Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2021 Oct;30(10):2729-2754.
doi: 10.1007/s11136-021-02925-y. Epub 2021 Jul 10.

Minimal important change (MIC): a conceptual clarification and systematic review of MIC estimates of PROMIS measures

Caroline B Terwee  1 , John Devin Peipert  2 , Robert Chapman  2 , Jin-Shei Lai  2 , Berend Terluin  3 , David Cella  2 , Pip Griffiths  4 , Lidwine B Mokkink  5
Affiliations

Minimal important change (MIC): a conceptual clarification and systematic review of MIC estimates of PROMIS measures

Caroline B Terwee et al. Qual Life Res. 2021 Oct.

Abstract

We define the minimal important change (MIC) as a threshold for a minimal within-person change over time above which patients perceive themselves importantly changed. There is a lot of confusion about the concept of MIC, particularly about the concepts of minimal important change and minimal detectable change, which questions the validity of published MIC values. The aims of this study were: (1) to clarify the concept of MIC and how to use it; (2) to provide practical guidance for estimating methodologically sound MIC values; and (3) to improve the applicability of PROMIS by summarizing the available evidence on plausible PROMIS MIC values. We discuss the concept of MIC and how to use it and provide practical guidance for estimating MIC values. In addition, we performed a systematic review in PubMed on MIC values of any PROMIS measure from studies using recommended approaches. A total of 50 studies estimated the MIC of a PROMIS measure, of which 19 studies used less appropriate methods. MIC values of the remaining 31 studies ranged from 0.1 to 12.7 T-score points. We recommend to use the predictive modeling method, possibly supplemented with the vignette-based method, in future MIC studies. We consider a MIC value of 2-6 T-score points for PROMIS measures reasonable to assume at this point. For surgical interventions a higher MIC value might be appropriate. We recommend more high-quality studies estimating MIC values for PROMIS.

Keywords: Interpretation; Methodology; Minimal important change; PROMIS; Patient-reported outcomes.

PubMed Disclaimer

Conflict of interest statement

D. Cella was co-author on one of the included PROMIS MIC papers [44] and CB. Terwee was co-authors of another included PROMIS MIC paper [89], but both were not involved in the data extraction of these papers. CB. Terwee and D. Cella are board members of the PROMIS Health Organization. The other authors have no conflicts of interest to declare that are relevant to the content of this article.

Figures

Fig. 1
Fig. 1
MICmean and MICROC. On the left, the distribution of change scores in all patients who are ‘improved’ (larger distribution) and in patients who are ‘a little better’ (smaller distribution), on the right the distribution of change scores in patients who are ‘not improved’. The upper line represents the MICmean (based on the smaller distribution on the left side), the lower line represents the MICROC (based on the larger left-sided distribution and the right-sided distribution)
See this image and copyright information in PMC

References

    1. King MT. A point of minimal important difference (MID): A critique of terminology and methods. Expert Review of Pharmacoeconomics & Outcomes Research. 2011;11(2):171–184. doi: 10.1586/erp.11.9. - DOI - PubMed
    1. Devji T, Carrasco-Labra A, Qasim A, Phillips M, Johnston BC, Devasenapathy N, Zeraatkar D, Bhatt M, Jin X, Brignardello-Petersen R, Urquhart O, Foroutan F, Schandelmaier S, Pardo-Hernandez H, Vernooij RW, Huang H, Rizwan Y, Siemieniuk R, Lytvyn L, Patrick DL, Ebrahim S, Furukawa T, Nesrallah G, Schünemann HJ, Bhandari M, Thabane L, Guyatt GH. Evaluating the credibility of anchor based estimates of minimal important differences for patient reported outcomes: instrument development and reliability study. BMJ. 2020;369:m1714. doi: 10.1136/bmj.m1714. - DOI - PMC - PubMed
    1. de Vet HC, Terwee CB. The minimal detectable change should not replace the minimal important difference. Journal of Clinical Epidemiology. 2010;63(7):804–805. doi: 10.1016/j.jclinepi.2009.12.015. - DOI - PubMed
    1. de Vet HC, Terwee CB, Ostelo RW, Beckerman H, Knol DL, Bouter LM. Minimal changes in health status questionnaires: Distinction between minimally detectable change and minimally important change. Health and Quality of Life Outcomes. 2006;4:54. doi: 10.1186/1477-7525-4-54. - DOI - PMC - PubMed
    1. Terwee CB. Estimating minimal clinically important differences and minimal detectable change. Journal of Hand Surgery. 2019;44(12):e1. doi: 10.1016/j.jhsa.2019.10.001. - DOI - PubMed

Publication types

MeSH terms

LinkOut - more resources