BACKGROUND: Evidence-based quality improvement (EBQI) methods may facilitate practice redesign for more effective implementation of the patient-centered medical home (PCMH). OBJECTIVE: We assessed changes in health care utilization and costs for patients receiving care from practices using an EBQI approach to implement PCMH and comparison practices over a 5-year period. RESEARCH DESIGN: We used longitudinal, electronic data from patients in 6 practices using EBQI and 28 comparison practices implementing standard PCMH for 1 year before and 4 years after PCMH implementation. We analyzed trends in utilization and costs using bivariate analyses and independent effects of EBQI status on outcomes using multivariate regressions adjusting for year, patient and clinic factors, and patient random effects for repeated measures. SUBJECTS: A total of 136,856 patients using Veterans Affairs primary care. MEASURES: Veterans Affairs ambulatory care encounters, emergency department visits, admissions, and total health care costs per patient. RESULTS: After PCMH implementation, overall utilization for primary care, specialty care, and mental health/substance abuse care decreased, whereas utilization for telephone care increased among all practices. Patients also had fewer hospitalizations and lower costs per patient. In adjusted analyses, EBQI practice was independently associated with fewer primary care (IRR=0.85), specialty care (IRR=0.83), and mental health care encounters (IRR=0.69); these effects attenuated over time (all P<0.01). There was no independent effect of EBQI on prescription drug use, acute care, health care costs, or mortality rate relative to comparison practices. CONCLUSION: EBQI methods enhanced the effects of PCMH implementation by reducing ambulatory care while increasing non-face-to-face care.

Six and one-half million Californians were uninsured for all or some of 2005, a number that is as large as the combined populations of nine other states. The number of uninsured represented one in five children and nonelderly adults, a rate that was slightly lower than in 2003 due to California's tight labor markets and expanding enrollment and retention in California's public coverage programs for children. These marginal improvements are unlikely to continue unabated given the instability of employment-based insurance coverage in the face of rising costs. In this policy brief, we compare insurance coverage over time using the California Health Interview Surveys conducted in 2001, 2003 and 2005. We look at the type of coverage over the past 12 months for both children and nonelederly adults.