Impact of the ICD-10 Primary Health Care (PHC) diagnostic and management guidelines for mental disorders on detection and outcome in primary care. Cluster randomised controlled trial.

BACKGROUND: The World Health Organization (WHO) ICD-10 Primary Health Care (PHC) Guidelines for Diagnosis and Management of Mental Disorders (1996) have not been evaluated in a pragmatic randomised controlled trial (RCT). AIMS: To evaluate the effect of local adaptation and dissemination of the guidelines. METHOD: Pragmatic, pair-matched, cluster RCT involving 30 practices. RESULTS: Guideline practices were less sensitive but more specific in identifying morbidity, but these differences were not significant. Guideline patients did not differ from usual-care patients on 12-item General Health Questionnaire scores at 3-month follow-up or in the proportion who were still cases. There were no significant differences in secondary outcomes. CONCLUSIONS: Attempts to influence clinician behaviour through a process of adaptation and extension of guidelines are unlikely to change detection rates or outcomes.