Association Between Increased Hospital Reimbursement for Cardiac Rehabilitation and Utilization of Cardiac Rehabilitation by Medicare Beneficiaries: An Interrupted Time Series

Background: Although cardiac rehabilitation (CR) is a Class I Guideline recommendation, and has been shown to be a cost-effective intervention after a cardiac event, it has been reimbursed at levels insufficient to cover hospital operating costs. In January 2011, Medicare increased payment for CR in hospital outpatient settings by ≈180%. We evaluated the association between this payment increase and participation in CR of eligible Medicare beneficiaries to better understand the relationship between reimbursement policy and CR utilization.

Methods: From a 5% Medicare claims sample, we identified patients with acute myocardial infarction, coronary artery bypass surgery, percutaneous coronary intervention, or cardiac valve surgery between January 1, 2009 and September 30, 2012, alive 30 days after their event, with continuous enrollment in Medicare fee-for-service, Part A/B for 4 months. Trends and changes in CR participation were estimated using an interrupted time series approach with a hierarchical logistic model, hospital random intercepts, adjusted for patient, hospital, market, and seasonality factors. Estimates were expressed using average marginal effects on a percent scale.

Results: Among 76 695 eligible patients, average annual CR participation was 19.5% overall. In the period before payment increase, adjusted annual participation grew by 1.1 percentage points (95% CI, 0.48-2.4). No immediate change occurred in CR participation when the new payment was implemented. In the period after payment increase, on average, 20% of patients participated in CR annually. The annual growth rate in CR participation slowed in the post-period by 1.3 percentage points (95% CI, -2.4 to -0.12) compared with the prior period. Results were somewhat sensitive to time window variations.

Conclusions: The 2011 increase in Medicare reimbursement for CR was not associated with an increase in participation. Future studies should evaluate whether payment did not reach a threshold to incentivize hospitals or if hospitals were not sensitive to reimbursement changes.