Health service and medication costs associated with common mental disorders and subthreshold symptoms in women: Findings from the Geelong Osteoporosis Study in Australia

Objective: This analysis estimated 2013 annual healthcare costs associated with the common mental disorders of mood and anxiety disorders and psychological symptoms within a representative sample of Australian women. Methods: Data from the 15-year follow-up of women in the Geelong Osteoporosis Study were linked to 12-month Medicare Benefits Schedule and Pharmaceutical Benefits Scheme data. A Structured Clinical Interview for Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Non-patient edition identified common mental disorders and the General Health Questionnaire 12 assessed psychological symptoms. Participants were categorised into mutually exclusive groups: (1) common mental disorder (past 12 months), (2) subthreshold (no common mental disorder and General Health Questionnaire 12 score ⩾4) or (3) no common mental disorder and General Health Questionnaire 12 score <4. Two-part and hurdle models estimated differences in service use, and adjusted generalised linear models estimated mean differences in costs between groups. Results: Compared to no common mental disorder, women with common mental disorders utilised more Medicare Benefits Schedule services (mean 26.9 vs 20.0, p < 0.001), had higher total Medicare Benefits Schedule cost ($1889 vs $1305, p < 0.01), received more Pharmaceutical Benefits Scheme prescriptions (35.8 vs 20.6, p < 0.001), had higher total Pharmaceutical Benefits Scheme cost ($1226 vs $740, p < 0.05) and had significantly higher annual out-of-pocket costs for Pharmaceutical Benefits Scheme prescriptions ($249 vs $162, p < 0.001). Compared to no common mental disorder, subthreshold women were less likely to use any Medicare Benefits Schedule service (89.6% vs 97.0%, p < 0.01), but more likely to use mental health services (11.4% vs 2.9%, p < 0.01). The subthreshold group received more Pharmaceutical Benefits Scheme prescriptions (mean 43.3 vs 20.6, p < 0.001) and incurred higher total Pharmaceutical Benefits Scheme cost ($1268 vs $740, p <.05) compared to no common mental disorder. Conclusions: Common mental disorders and subthreshold psychological symptoms place a substantial economic burden on Australian healthcare services and consumers.