Background: In order to estimate the health needs of cultural groups, the cross-cultural validity of instruments requires investigation in distinct cultural rather than ethnic or racial groups.
Method: We screened 'Punjabi' and 'English' primary care attenders in South London (UK), using the General Health Questionnaire (GHQ-12), an English origin instrument, and the Amritsar Depression Inventory (ADI), which was developed in the Punjab in India. The criterion measure was the Clinical Interview Schedule (CIS-R). We calculated the validity coefficients, optimal thresholds and the area under the 'Receive Operating Characteristic' curve to compare cross-cultural performance. We identified items on each questionnaire that contribute to performance of the instruments.
Results: The GHQ-12 has high validity coefficients in both cultural groups. The ADI performs as well amongst English subjects, but among Punjabis it is poorer than the GHQ-12. Among Punjabis who have been resident in the UK for over 30 years, the ADI performs no better than chance. Few items on the ADI or the GHQ are strongly predictive of case status.
Conclusions: The GHQ-12 shows good validity in both cultures. Expressions of distress may change due to acculturation. 'Culturally sensitive' screening instruments need to reflect this. Further work might attend to the changing expressions of distress following migration.