Sheffield, UK – In its Reference Case, the National Institute for Health and Care Excellence (NICE) states that where many algorithms exist, their effect on the results should be investigated, yet this has not been routinely done in economic evaluations in rheumatoid arthritis (RA).
To produce a cost per quality-adjusted life year, economic models require utility values – a measure of health-related quality of life. These measures of utility are not routinely included in trials for RA, so algorithms are often used to convert the Health Assessment Questionnaire (HAQ) to utilities.
Researchers from the University of Sheffield reviewed the literature and identified 24 different algorithms that have been or could be used to map from the HAQ to the EQ-5D (a measure of utility). They used all 24 of the different algorithms in the same RA model and compared the results. As a result, the researchers found that using different mapping algorithms led to results which varied above and below crucial willingness-to-pay thresholds, meaning the choice of algorithm could determine whether a drug is recommended.
Lead author Becky Pennington, MSc, a health economist at BresMed concluded: “The use of different algorithms could lead health technology assessment bodies to make different decisions regarding reimbursement.” Consequently, the wrong choice of algorithm could substantially cost the heath technology assessment body through reimbursement approval of a cost-ineffective drug, or the manufacturer in losing sales of a cost-effective drug.
The full study, “Mapping from the Health Assessment Questionnaire to the EQ-5D: The Impact of Different Algorithms on Cost-Effectiveness Results,” is published in Value in Health.