Findings of a longitudinal cohort study on depressive disorders in Hong Kong’s primary care

Abstract

Introduction: The primary care setting is the entry point for most people into the health system and primary care physicians are ideally placed to serve as the central service provider for patients with depression. Unfortunately, there are many challenges identifying and managing depression in primary care and long-term outcomes and factors affecting prognosis remain unclear. To make recommendations regarding mental health policy, it is necessary to have a current knowledge of the epidemiology and outcomes of depressive disorders in patients presenting to primary care. Methods A cross-sectional followed by a longitudinal cohort study was conducted. Adult patients recruited from the waiting rooms of 59 primary care doctors completed a questionnaire which screened for depression. Doctors provided clinical information about the patient. Consenting patients were followed up by telephone at 3, 6 and 12 months. Results 10,179 subjects were recruited at baseline (response rate 81.0%). 4358 subjects entered the longitudinal study (response rate 42.8%). The cross-sectional prevalence of PHQ-screened depression was 10.69%, 12-month incidence was 6.67% and 12-month remission rate was 60.31%. Detection rate by doctors was 23.1%. Over one year, the health –related quality of life scores improved by 10% (SF-12v2 PCS) and 30% (SF-12v2 MCS). Patient-reported medication and primary care service use was increased; however, mental health service use was low. The most common patient-reported mental health service used was psychiatrists; the most common referral service used by doctors was for counselling. Conclusions Most cases of depression encountered in primary care are mild and self-limiting, but associated with significant impairment to health-related quality of life. Diagnosis of depression by a doctor does not appear to have any significant effect on resolution of symptoms and quality of life after 1 year but is associated with greater improvements in mental health-related quality of life.