A systematic review of the evolution of health-economic evaluation models of osteoarthritis

Objective: To comprehensively synthesise the evolution of health-economic evaluation models (HEEMs) of all OA interventions including preventions, core treatments, adjunct non-pharmacological interventions, pharmacological and surgical treatments.

Methods: The literature was searched within health-economic/biomedical databases. Data extracted included: OA type, population characteristics, model setting/type/events, study perspective, comparators; and the reporting quality of the studies was assessed. The review protocol was registered at the International Prospective Register of Systematic Reviews (registration: CRD42018092937).

Results: Eighty-eight studies were included. Pharmacological and surgical interventions were the focus in 51% and 44% studies, respectively. Twenty-four studies adopted a societal perspective (with increasing popularity after 2013), however most (63%) did not include indirect costs. Quality-adjusted life years (QALYs) was the most popular outcome measure since 2008. Markov models were used by 62% of studies, with increasing popularity since 2008. Until 2010, most studies used short-to-medium time horizons; subsequently a lifetime horizon became popular. Eighty-six percent of studies reported discount rate(s) (predominantly between 3% and 5%). Studies published after 2002 had a better coverage of OA-related adverse events (AEs). Reporting quality significantly improved after 2001.

Conclusions: OA HEEMs have evolved and improved substantially over time, with focus shifting from short-to-medium-term pharmacological decision-tree models to surgical-focused lifetime Markov models. Indirect costs of OA are frequently not considered, despite using a societal perspective. There was lack of reporting sensitivity of model outcome to input parameters including discount rate, OA definition, and population parameters. Whilst the coverage of OA-related AEs has improved over time, it is still not comprehensive.