A desirability of outcome ranking (DOOR) for periprosthetic joint infection - a Delphi analysis

Abstract

Background: Treatment outcomes in studies on prosthetic joint infection are generally assessed using a dichotomous outcome relating to treatment success or failure. These outcome measures neither include patient-centred outcome measures including joint function and quality of life, nor do they account for adverse effects of treatment. A desirability of outcome ranking (DOOR) measure can include these factors and has previously been proposed and validated for other serious infections. We aimed to develop a novel DOOR for prosthetic joint infections (PJIs). Methods: The Delphi method was used to develop a DOOR for PJI research. An international working group of 18 clinicians (orthopaedic surgeons and infectious disease specialists) completed the Delphi process. The final DOOR comprised the dimensions established to be most important by consensus with $>75$ % of participant agreement. Results: The consensus DOOR comprised four main dimensions. The primary dimension was patient-reported joint function. The secondary dimensions were infection cure and mortality. The final dimension of quality of life was selected as a tie-breaker. Discussion: A desirability of outcome ranking for periprosthetic joint infection has been proposed. It focuses on patient-centric outcome measures of joint function, cure and quality of life. This DOOR provides a multidimensional assessment to comprehensively rank outcomes when comparing treatments for prosthetic joint infection.

Figure 1

Proposed consensus DOOR for PJI. Joint function was defined as good for knees, with the Oxford Knee Score $\ge \mathrm{32.5}$ , and for hips, with the Oxford Hip Score $\ge \mathrm{37.5}$ (Hamilton et al., 2018). Infection cure was defined by the international consensus criteria (Diaz-Ledezma et al., 2013). The overall health score, using the 12-item short-form health survey (SF-12) with a cut-off for a good outcome of $\ge \mathrm{36}$ on the physical scale and $\ge \mathrm{53}$ on the mental scale (Helwig et al., 2014).

Figure 2

Domain ranking for general ranking experiments in the first round of the Delphi process. Percentages shown as a cumulative number of respondents who selected the domain as the most important or second most important from the ranking question.