Association of mental health with health care use and cost: a population study.

Objective: To compare the health costs of groups with and without psychiatric diagnoses (PDs) using 9 years of physician billing data.

Methods: A dataset containing registration data for all patients receiving public mental health service was constructed and subsequently matched, on age and sex, in a final patient to comparison patient ratio of 1:8, with health care users who did not receive treatment in the mental health system. Three groups emerged: a patient PD group-patients with psychiatric disorders treated in public mental health care (n = 76 677); a comparison patient PD group-comparison patients with PDs treated in physicians only (n = 277 627); and a patient- comparison patient non-PD group-patients (treated in specialized publicly funded care or by their physician) without PDs (n = 329 177). Examining over 42 million billing records for all of these patients, we compared the average number of visits and the average health only (nonpsychiatric) billing cost per each patient during the 9-year study period across the groups.

Results: Among all health care users in the data, the health costs (Total Costs - Mental Health Costs) were greater on average for the patients with PD group ($3437) and the comparison patient PD group ($3265), compared with patient-comparison patient non-PD group ($1345). Forty-six percent of the comparison sample had a PD.

Conclusions: Having a mental health problem is related to greater health-related expenditures. This has important policy implications on how mental health resources are constructed and rationed within the health care system.