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Validation of clinic weights from electronic health records against standardized weight measurements in weight loss trials
Author(s) -
Xiao Lan,
Lv Nan,
Rosas Lisa G.,
Au David,
Ma Jun
Publication year - 2017
Publication title -
obesity
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.438
H-Index - 199
eISSN - 1930-739X
pISSN - 1930-7381
DOI - 10.1002/oby.21737
Subject(s) - concordance , medicine , confidence interval , concordance correlation coefficient , health records , standard error , correlation coefficient , linear regression , weight loss , statistics , mathematics , health care , obesity , economics , economic growth
Objective To validate clinic weights in electronic health records against researcher‐measured weights for outcome assessment in weight loss trials. Methods Clinic and researcher‐measured weights from a published trial (BE WELL) were compared using Lin's concordance correlation coefficient, Bland and Altman's limits of agreement, and polynomial regression model. Changes in clinic and researcher‐measured weights in BE WELL and another trial, E‐LITE, were analyzed using growth curve modeling. Results Among BE WELL ( n = 330) and E‐LITE ( n = 241) participants, 96% and 90% had clinic weights (mean [SD] of 5.8 [6.1] and 3.7 [3.9] records) over 12 and 15 months of follow‐up, respectively. The concordance correlation coefficient was 0.99, and limits of agreement plots showed no pattern between or within treatment groups, suggesting overall good agreement between researcher‐measured and nearest‐in‐time clinic weights up to 3 months. The 95% confidence intervals for predicted percent differences fell within ±3% for clinic weights within 3 months of the researcher‐measured weights. Furthermore, the growth curve slopes for clinic and researcher‐measured weights by treatment group did not differ significantly, suggesting similar inferences about treatment effects over time, in both trials. Conclusions Compared with researcher‐measured weights, close‐in‐time clinic weights showed high agreement and inference validity. Clinic weights could be a valid pragmatic outcome measure in weight loss studies.