Comparing Preventable Hospitalizations Among Veterans With and Without Mental Illnesses Before and After Implementation of PACT.

Objectives: The authors examined whether the rate of preventable hospitalizations among veterans with mental illness changed after implementation of the Department of Veterans Affairs (VA) primary care medical home-Patient Aligned Care Teams (PACT).

Methods: A 12-year retrospective cohort analysis was conducted of data from 9,206,017 veterans seen in 942 VA primary care clinics between October 2003 and March 2015. Preventable hospitalizations were those related to ambulatory care-sensitive conditions (ACSCs), identified with ICD-9 codes. Changes in rates of ACSC-related hospitalizations were compared between patients with and without mental illness in two age groups (<65, ≥65). Patients with mental illness diagnoses were grouped as follows: depression, posttraumatic stress disorder, anxiety, substance use disorder, and serious mental illness. Interrupted time-series analysis was used to model long-term trends and detect deviations after PACT implementation.

Results: There was an overall increase in mental illness diagnoses across both age groups. Among older veterans (≥65) with any mental illness, the rate (per 1,000 patients) of ACSC-related hospitalizations was five fewer in the post-PACT period, compared with the pre-PACT period. Among younger veterans (<65), there was a slight increase in ACSC-related hospitalizations in years 3-5 post-PACT if they had any mental illness (.6 per 1,000 patients), depression (.3), anxiety (1.4), or a substance use disorder (.6).

Conclusions: In this retrospective, observational study examining large systemwide changes in clinical practice, mental illness was more likely to be diagnosed after PACT implementation, compared with before, and results suggested a benefit of PACT implementation among older veterans in terms of a reduction in ACSC-related hospitalizations.