TY  - JOUR
PY  - 2020//
TI  - Responsiveness, minimal important difference, minimal relevant difference, and optimal number of patients for a study
JO  - Scandinavian journal of medicine and science in sports
A1  - Comins, Jonathan
A1  - Brodersen, John
A1  - Christensen, Karl Bang
A1  - Jensen, Jonas
A1  - Hansen, Christian Fugl
A1  - Krogsgaard, Michael R.
SP  - ePub
EP  - ePub
VL  - ePub
IS  - ePub
N2  - Several terms are used to describe changes in PROM scores in relation to treatments. Whether the change is small, large, or relevant is defined in different ways, yet these change scores are used to recommend or oppose treatments. They are also used to calculate the necessary number of patients for a study. This article offers a theoretical explanation behind the terms responsiveness, minimal important difference (MID), minimal important change (MIC), minimal relevant difference (MIREDIF), and threshold of clinical importance. It also gives instructions on how these and the optimal number of patients for a study are calculated. Responses to two domains of the Knee Injury and Osteoarthritis Outcome Score (KOOS), before, and 1 year after reconstruction of the anterior cruciate ligament of 164 patients, are used to illustrate the calculations. This paper presents the most common methods used to calculate and interpret MID. <br><br>RESULTS vary substantially across domains, patient location on the scale, and health conditions. The optimal number of patients depends on the minimal relevant difference (MIREDIF), the standard error of the measure (SEM), the desired statistical power for the measurement, and the responsiveness of the measurement instrument (the PROM). There is often uncertainty surrounding the calculation and interpretation of responsiveness, MID, and MIREDIF, as these concepts are complex. When MID is used to evaluate research results, authors should specify how the MID was calculated, and its relevance for the study population. These measures should only be used after thorough consideration to justify healthcare decisions.<p />  <p>Language: en</p>
LA  - en
SN  - 0905-7188
UR  - http://dx.doi.org/10.1111/sms.13855
ID  - ref1
ER  -