Minimally Important Differences in Patient or Proxy-Reported Outcome Studies Relevant to Children: A Systematic Review

Abstract

CONTEXT: No study has characterized and appraised all anchor-based minimally important differences (MIDs) associated with patient-reported outcome (PRO) instruments in pediatric studies. OBJECTIVE: To complete a comprehensive systematic survey and appraisal of published anchor-based MIDs associated with PRO instruments used in children. DATA SOURCES: Medline, Embase, and PsycINFO (1989 to February 11, 2015). STUDY SELECTION: Studies reporting empirical ascertainment of anchor-based MIDs among PROs used in pediatric care. DATA EXTRACTION: All pertinent data items related to the characteristics of PRO instruments, anchors, and MIDs. RESULTS: Of 4179 unique citations, 30 studies (including 32 cohorts) proved eligible and reported on 28 unique PROs (8 generic, 13 disease-specific, 5 symptoms-specific, 2 function-specific), with 9 (32%) classified as patient-reported, 11 (39%) proxy-reported, and 8 (29%) both patient- and proxy-reported. Of the 30 studies, we rated 14 (44%) as providing highly credible estimates of the MID. Most cohorts (n = 20, 62%) recorded patients’ direct response to the target PRO and the use of an independent standard of comparison (n = 25, 78%). Most, however, failed to effectively report measurement properties of the anchor (n = 24, 75%). LIMITATIONS: We have not yet addressed the measurement properties of instrument to measure credibility; our search was restricted to 3 electronic sources, and we used a single data abstractor. CONCLUSIONS: Our study found 28 PROs that have been developed for children, with fewer than half providing credible estimates. Clinicians, clinical trialists, systematic reviewers, and guideline developers seeking to effectively summarize and interpret results of studies addressing PROs in child health are likely to find our comprehensive compendium of MIDs of use, both in providing best estimates of MIDs and identifying credible estimates.