Of the five screening questionnaires, two of which (the K10 and K6) shared six items, most were either already available in local languages (such as the GHQ-12) or in another Indian language (e.g. the K10). Those not available in local languages were translated using the standard, stepwise, method of translation (Sartorius & Kuyken, 1994 ). All questionnaires were piloted to assess feasibility issues, for example on the scoring method. The time duration for reporting complaints varies from 2 weeks in the GHQ-12 to 30 days for the K6/K10. The questionnaires were modified to make them more feasible for use in busy clinics (the GHQ-12 and K10/K6 scoring was made dichotomous) and the duration of reporting symptoms standardized to 2 weeks for all symptoms (as the ICD-10 diagnosis was based on a 2-week duration of symptoms).
The reference standard diagnostic interview was the Revised Clinical Interview Schedule (CIS-R), a structured interview for use by lay interviewers for the measurement and diagnosis of CMD in community and primary-care settings (Lewis et al. 1992 (link)). The CIS-R inquires about the experience of symptoms of CMD in 14 domains (e.g. fatigue, depression, panic). It generates a total score that provides a dimensional measure of CMD. Data can also be analysed using the Programmable Questionnaire System (PROQSY) software program (available from Professor G. Lewis, University of Bristol), which generates ICD-10 diagnoses for the following CMDs: depressive episode, phobias, generalized anxiety disorder, panic disorder, obsessive-compulsive disorders, and mixed anxiety-depression disorder. The CIS-R has been used extensively in India, and specifically in Goa (Sen & Williams, 1987 (link); Patel et al. 1998a (link), b (link), 2003 (link), 2006 (link)). The translation and field testing of the CIS-R in earlier studies in Goa are reported elsewhere (Patel et al. 1998b (link)). We used four case criteria derived from the CIS-R: an ICD-10 diagnosis of any CMD; an ICD-10 diagnosis of depressive episode; a cut-off score of 11/12 (i.e. a score of 12 or more signifying case-level morbidity); and a cut-off score of 17/18 as an indicator of ‘severe’ morbidity.