Association of Specialist Physician Payment Model With Visit Frequency, Quality, and Costs of Care for People With Chronic Disease

IMPORTANCE: Specialist physicians are key members of chronic care management teams; to date, however, little is known about the association between specialist payment models and outcomes for patients with chronic diseases. OBJECTIVE: To examine the association of payment model with visit frequency, quality of care, and costs for patients with chronic diseases seen by specialists. DESIGN, SETTING, AND PARTICIPANTS: A retrospective cohort study using propensity-score matching in patients seen by a specialist physician was conducted between April 1, 2011, and September 31, 2014. The study was completed on March 31, 2015, and data analysis was conducted from June 2017 to February 2018 and finalized in August 2019. In a population-based design, 109 839 adults with diabetes or chronic kidney disease newly referred to specialists were included. Because patients seen by independent salary-based and fee-for-service (FFS) specialists were significantly different in observed baseline characteristics, patients were matched 1:1 on demographic, illness, and physician characteristics. EXPOSURES: Specialist physician payment model (salary-based or FFS). MAIN OUTCOMES AND MEASURES: Follow-up outpatient visits, guideline-recommended care delivery, adverse events, and costs. RESULTS: A total of 90 605 patients received care from FFS physicians and 19 234 received care from salary-based physicians. Before matching, the patients seen by salary-based physicians had more advanced chronic kidney disease (2630 of 14 414 [18.2%] vs 6627 of 54 489 [12.2%]), and a higher proportion had 5 or more comorbidities (5989 of 19 234 [31.3%] vs 23 326 of 90 605 [25.7%]). Propensity-score matching resulted in a cohort of 31 898 patients (15 949 FFS, 15 949 salary-based) seeing 489 specialists. In the matched cohort, patients were similar (mean [SD] age, 61.3 [18.2] years; 17 632 women [55.3%]; 29 251 residing in urban settings [91.7%]). Patients seen by salary-based specialists had a higher follow-up visit rate compared with those seen by FFS specialists (1.74 visits; 95% CI, 1.58-1.92 visits vs 1.54 visits; 95% CI, 1.41-1.68 visits), but the difference was not significant (rate ratio, 1.13; 95% CI, 0.99-1.28; P = .06). There was no statistical difference in guideline-recommended care delivery, hospital or emergency department visits for ambulatory care–sensitive conditions, or costs between patients seeing FFS and salary-based specialists. The median association of physician clustering with health care use and quality outcomes was consistently greater than the association with the physician payment, suggesting variation between physicians (eg, median rate ratio for follow-up outpatient visit rate was 1.74, which is greater than the rate ratio of 1.13). CONCLUSIONS AND RELEVANCE: Specialist physician payment does not appear to be associated with variation in visits, quality, and costs for outpatients with chronic diseases; however, there is variation in outcomes between physicians. This finding suggests the need to consider other strategies to reduce physician variation to improve the value of care and outcomes for people with chronic diseases.