QALYs and ambulatory status: societal preferences for healthcare decision making

Background This research aimed to review the theoretical and methodological aspects of the quality-adjusted life year (QALY) which give rise to potential for bias against certain patient populations, including those with problems with walking or an inability to walk (ambulatory disabilities), when health technology assessment decisions rely on QALY gain to show cost-effectiveness. Societal preferences for treating ambulatory versus non-ambulatory patients were also investigated. Methods We reviewed published literature to identify information on theoretical underpinnings of the QALY, measurement of utilities for QALY assessment, and empirical evidence of societal preferences for the treatment of ambulatory and non-ambulatory patients. Results and discussion Health states which represent mobility impairment and the inability to walk receive low valuation from general public preferences. Non-ambulatory patients, for example those with advanced neuromuscular disease, have lower utilities determined by standardized preference-based measurement (PBM) tools. Any treatment that increases survival but could not restore ambulation would result in lower lifetime QALY gains for non-ambulatory versus ambulatory patients. Treatments could therefore potentially be deemed less cost-effective, or not cost-effective at all for this patient population. Empirical research indicates a societal preference for equal treatment of patients regardless of ambulatory status. The main limitation of our review was the non-systematic approach to evidence search and review, however, given the broad scope of content required to meet the aims of the review, we believe that the targeted approach was appropriate. The evidence presented in this article highlights the need for alternatives to strict QALY-based approaches to prevent avoidable health inequities when determining cost-effectiveness of healthcare interventions for non-ambulatory populations against fixed cost-effectiveness thresholds. An alternative metric, the Equal Value of Life Years Gained (evLYG), has been proposed as a supplementary measure for use alongside the QALY for its potential to alleviate bias against disabled patient populations during the assessment of healthcare treatments.