Background: The General Health Questionnaire (GHQ) is a widely used instrument to detect non potential psychotic psychological problems. The Sinhala translation of GHQ-30 has been widely used for research purposes in Sri Lanka, but details pertaining to the validation procedure have not been published. Objective: To determine the criterion validity of Sinhala versions of GHQ-30.
Methods: This was a descriptive cross-sectional study including 374 patients aged 18 to 75 years, attending Out Patient Department of Colombo North Teaching Hospital between June 2009 to September 2010. Self administered Sinhala version of GHQ-30 was completed by the participants. Clinical Examination was done blindly to the GHQ score by a Psychiatrist based on ICD 10 classification of Depression/Anxiety/social dysfunction as reference standard. Cutoff values for GHQ-30 was determined by applying Receiver Operation Characteristic (ROC) curves.
Results: Optimal cutoff levels were 5/6 for GHQ-30 with a sensitivity of 67.5% (95%CI: 59%– 76%) and a specificity of 80% (95%CI: 75%–85%). Optimal cutoff levels were not changed by sex, age and educational levels. The area under the ROC curve for GHQ-30 was 0.79. Despite above, multilevel likelihood ratios of >1 were obtained only for total scores of ≥7 for GHQ-30.
Conclusions: GHQ 30 displays adequate validity for use in the Sinhala speaking primary care setting attendees for assessing psychiatric disorders.