Treatment Effect Waning Assumptions: A Review of National Institute of Health and Care Excellence Technology Appraisals

Abstract

OBJECTIVES: Review National Institute of Health and Care Excellence (NICE) technology assessments to gain insights into the implementation of treatment effect waning, whereby the hazard or survival in an assessed technology converges to that of the comparator. This analysis aims to contribute to inform future guidance in this area. METHODS: Technology appraisals published 20/10/2021- 20/09/2023 were reviewed and data extracted on treatment effect waning circumstances, methods and rationale to compile a database based on three research questions: When are treatment effect waning assumptions used? What methods are used? Why have the company/Evidence Assessment Group/Committee preferred these methods? RESULTS: Both the EAG/company and the Committee included treatment effect waning assumptions in 28 appraisals. There was no pattern of waning assumptions between shorter (<20 years) and longer (>20 years) time horizons. The most prominent time point for applying waning assumptions was at 5 years, with 30/59 (50.8%) of the methods applied used 5 years. Stopping rules were used in 21/30 (70.1%) of the appraisals where Committee included waning, and waning assumptions were used more in oncology. The most common reason given for including treatment effect waning assumptions was precedent from prior appraisals. CONCLUSIONS: Considerable heterogeneity existed in both the methods used and justifications given for treatment effect waning assumptions. This variability poses a risk of inconsistent decision-making. Reliance on past appraisals emphasises the necessity to advocate for evidence-driven approaches and underscores the demand for guidance on suitable methods for incorporating assumptions.