Clinical and Cost Outcomes Associated with Cardiologist Payment Models: A Qualitative Systematic Review.

BACKGROUND: Payment models for cardiologists create financial incentives that can influence clinical decision-making and healthcare costs. In addition, some cardiologists may order diagnostic tests and procedures on equipment they own, which increases the likelihood of such tests being ordered. We aimed to assess the influence of cardiologist payment models on clinical and health system cost outcomes. METHODS: We searched MEDLINE, Embase, Cochrane Central Register of Controlled Trials, National Health Service Economic Evaluation Database, EconLit, and Web of Science, for the period from database inception to August 2025. Studies were included if they examined cardiologist payment models and reported clinical and cost outcomes using randomized controlled trials, controlled clinical trials, controlled before-after studies, interrupted time series, or observational study designs. RESULTS: Of 4156 identified studies, 6 met the inclusion criteria. Within studies that evaluated patient volume in a fee-for-service (FFS) model, high-volume FFS cardiologists ordered more diagnostic tests than did low-billing FFS cardiologists, and high-billing cardiologists billed a lower volume of procedures. We observed a higher incidence of hospitalizations in patients with atrial fibrillation in the highest billing cohort, but a lower incidence in patients with heart failure. Among studies that directly compared payment models, diagnostic test utilization was consistently higher in FFS models than in non-FFS payment models. CONCLUSIONS: FFS cardiologists order more diagnostic tests, which may lead to higher health system costs. Increased testing did not lead to improvement in key patient outcomes. Further research is needed to examine the relationship between cardiologist payment models, cost, and clinical outcomes of the care provided.