Abstract
Background: Mental, Neurological and Substance-related disorders are a significant contributor to the global burden of disease. The availability of screening instruments in the local language would improve identification of these cases.
Aim: In this study, we investigated the reliability and validity of the adapted Efik version of the 12-item General Health Questionnaire.
Methods: This was a descriptive, cross-sectional study involving 426 respondents aged 18-65years, recruited from attendees of the General Out-patient Clinic (GOPC) of the University of Calabar Teaching Hospital using convenience sampling technique. The English version of the 12-item GHQ was translated into an adapted Efik version using standard guidelines, and both versions were administered on study participants. Respondents with a score of 3 and above (cases) and 10% of noncases were interviewed using the Mini International Neuropsychiatric Interview (MINI-6.00). Data was analyzed using the Statistical Package for Social Sciences Version 22. Reliability and validity coefficients were generated using a 2x2 contingency table.
Results: The internal consistency using the Cronbach's alpha coefficient was 0.87. ROC analysis showed that a cut-off point of 3 gave the best balance of sensitivity and specificity (0.89 and 0.88 respectively), the highest Youden's index (0.77), Positive Predictive Value (PPV) of 0.69, Negative Predictive Value (NPV) of 0.96, OFC of 0.88 and a misclassification rate of 0.12.
Conclusion: The results suggest that the adapted Efik version of the 12-item GHQ at a cut-off point of 3 is a reliable, sensitive, and valid screening instrument.

Key words: GHQ-12 (Efik), Internal consistency, Reliability, Validity