Reference pricing (RP) is an insurance design that can be used to incentivize patients to use low-price settings. While RP is not intended to affect overall utilization, it could unintentionally reduce utilization. We examined whether utilization was reduced when a large employer adopted RP for selected elective surgeries, including inpatient joint replacement surgery and outpatient cataract surgery, colonoscopy, and arthroscopic surgery. Data included a treatment group subject to RP implementation and a comparison group that was not. We applied autoregressive integrated moving average analysis as comparison-population interrupted time-series analysis to determine whether there were procedure reductions following RP implementation. We find no evidence of short-term decreases (within 3 months of RP implementation). However, we find very modest declines of approximately 14 (20%) fewer arthroscopic knee surgeries 6 months after RP implementation and 129 (17.2%) fewer colonoscopies 8 months after RP implementation. There were no declines in the other procedures examined.
Keywords: ARIMA; interrupted time series; reference pricing; service utilization.