Accounting for heterogeneity in resource allocation decisions: methods and practice in UK cancer technology appraisals

Objectives The availability of novel, more efficacious and expensive cancer therapies is increasing, resulting in significant treatment effect heterogeneity and complicated treatment and disease pathways. The aim of this study is to review the extent to which UK cancer technology appraisals (TAs) consider the impact of patient and treatment effect heterogeneity. Methods A systematic search of NICE TAs of colorectal, lung and ovarian cancer was undertaken for the period up to April 2020. For each TA, the pivotal clinical studies and economic evaluations were reviewed for considerations of patient and treatment effect heterogeneity. The study critically reviews the use of subgroup analysis and realworld translation in economic evaluations, alongside specific attributes of the economic modelling framework. Results The search identified 49 TAs including 49 economic models. In total, 804 subgroup analyses were reported across 69 clinical studies. The most common stratification factors were age, gender and Eastern Cooperative Oncology Group performance score, with 15% (119/804) of analyses demonstrating significantly different clinical outcomes to the main population; economic subgroup analyses were undertaken in only 17 TAs. All economic models were cohort-level with the majority described as partitioned survival models (39) or Markov/semi-Markov models (9). The impact of real-world heterogeneity on disease progression estimates was only explored in two models. Conclusions The ability of current modelling approaches to capture patient and treatment effect heterogeneity is constrained by their limited flexibility and simplistic nature. This study highlights a need for the use of more sophisticated modelling methods that enable greater consideration of real-world heterogeneity.