Reliability and validity of the General Health Questionnaire (GHQ-12) among urological patients: a Malaysian study.

This present study was undertaken to validate the English version of the General Health Questionnaire (GHQ-12) in urological patients. Validity and reliability were studied in patients with lower urinary tract symptoms (LUTS) and patients without LUTS. Reliability was evaluated using the test-retest method and internal consistency was assessed using Cronbach's alpha. Sensitivity to change was expressed as the effect size in the pre-intervention versus post-intervention score in additional patients with benign prostatic hyperplasia (BPH) who underwent transurethral resection of the prostate (TURP). Internal consistency was excellent. A high degree of internal consistency was observed for each of the 12 items with Cronbach's alpha value of 0.37-0.79, while total scores was 0.79 in the population study. Test-retest correlation coefficient for the 12 items score were highly significant. Intraclass correlation coefficient was high (0.35-0.79). It showed a high degree of sensitivity and specificity to the effects of treatment. A high degree of significant level between baseline and post-treatment scores were observed across all 12 items in the treatment cohort but not in the control group. The GHQ-12 is suitable, reliable, valid and sensitive to clinical change in urological disorders.