Service intensity of community mental health outreach among people with untreated mental health problems in Japan: A retrospective cohort study.

Aim: This study aimed to clarify the association between treatment status (untreated or treated) at the start of community mental health outreach services and service intensity.

Methods: This retrospective cohort study was conducted using the Tokorozawa City mental health outreach service users' data. Treatment status at the start of service (exposure variable) and the service intensity (outcome variables) were taken from clinical records. Poisson regression and linear regression analyses were conducted. The frequency of medical or social service use 12 months after service initiation was also calculated. This study was approved by the Research Ethics Committee at the National Center of Neurology and Psychiatry (No. A2020-081).

Results: Of 89 people, 37 (42%) were untreated. Family members in the untreated group were more likely to be targets or recipients of services than in the treated group (b = 0.707, p < 0.001, Bonferroni-adjusted p < 0.001). Compared to the treated group, the untreated group received fewer services themselves (b = -0.290, p = 0.005), and also fewer services by telephone (b = -0.252, p = 0.012); by contrast, they received more services at the health center (b = 0.478, p = 0.031) and for family support (b = 0.720, p = 0.024), but these significant differences disappeared after Bonferroni adjustment. At least 11% of people in the untreated group were hospitalized and 35% were outpatients 12 months after service initiation.

Conclusion: Family involvement may be a key service component for untreated people. The service intensity with and without treatment may vary by service location.