TY - JOUR
T1 - Anchored Minimal Clinically Important Difference Metrics
T2 - Considerations for Bias and Regression to the Mean
AU - Tenan, Matthew S.
AU - Simon, Janet E.
AU - Robins, Richard J.
AU - Lee, Ian
AU - Sheean, Andrew J.
AU - Dickens, Jonathan F.
N1 - Publisher Copyright:
Ó by the National Athletic Trainers’ Association, Inc
PY - 2021/9
Y1 - 2021/9
N2 - Minimal clinically important differences (MCIDs) are used to understand clinical relevance. However, repeated observations produce biased analyses unless one accounts for baseline observation, known as regression to the mean (RTM). Using an International Knee Documentation Committee (IKDC) survey dataset, we can demonstrate the effect of RTM on MCID values by (1) MCID-estimate dependence on baseline observation and (2) MCID-estimate bias being higher when the posttest-pretest data correlation is lower. We created 10 IKDC datasets with 5000 patients and a specific correlation under both equal and unequal variances. For each 10-point increase in baseline IKDC, MCID decreased by 3.5, 2.7, 1.9, 1.2, and 0.7 points when posttest-pretest correlations were 0.10, 0.25, 0.50, 0.75, and 0.90, respectively, under equal variances. Not accounting for RTM resulted in a static 20-point MCID. Minimal clinically important difference estimates may be unreliable. Minimal clinically important difference calculations should include the correlation and variances between posttest and pretest data, and researchers should consider using a baseline covariate-adjusted receiver operating characteristic curve analysis to calculate MCID.
AB - Minimal clinically important differences (MCIDs) are used to understand clinical relevance. However, repeated observations produce biased analyses unless one accounts for baseline observation, known as regression to the mean (RTM). Using an International Knee Documentation Committee (IKDC) survey dataset, we can demonstrate the effect of RTM on MCID values by (1) MCID-estimate dependence on baseline observation and (2) MCID-estimate bias being higher when the posttest-pretest data correlation is lower. We created 10 IKDC datasets with 5000 patients and a specific correlation under both equal and unequal variances. For each 10-point increase in baseline IKDC, MCID decreased by 3.5, 2.7, 1.9, 1.2, and 0.7 points when posttest-pretest correlations were 0.10, 0.25, 0.50, 0.75, and 0.90, respectively, under equal variances. Not accounting for RTM resulted in a static 20-point MCID. Minimal clinically important difference estimates may be unreliable. Minimal clinically important difference calculations should include the correlation and variances between posttest and pretest data, and researchers should consider using a baseline covariate-adjusted receiver operating characteristic curve analysis to calculate MCID.
KW - Patient-reported outcomes
KW - Statistics
KW - Validity
UR - http://www.scopus.com/inward/record.url?scp=85115326176&partnerID=8YFLogxK
U2 - 10.4085/1062-6050-0368.20
DO - 10.4085/1062-6050-0368.20
M3 - Article
C2 - 33237997
AN - SCOPUS:85115326176
SN - 1062-6050
VL - 56
SP - 1042
EP - 1049
JO - Journal of Athletic Training
JF - Journal of Athletic Training
IS - 9
ER -