Content comparison of utility and effectiveness instruments to the Prosthetic Interventions Core Outcome Set: a step to inform the benefits measured in lower-limb prosthetic health economic evaluations

Abstract

Purpose Health Economic Evaluations (HEEs) calculate a cost-benefit ratio using utility and effectiveness instruments. It is unknown whether existing instruments measure the items of the Prosthetic Interventions Core Outcome Set (PI-COS) that represent the benefits most important to lower-limb prosthesis users and funders. Comparing the content of existing instruments against the PI-COS will support instrument selection for future prosthetic HEEs. Materials and methods Utility and effectiveness instruments used to evaluate prosthetic interventions were identified and their International Classification of Functioning, Disability and Health framework (ICF) linking results were extracted. Content of each instrument was compared to the PI-COS through three metrics: content density, content diversity and bandwidth. Results Of the 130 utility and effectiveness instruments, 24 had previously been linked to the ICF. The instrument with the greatest bandwidth (i.e., broadest content coverage of the PI-COS) was the SF-36 given it linked to 6 of the 14 items of the PI-COS. Combining PROMIS subscales and short-forms allow measurement of a greater range of the PI-COS items. Conclusions There is no perfect fit instrument providing coverage of the PI-COS using the metrics of content density, content diversity and bandwidth. The PROMIS instrument may provide increase coverage of the PI-COS in future HEEs.