MCID (Jaeschke)

Measurement of health status. Ascertaining the minimal clinically important difference

Jaeschke R, Singer J, Guyatt GH Controlled clinical trials 1989 · PMID 2691207 · doi:10.1016/0197-2456(89)90005-6

Question

What is the smallest change in a health status score that patients perceive as beneficial?

Design

Methodological study introducing the MCID concept, estimated using patient global ratings in questionnaires for chronic heart and lung disease.

Patients

Patients with chronic respiratory and heart disease completing health-related quality of life questionnaires.

Intervention

Anchor-based approach linking score change to patient global rating of change

Comparison

Not applicable

Primary outcome

Minimal clinically important difference in questionnaire scores

Key result

Defined the MCID as the smallest difference in score that patients perceive as beneficial and that would mandate a change in management, and showed it could be estimated using global ratings of change.

Limitations

Derived outside orthopaedics; MCID values are instrument-, population- and method-specific.

Impact on practice

The founding definition of MCID, now central to sample size calculations and interpretation of PROMs in orthopaedic trials: statistical significance alone does not mean clinical importance.