Application of minimal important differences in degenerative knee disease outcomes: a systematic review and case study to informBMJRapid Recommendations

Abstract

ObjectivesTo identify the most credible anchor-based minimal important differences (MIDs) for patient important outcomes in patients with degenerative knee disease, and to inform BMJ Rapid Recommendations for arthroscopic surgery versus conservative managementDesignSystematic review.Outcome measuresEstimates of anchor-based MIDs, and their credibility, for knee symptoms and health-related quality of life (HRQoL).Data sourcesMEDLINE, EMBASE and PsycINFO.Eligibility criteriaWe included original studies documenting the development of anchor-based MIDs for patient-reported outcomes (PROs) reported in randomised controlled trials included in the linked systematic review and meta-analysis and judged by the parallel BMJ Rapid Recommendations panel as critically important for informing their recommendation: measures of pain, function and HRQoL.Results13 studies reported 95 empirically estimated anchor-based MIDs for 8 PRO instruments and/or their subdomains that measure knee pain, function or HRQoL. All studies used a transition rating (global rating of change) as the anchor to ascertain the MID. Among PROs with more than 1 estimated MID, we found wide variation in MID values. Many studies suffered from serious methodological limitations. We identified the following most credible MIDs: Western Ontario and McMaster University Osteoarthritis Index (WOMAC; pain: 12, function: 13), Knee injury and Osteoarthritis Outcome Score (KOOS; pain: 12, activities of daily living: 8) and EuroQol five dimensions Questionnaire (EQ-5D; 0.15).ConclusionsWe were able to distinguish between more and less credible MID estimates and provide best estimates for key instruments that informed evidence presentation in the associated systematic review and judgements made by the Rapid Recommendation panel.Trial registration numberCRD42016047912.

A Randomized Controlled Single-Blind Study Demonstrating Superiority of Amniotic Suspension Allograft Injection Over Hyaluronic Acid and Saline Control for Modification of Knee Osteoarthritis Symptoms

“…For KOOS scores, the MID has been reported as an 8-to 10point change. 13,31,32 In the current study, among patients treated with HA, the change in baseline for KOOS subsets scores, including pain, symptoms, and ADL, at 3 and 6 months were below this MID, while sports and recreation, and quality-of-life values achieved MID (►Supplementary Table 1). Patients who received ASA achieved the MID for all KOOS subsets (►Supplementary Table 1).…”

A novel Wnt pathway inhibitor, SM04690, for the treatment of moderate to severe osteoarthritis of the knee: results of a 24-week, randomized, controlled, phase 1 study

“…Positive changes from baseline in MDGA and VAS pain scores were also observed in all groups at 12 and 24 weeks (Table III). While there were clinically relevant 22 changes from baseline within cohorts, no statistically significant differences between treatment cohorts and PBO were observed for any measurements.…”

Knee arthroscopy versus conservative management in patients with degenerative knee disease: a systematic review

“…These MIDs were obtained from a systematic review of studies in which patients were directly asked about the magnitude of change they had experienced, and whether that change was trivial, small but important, or larger. 16 Clinical experts who were part of the team of that systematic review judged the applicability of such studies to the target population and raised no concerns.…”