The effect of a health-system real-time prescription benefit tool on primary medication adherence: an interrupted time series study



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Background: Real-time prescription benefit (RTPB) tools are intended to provide accurate outpatient medication cost information to providers at the point of prescribing. This may allow for meaningful affordability discussions between providers and patients. While becoming more widespread, there is limited evidence on the effectiveness of this functionality on clinical and economic outcomes. Objective: To evaluate the effect of an integrated RTPB module on primary medication adherence and medication costs. Methods: This single-site, uncontrolled, interrupted time series analysis utilized case-level retrospective medication order and dispensing data from a large integrated delivery network (IDN) in Texas (2018-2022). Eligible outpatient medication orders (for branded diabetes medications, respiratory maintenance inhalers, and attention deficit/hyperactivity disorder [ADHD] medications) electronically prescribed for dispensing at the health system pharmacy network were examined for sales within 30 days of the order date (primary medication adherence). Segmented generalized linear regression models were used to model the association between RTPB functionality on instantaneous and durable changes in primary medication adherence rates and secondary medication cost outcomes. Results: A total of 54,328 medication orders met all study criteria (pre-intervention, N=27,425; post-intervention, N=26,903). In the post-intervention period, 67.3% of orders triggered an RTPB alert; however, only 0.5% of these were proactively initiated by the prescriber. Overall, the RTPB module was associated with an instantaneous decrease (23.6%; 95% CI; 14.7-31.6%) in odds and a monthly decrease (3.0%; 95% CI; 2.3-3.7%) in odds of 30-day primary medication adherence. This was consistent in analyses of respiratory inhaler and ADHD subsets. There was no association between RTPB functionality and out-of-pocket costs, except for an instantaneous decrease (25.0%; 95% CI; 5.4-40.4%) in the inhaler subset. Lastly, the RTPB module was associated with an instantaneous increase (7.2%; 95% CI; 3.0-11.7%) and a monthly increase (1.2%; 95% CI; 0.8-1.6%) in total medication costs, but medication subset analyses were conflicting. Conclusion: While evidence of a benefit from RTPB functionality was mixed, there was evidence of time-varying confounding that was not accounted for due to lack of a control group. Notably, while response rates of the RTPB module were high, there is minimal use of the more proactive component of the tool.


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