Minimally important difference estimates and assessment of their credibility for patient-reported outcomes in adults: A systematic survey

Tags: Oral
Carrasco-Labra A1, Devji T1, Lytvyn L2, Brignardello-Petersen R1, Prasad M1, Devasenapathy N3, Zeraatkar D1, Foroutan F1, Pardo-Hernandez H4, Vernooij RW4, Jin X1, Ross S1, Quach K1, Schandelmaier S5, Panepinto O1, Bhatt M1, Qasim A1, Phillips M1, Furukawa TA6, Patrick DL7, Schünemann HJ1, Johnston BC8, Ebrahim S1, Nesrallah G9, Guyatt G1
1McMaster University, 2Oslo University Hospital, 3Indian Institute of Public Health-Delhi, 4Iberoamerican Cochrane Centre, 5Basel Institute for Clinical Epidemiology and Biostatistics, University Hospital Basel, 6Department of Health Promotion and Human Behavior, School of Public Health, Kyoto University Graduate School of Medicine, Kyoto, 7University of Washington, 8The Hospital for Sick Children, 9Humber River Regional Hospital

Background:Patient-reported outcomes (PROs) capture patients’ perspectives on treatment benefits and harms. Understanding PROs requires determining a level of improvement or deterioration that patients consider important. The most common reference point for interpretation of PROs is the minimal important difference (MID), which provides a measure of the smallest change in a PRO that patients perceive as an important benefit or harm. No inventory of MIDs is currently available. Thus, clinicians and patients have to navigate the vast literature in order to retrieve a specific MID. Even if they find an MID, there is no guidance to help them ascertain the trustworthiness of the apparently applicable MID.

Objectives:To create an inventory of published anchor-based MIDs associated with PROs used in evaluating the effects of interventions on chronic medical and psychiatric conditions in adults, including the context in which they were assessed (condition/disease), and the confidence users can place in a particular MID.

Methods:We searched MEDLINE, EMBASE, PsycINFO and CINAHL to identify studies addressing methods to estimate anchor-based MIDs of PROs or reporting empirical ascertainment of anchor-based MIDs. Teams of two reviewers independently screened citations, and identified and extracted relevant data. We collected information on study design, condition under assessment, population characteristics, characteristics of the PRO, and characteristics of the anchor. In addition, we created and applied a new tool to assess credibility of MID estimates. When multiple MIDs were reported for the same PRO across similar clinical conditions, we collected all these estimates.

Results:A total of 5656 citations were retrieved for title and abstract screening of which 1716 were selected for full-text screening and 610 studies reporting on one or more MID estimates proved eligible. We will report on the spectrum and credibility of available MID estimates at the GES.

Conclusion:Our inventory of available MIDs and their associated credibility will be of great use to clinical triallists, systematic review authors, patients and clinicians.