Why do we observe a limited impact of primary care access measures on clinical quality indicators?

The study assessed the effects of enhanced primary care access and continuity on clinical quality in a large, multipayer, multispecialty ambulatory care organization with fee-for-service provider incentives. The difference-in-differences estimates indicate that access to own primary care physician is a statistically significant predictor of improved clinical quality, although the effect size is small such that clinical significance may be negligible. Reduced time for own primary care physician appointment and increased enrollment in electronic personal health record are positive predictors of chronic disease management processes and preventive screening but are inconsistently associated with clinical outcomes. Challenges in identifying relationships between access and quality outcomes in a real-world setting are also discussed.