Costs and cost-effectiveness of a medication-related clinical decision support system in patients with polypharmacy in a primary care setting: a health economic evaluation alongside a stepped-wedge cluster-randomized controlled trial

Abstract Background Inappropriate prescribing in primary care is a major cause of morbidity, hospitalizations, and mortality worldwide. While Clinical Decision Support Systems (CDSS) have been developed to assist general practitioners (GPs) in optimizing medication management and improving patient safety, evidence on the health economic impact of medication-related CDSS remains limited and inconclusive. Therefore, this health economic evaluation alongside a stepped-wedge cluster-randomized controlled trial assessed the costs and cost-effectiveness of a CDSS-supported medication review implemented in German GP practices compared to standard care over up to 14 quarters. Results Overall, from a payer’s perspective, the intervention was associated with non-significant mean cost savings of -7.2 € per patient per quarter in total healthcare costs (95% CI: -109.7 to 95.3; p = 0.891). Whereas outpatient costs with 9.3 € (95% CI: 1.9 to 16.6; p = 0.014) were significantly higher in the intervention group (IG), inpatient costs and pharmaceutical costs were non-significantly lower in the IG, resulting in cost differences of -19.9 € (95% CI: -90.6 to 50.8; p = 0.581), and − 15.8 € (95% CI: -42.1 to 10.5; p = 0.238), respectively. The cost-effectiveness analysis, reporting incremental cost per 1% point reduction in the risk ratio, indicated substantial uncertainty, with the probability of cost-effectiveness not exceeding 62% at the highest willingness-to-pay threshold tested. Conclusions These findings are consistent with recent evidence showing uncertain economic benefits of CDSS interventions. Limited uptake of the CDSS in this trial likely constrained its effectiveness. Future research should therefore adopt more comprehensive evaluations integrating clinical, economic, and implementation perspectives to better understand the contextual factors and mechanisms under which CDSS interventions can generate its full impact. A better understanding of these factors will inform strategies to enhance adoption, effectiveness, and economic efficiency of CDSS in medication management. Trial registration ClinicalTrials.gov NCT03430336. Registered on 2018/02/06.