Validity and Reliability of WHO Schedules for Clinical Assessment in Neuropsychiatry (SCAN)-Thai Version: Cognitive Impairment or Decline Section
Nawanant Piyavhatkul MD*, Thawatchai Krisanaprakornkit MD*, Suchat Paholpak MD*, Jiraporn Khiewyou PhD**
Affiliation : * Department of Psychiatry, Faculty of Medicine, Khon Kaen University, Khon Kaen ** Department of Biostatistics and Demography, Faculty of Public Health, Khon Kaen University, Khon Kaen
Objective : To determine the validity and reliability of the Thai version of the Cognitive Impairment or Decline
section of WHO Schedules for Clinical Assessment in Neuropsychiatry (SCAN) version 2.1.
Material and Method: The SCAN interview version 2.1 Cognitive Impairment or Decline Section was trans-
lated into Thai and its content validity tested by back translation. Psychiatrists competent in the use of the
schedules and aware of their underlying objectives tested the linguistic clarity of the psychiatric schedules for
Thais from the country’s four regions. The reliability of SCAN: Cognitive Impairment or Decline Section was
tested between June and November 2005 on 30 participants, including 15 patients with cognitive impairment
and 15 normal volunteers.
Results : Based on reactions from Thais and consultations from competent psychiatrists, content validity was
indeed established. The duration of interviews for the Cognitive Impairment or Decline Section averaged
48.99 min (59.71 for patients with cognitive impairment and 33.77 for normal subjects). The respective mean
inter- and intra-rater reliability kappa was 0.72 (SD = 0.31) and 0.78 (SD = 0.23). The reliability of the
majority of items reached a substantial to almost perfect level; however, three items (3.66%) had poor and nine
(6.67%) only slight inter-rater agreement. Some items needed clarification of the scoring method. The respective
inter- and intra-rater reliability of the continuous data was 0.93 and 0.96.
Conclusion : The Cognitive Impairment or Decline Section of the WHO Schedules for Clinical Assessment in
Neuropsychiatry (SCAN Thai Version) is demonstrably an effective tool for diagnosing cognitive impairment
disorders among Thais.
Keywords : Schedules for clinical assessment in neuropsychiatry, Reliability study, Validity study, Semi-structured interview schedules, Dementia, Alzheimer’s, Multi-infarct dementia, Organic personality disorder, Mild cognitive disorder
