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 Sep:137:200-208.
doi: 10.1016/j.jclinepi.2021.04.002. Epub 2021 Apr 20.

Effective dose 50 method as the minimal clinically important difference: Evidence from depression trials

Clarissa Bauer-Staeb  1 , Daphne-Zacharenia Kounali  2 , Nicky J Welton  2 , Emma Griffith  3 , Nicola J Wiles  2 , Glyn Lewis  4 , Julian J Faraway  5 , Katherine S Button  6
Affiliations

Effective dose 50 method as the minimal clinically important difference: Evidence from depression trials

Clarissa Bauer-Staeb et al. J Clin Epidemiol. 2021 Sep.

Abstract

Objective: Previous research on the minimal clinically important difference (MCID) for depression and anxiety is based on population averages. The present study aimed to identify the MCID across the spectrum of baseline severity.

Study design and settings: The present analysis used secondary data from 2 randomized controlled trials for depression (n = 1,122) to calibrate the Global Rating of Change with the PHQ-9 and GAD-7. The MCID was defined as a change in scores corresponding to a 50% probability of patients "feeling better", given their baseline severity, referred to as Effective Dose 50 (ED50).

Results: MCID estimates depended on baseline severity and ranged from no change for very mild up to 14 points (52%) on the PHQ-9 and up to 10 points (48%) on the GAD-7 for very high severity. The average MCID estimates were 3.7 points (23%) and 3.3 (28%) for the PHQ-9 and GAD-7 respectively.

Conclusion: The ED50 method generates MCID estimates across the spectrum of baseline severity, offering greater precision but at the cost of greater complexity relative to population average estimates. This has important implications for evaluations of treatments and clinical practice where users can use these results to tailor the MCID to specific populations according to baseline severities.

Keywords: Clinically Meaningful Change; GAD-7; MCID; Minimal Clinically Important Difference; PHQ-9; Primary Care.

PubMed Disclaimer

References

    1. World Health Organisation . World Health Organization; Geneva: 2017. Depression and other common mental disorders: global health estimates.
    1. McGlothlin AE, Lewis RJ. Minimal clinically important difference: defining what really matters to patients. JAMA. 2014;312(13):1342–1343. doi: 10.1001/jama.2014.13128. - DOI - PubMed
    1. Rai SK, Yazdany J, Fortin PR, Aviña-Zubieta JA. Approaches for estimating minimal clinically important differences in systemic lupus erythematosus. Arthritis Res Ther. 2015;17(1):143. doi: 10.1186/s13075-015-0658-6. - DOI - PMC - PubMed
    1. Copay AG, Subach BR, Glassman SD, Polly Jr DW, Schuler TC. Understanding the minimum clinically important difference: a review of concepts and methods. The Spine Journal. 2007;7(5):541–546. doi: 10.1016/j.spinee.2007.01.008. - DOI - PubMed
    1. Button KS, Kounali D, Thomas L, Wiles NJ, Peters TJ, Welton NJ. Minimal clinically important difference on the Beck Depression Inventory-II according to the patient's perspective. Psychol Med. 2015;45(15):3269–3279. doi: 10.1017/S0033291715001270. - DOI - PMC - PubMed

Publication types

Associated data