Changing Patterns of Mental Health Care Use: The Role of Integrated Mental Health Services in Veteran Affairs Primary Care.

OBJECTIVE: Aiming to foster timely, high-quality mental health care for Veterans, VA's Primary Care-Mental Health Integration (PC-MHI) embeds mental health specialists in primary care and promotes care management for depression. PC-MHI and patient-centered medical home providers work together to provide the bulk of mental health care for primary care patients with low-to-moderate-complexity mental health conditions. This study examines whether increasing primary care clinic engagement in PC-MHI services is associated with changes in patient health care utilization and costs.

METHODS: We performed a retrospective longitudinal cohort study of primary care patients with identified mental health needs in 29 Southern California VA clinics from October 1, 2008 to September 30, 2013, using electronic administrative data (n = 66,638). We calculated clinic PC-MHI engagement as the proportion of patients receiving PC-MHI services among all primary care clinic patients in each year. Capitalizing on variation in PC-MHI engagement across clinics, our multivariable regression models predicted annual patient use of 1) non-primary care based mental health specialty (MHS) visits, 2) total mental health visits (ie, the sum of MHS and PC-MHI visits), and 3) health care utilization and costs. We controlled for year- and clinic-fixed effects, other clinic interventions, and patient characteristics.

RESULTS: Median clinic PC-MHI engagement increased by 8.2 percentage points over 5 years. At any given year, patients treated at a clinic with 1 percentage-point higher PC-MHI engagement was associated with 0.5% more total mental health visits (CI, 0.18% to 0.90%; P = .003) and 1.0% fewer MHS visits (CI, -1.6% to -0.3%; P = .002); this is a substitution rate, at the mean, of 1.5 PC-MHI visits for each MHS visit. There was no PC-MHI effect on other health care utilization and costs.

CONCLUSIONS: As intended, greater clinic engagement in PC-MHI services seems to increase realized accessibility to mental health care for primary care patients, substituting PC-MHI for MHS visits, without increasing acute care use or total costs. Thus, PC-MHI services within primary care clinics may improve mental health care value at the patient population level. More research is needed to understand the relationship between clinic PC-MHI engagement and clinical quality of mental health care.