2.6. Stage 3: rating interventions on the criteria

Data for 75 OA interventions and evidence about their performance on the criteria established from Stage 1 were extracted from the 2018 Royal Australian College of General Practitioners guideline for hip and knee OA (RACGP CPG) [35]. This information provided the most complete, rigorous, NZ-relevant and up-to-date evidence at the time to rate the interventions on six of the criteria: Duration, Effectiveness, Recommendation, Risk-Mild, Risk-Serious and Quality. Accessibility was estimated via a Delphi exercise involving a nationally representative panel of NZ OA researchers, independent from participants in our earlier study [32]. Cost was estimated using data and methods described in a systematic review [36]. A GRADE evaluation was conducted for total joint replacement (TJR), which was not included in the guideline evidence tables, to inform its performance on the criteria.

Each intervention was rated on the criteria and summarised into three ‘performance matrices’ for first-, second- and third-line OA care [37]. To align the CPG recommendations with first-, second- and third-line OA care, the authors (JC, AMB, JHA) developed a rubric to transform the guideline-assigned levels of recommendation (for any OA) into three categories for first-, second- and third-line OA care (Supplement 5; methods detailed in Supplement 2, page 14).