Methods for Including Adverse Events in Economic Evaluations: Suggestions for Improvement

Adverse Event Costs and Cost-Effectiveness Analyses of Anticancer Drugs: A Systematic Review

Importance

Accurately quantifying adverse event (AE) costs is essential for cost-effectiveness analyses (CEAs) of anticancer drugs. Misestimates in AE costs may significantly affect cost-effectiveness conclusions.

Objective

To assess whether AE cost quantification in anticancer drug CEAs accurately reflects the true cost of AEs and to evaluate whether replacing AE costs with actual values affects cost-effectiveness conclusions.

Evidence Review

A systematic search of PubMed, Web of Science, and Tufts CEA databases was conducted from October 24 to December 1, 2023, with an additional search from November 4 to 10, 2024, for English-language CEAs and claims-based studies examining AE costs for anticancer drugs published between January 2003 and December 2023. Claims-based AE costs were considered to represent actual values. AE costs were compared in absolute terms and as a proportion of total medical costs. Impact of replacing CEA AE cost estimates with actual values for incremental cost-effectiveness ratios (ICERs) was examined at thresholds of $100 000 and $150 000 per quality-adjusted life year (QALY). AE cost differences between CEA estimates and actual values and their impact on ICERs were the main outcomes.

Findings

The sample included 11 claims-based US studies with 34 022 patients and 102 US payer-perspective CEAs. AE cost estimates in CEAs were consistently lower than actual values, with a median difference of 9.73% (IQR, 5.15%-27.22%; P = .002) in proportion of total medical costs and of $17 201 (IQR, $13 365-$48 970; P = .03) in absolute costs. Adjusting AE costs led to an ICER change of $42 656 per QALY, altering cost-effectiveness conclusions in 8 of 17 cases (47.1%). Among the 102 CEAs, 41 (40.2%) did not report AE types; of the remaining 61 (59.8%), 48 (78.7%) focused on treatment-related AEs instead of all-cause AEs. Of all CEAs, 79 (77.5%) considered grade 3 or higher AEs, ignoring grades 1 and 2. Only 13 studies (12.7%) accounted for AE-related dose reductions or interruptions, 87 (85.3%) did not consider postprogression AE costs, and 77 (82.8%) assumed AEs occurred only in the first treatment cycle. Substantial variability was observed in both drug AE and unit AE costs across studies.

Conclusions and Relevance

In this systematic review of AE costs in oncology CEAs, AE costs were frequently underestimated, potentially altering cost-effectiveness conclusions. Key problems included incomplete AE inclusion, inaccurate AE cost estimates, overlooked long-term AEs, and unaccounted dose modifications. Best practices and standardized guidelines should be established to improve AE cost quantification in oncology CEAs.

Sensitivity of Cost-Effectiveness to Inclusion of Adverse Drug Events: A Scoping Review of Economic Models of Pharmacological Interventions for Diabetes, Diabetic Retinopathy, and Diabetic Macular Edema

Purpose

Incorporation of adverse drug events (ADEs) is suboptimal in economic evaluation, and thus the information provided by it may be inaccurate. Better guidance on incorporating ADEs into economic evaluation prompts for exploring whether the results are sensitive to ADEs.

Methods

This scoping review explored 242 cost-effectiveness models for pharmacological interventions for type 1 (T1DM) and 2 diabetes (T2DM), diabetic retinopathy (DR), and diabetic macular edema (DME), in relation to the type of ADEs included in the models (if any), whether the results were sensitive to the ADEs, and what could explain their potential impact.

Results

Of the analyses partly or completely including ADEs, 62% examined their impact on the results, with half of them (50%) reporting ADE-related sensitivity. The models included common to very common ADEs, and some rare but severe ones. The main reasons for excluding ADEs were low incidence (13%) and no reporting in clinical trials (13%). Many analyses reported no reason for the exclusion (53%). The analyses for T1DM and DR or DME included more severe ADEs and reported a higher ADE-related sensitivity compared to the analyses of T2DM (76,2%, 77.8%, and 46.4%, respectively). Higher incidence of ADEs (60,0%) and time trade off method (72,2%) were associated with higher ADE-related sensitivity (72,2%).

Conclusion

Incidence, condition, and the measure of utility were associated with the results being sensitive to ADEs. ADEs are an important outcome for the results of economic evaluation and better guidance on their inclusion and exclusion is needed.