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

Abstract

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).

Fig. 1

Study flowchart showing the EuroQol 5-dimension 3-level questionnaire (EQ-5D-3L) completed or not completed at discharge, 1 month, 6 months, and 12 months in the study follow-up period. CUA cost-utility analysis

Fig. 2

Cost-effectiveness plane with 1000 pairwise bootstrapped incremental cost-effectiveness ratios [ICERs] (left side) and the cost-effectiveness acceptability curve showing the probability of cost effectiveness at different willingness-to-pay thresholds for the intervention (right side) for the a full population (percentage of ICERs in the north-east quadrant [NE]: 80.80%, percentage of ICERs in the south-east quadrant [SE]: 6.20%, percentage of ICERs in the north-west quadrant [NW]: 12.70%, percentage of ICERs in the south-west quadrant [SW]: 0.03%), b non-long stayers (NE: 32.20%, SE: 67.80%, NW: 0.01%, SW: 0.00%), and c long stayers (NE: 0.07%, SE: 0.08%, NW: 57.30%, SW: 41.20%), respectively. The dotted lines represent minimum and maximum willingness to pay for the Norwegian setting (€27,067–81,200). QALY quality-adjusted life year