RESUMO
Objective: To compare the sensitivity, specificity and reliability between the Malay GHQ-30 and the Malay GHQ-12 in detecting distressed medical students. This study determined which version is more sensitive, specific and reliable in detecting distressed medical students. Methods: Three validated instruments, the Malay version GHQ-30, the Malay version GHQ-12 and the Malay version Beck Depression Inventory-II (BDI-II), were administered to a total of 187 medical students. Distress diagnoses were made based on the Malay version BDI-II. ROC curve analysis was applied to determine the sensitivity and specificity of the both GHQs by testing against the BDI-II. Reliability analysis (Cronbach’s alpha) was applied to test internal consistency of the GHQ. The analysis was done using SPSS version 12. Results: 141 (75.4%) medical students participated in this study. The GHQ-30 sensitivity and specificity at cut-off point of 6 was 87.5% and 80.6% respectively with positive predictive value (PPV) of 70% as well as area under ROC curve was 0.93. The GHQ-12 sensitivity and specificity at cut-off point of 4 was 81.3% and 75.3% respectively with PPV of 62.9% as well as area under ROC curve was 0.82 The Cronbach’s alpha value of the GHQ-30 and GHQ-12 was 0.93 and 0.85 respectively. The Kappa value for the GHQ- 12 and GHQ-30 was 0.65 (p < 0.001). Conclusion: This study showed the Malay GHQ-30 had better ability to discriminate between distressed and non-distressed medical students compared to the Malay GHQ-12. The shorter version was found to be as reliable as the long version GHQ-30 in detecting distressed medical students. The optimum threshold score for the GHQ-30 and GHQ-12 to detect distressed medical students were 6 and 4 respectively. The GHQ-12 and GHQ-30 showed a good level of agreement in detecting distressed medical students.
RESUMO
Objective: To determine the sensitivity, specificity and internal consistency of the Malay version GHQ-12 among medical student population. This study determined the appropriate GHQ-12 score to detect distressed medical students. Methods: The Malay version of GHQ-12 was derived based on two sources which were the original version GHQ-12 and the validated Malay version 30-items GHQ. The GHQ-12 and the Malay version Beck Depression Inventory-II (BDI-II) were administered to a total of 141 medical students. Distress diagnoses were made based on the Malay version BDI-II. ROC curve analysis was applied to determine the sensitivity and specificity of the GHQ-12 by testing against the BDI-II. Reliability analysis (Cronbach’s alpha and item total correlation) was applied to test internal consistency of the GHQ-12. The analysis was done using SPSS version 12.Results: The GHQ-12 sensitivity and specificity at cut-off point of 3/4 was 81.3% and 75.3% respectively with positive predictive value (PPV) of 62.9% as well as area under ROC curve more than 0.7. The Cronbach’s alpha value of the GHQ-12 was 0.85.Conclusion: This study showed the Malay version GHQ-12 is a valid and reliable screening tool in detecting distressed medical students. The GHQ-12 score equal to or more than 4 was considered as significant distress.