A Trial-Based Cost-Utility Analysis of a Medication Optimization Intervention Versus Standard Care in Older Adults.

Background: Older adults are at greater risk of medication-related harm than younger adults. The Integrated Medication Management model is an interdisciplinary method aiming to optimize medication therapy and improve patient outcomes.

Objective: We aimed to investigate the cost effectiveness of a medication optimization intervention compared to standard care in acutely hospitalized older adults.

Methods: A cost-utility analysis including 285 adults aged ≥ 70 years was carried out alongside the IMMENSE study. Quality-adjusted life years (QALYs) were derived using the EuroQol 5-Dimension 3-Level Health State Questionnaire (EQ-5D-3L). Patient-level data for healthcare use and costs were obtained from administrative registers, taking a healthcare perspective. The incremental cost-effectiveness ratio was estimated for a 12-month follow-up and compared to a societal willingness-to-pay range of €/QALY 27,067-81,200 (NOK 275,000-825,000). Because of a capacity issue in a primary care resulting in extended hospital stays, a subgroup analysis was carried out for non-long and long stayers with hospitalizations < 14 days or ≥ 14 days.

Results: Mean QALYs were 0.023 [95% confidence interval [CI] 0.022-0.025] higher and mean healthcare costs were €4429 [95% CI - 1101 to 11,926] higher for the intervention group in a full population analysis. This produced an incremental cost-effectiveness ratio of €192,565/QALY. For the subgroup analysis, mean QALYs were 0.067 [95% CI 0.066-0.070, n = 222] and - 0.101 [95% CI - 0.035 to 0.048, n = 63] for the intervention group in the non-long stayers and long stayers, respectively. Corresponding mean costs were €- 824 [95% CI - 3869 to 2066] and €1992 [95% CI - 17,964 to 18,811], respectively. The intervention dominated standard care for the non-long stayers with a probability of cost effectiveness of 93.1-99.2% for the whole willingness-to-pay range and 67.8% at a zero willingness to pay. Hospitalizations were the main cost driver, and readmissions contributed the most to the cost difference between the groups.

Conclusions: According to societal willingness-to-pay thresholds, the medication optimization intervention was not cost effective compared to standard care for the full population. The intervention dominated standard care for the non-long stayers, with a high probability of cost effectiveness.

Clinical Trial Registration: The IMMENSE trial was registered in ClinicalTrials.gov on 28 June, 2016 before enrolment started (NCT02816086).