 sensory gating along with other neuropsychological tests to develop a diagnostic model for schizophrenia. Further research to validate the predictive accuracy of this model by applying it on other samples is warranted.
authors: Department of Psychiatry, Cathay General Hospital, Taipei, Taiwan.
authors: Jia-Chi
authors: JC
authors: Shan
authors: Chih-Min
authors: CM
authors: Liu
authors: Ming-Jang
authors: MJ
authors: Chiu
authors: Chen-Chung
authors: CC
authors: Liu
authors: Yi-Ling
authors: YL
authors: Chien
authors: Tzung-Jeng
authors: TJ
authors: Hwang
authors: Yi-Ting
authors: YT
authors: Lin
authors: Ming H
authors: MH
authors: Hsieh
authors: Fu-Shan
authors: FS
authors: Jaw
authors: Hai-Gwo
authors: HG
authors: Hwu
mesh_terms: D000328:Adult; D016022:Case-Control Studies; D003710:Demography; D005260:Female; D006801:Humans; D016015:Logistic Models; D008297:Male; D008954:Models, Biological; D015999:Multivariate Analysis; D009483:Neuropsychological Tests; D012559:Schizophrenia / Q000175:diagnosis* / Q000503:physiopathology*; D012565:Schizophrenic Psychology; D055139:Sensory Gating / Q000502:physiology*