Assessing the effect of the VHA PCMH model on utilization patterns among veterans with PTSD

The Veterans Health Administration (VHA) implemented a patient-centered medical home (PCMH)-based Patient Aligned Care Teams (PACT) model in 2010. We examined its effects on the utilization of health services among US veterans with posttraumatic stress disorder (PTSD).

We analyzed VHA clinical and administrative data to conduct an interrupted time series study. Encounter-level data were obtained for the period of April 1, 2005, through March 31, 2014. We identified 642,660 veterans with PTSD who were assigned to either a high- or low-PCMH implementation group using a validated VHA PCMH measurement instrument.

We measured the effect of high-PCMH implementation on the count of hospitalizations and primary care, specialty care, specialty mental health, emergency department (ED), and urgent care encounters compared with low-PCMH implementation. We fit a multilevel, mixed-effects, negative binomial regression model and estimated average marginal effects and incidence rate ratios.

Compared with patients in low-PCMH implementation clinics, patients who received care in high-PCMH implementation clinics experienced a decrease in hospitalizations (incremental effect [IE], -0.036; 95% confidence interval [CI], -0.0371 to -0.0342), a decrease in specialty mental health encounters (IE, -0.009; 95% CI, -0.009 to -0.008), a decrease in urgent care encounters (IE, -0.210; 95% CI, -0.212 to -0.207), and a decrease in ED encounters (IE, -0.056; 95% CI, -0.057 to -0.054).

High PCMH implementation positively affected utilization patterns by reducing downstream use of high-cost inpatient and specialty services. Future research should investigate whether a reduction in utilization of health services indeed results in higher levels of virtual and non-face-to-face access, or if the PACT model has reduced necessary access to care.