title: The continuous performance test, identical pairs: norms, reliability and performance in healthy controls and patients with schizophrenia in Singapore.
abstract: OBJECTIVE
  To provide normative values for the healthy ethnic Chinese Singaporean population and a large sample of patients with schizophrenia for the Continuous Performance Task-Identical Pairs (CPT-IP). Participants Data were collected on 1011 healthy ethnic Chinese and 654 patients diagnosed with schizophrenia, all between 21 and 55 years of age.
  
  
  METHODS
  Data were stratified by age and gender. The effects of age, gender and education were explored in patients and controls. Performance indices were assessed in their ability to predict group inclusion. Controls' performance was compared with that reported in a US sample.
  
  
  RESULTS
  Performance was affected by age, sex, and education, with youth, male sex and higher education providing a performance advantage. Patients' performance was lower than controls' by more than 1 standard deviation, with the 3-digit d' score most significantly discriminating between controls and patients. The effects of socio-demographic factors on performance were in line with those conducted in the US and previously reported in the literature.
  
  
  CONCLUSIONS
  This is the largest norming study ever conducted on the CPT-IP. It will enable investigators and clinicians to select appropriate indices to assess severity of cognitive decline and/or evaluate cognitive remediation therapy outcomes after taking into account age, gender and education factors.
authors.affiliation: Research Division, Institute of Mental Health, Singapore; Neuroscience & Behavioral Disorders, Duke-National University of Singapore Graduate Medical School, Singapore.
authors.forename: Attilio
authors.initials: A
authors.lastname: Rapisarda
authors.affiliation: Department of Psychiatry & Behavioral Sciences, Duke University Medical Center.
authors.forename: Michael
authors.initials: M
authors.lastname: Kraus
authors.affiliation: Research Division, Institute of Mental Health, Singapore.
authors.forename: Yi Wen
authors.initials: YW
authors.lastname: Tan
authors.affiliation: Research Division, Institute of Mental Health, Singapore.
authors.forename: Max
authors.initials: M
authors.lastname: Lam
authors.affiliation: Research Division, Institute of Mental Health, Singapore.
authors.forename: Goi Khia
authors.initials: GK
authors.lastname: Eng
authors.affiliation: Research Division, Institute of Mental Health, Singapore; Department of General Psychiatry 1, Institute of Mental Health, Singapore; Office of Clinical Sciences, Duke-NUS Graduate Medical School, National University of Singapore, Singapore.
authors.forename: Jimmy
authors.initials: J
authors.lastname: Lee
authors.affiliation: Research Division, Institute of Mental Health, Singapore.
authors.forename: Mythily
authors.initials: M
authors.lastname: Subramaniam
authors.affiliation: Neuroscience & Behavioral Disorders, Duke-National University of Singapore Graduate Medical School, Singapore.
authors.forename: Simon L
authors.initials: SL
authors.lastname: Collinson
authors.affiliation: Research Division, Institute of Mental Health, Singapore.
authors.forename: Siow Ann
authors.initials: SA
authors.lastname: Chong
authors.affiliation: Neuroscience & Behavioral Disorders, Duke-National University of Singapore Graduate Medical School, Singapore; Department of Psychiatry & Behavioral Sciences, Duke University Medical Center. Electronic address: richard.keefe@duke.edu.
authors.forename: Richard S E
authors.initials: RS
authors.lastname: Keefe
mesh_terms: D000328:Adult; D000367:Age Factors; D001288:Attention; D002681:China / Q000208:ethnology; D003072:Cognition Disorders / Q000175:diagnosis / Q000503:physiopathology; D004522:Educational Status; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D011930:Reaction Time; D012559:Schizophrenia / Q000175:diagnosis* / Q000503:physiopathology; D012565:Schizophrenic Psychology; D012737:Sex Factors; D012846:Singapore; D012959:Socioeconomic Factors; D014481:United States; D055815:Young Adult
keywords: Attention; CPT-IP; Continuous Performance Test; Normative data; Schizophrenia