Factor structure and reliability of the 30-item Sinhala version of General Health Questionnaire (GHQ).

OBJECTIVE: To determine the factor structure and the reliability of the Sinhala version of the General Health Questionnaire-30 (GHQ-30).

METHODS: This was a descriptive study including 368 patients with in the age range of 18-75 years, attending the Out Patient Department (OPD) of Colombo North Teaching Hospital, Ragama, Sri Lanka during the period between June 2009 and September 2010. Sinhala version of GHQ-30 was given to be completed by the participants. Each item of the GHQ was rated on a four-point scale (0-1-2-3). Factor analyses were performed by applying Generalized Least Squares method using oblimin rotation. The internal consistency was assessed by calculating Cronbach's α coefficient.

RESULTS: Median age of the study population was 32.5 years (Inter quartile range [IQR]=21 years) and the median GHQ score was 9 (IQR 7). GHQ-30 produced a five factor solution which accounted for 51.6% of the total variance (TV). Factor I (Depression) accounted for 38% of TV, Factor II (Loss of confidence) 5%, Factor III (Insomnia) 4%, Factor IV (Social dysfunction) 2.7% and Factor V (Anxiety) 2%. The Cronbach's alpha coefficients of GHQ-30 was 0.94 indicating satisfactory internal consistency.

CONCLUSIONS: GHQ-30 comprises five factors/subscales and it displayed adequate reliability for assessment of psychiatric disorders among Sinhala speaking primary care attendees in Sri Lanka.