Medical Record Versus Researcher Measures of Height and Weight

Abstract

This study examined the extent of agreement between medical record and researcher measures of height and weight in adults and assessed the clinical significance of any resulting differences in body mass index (BMI) (kg/m(2)) according to the categorizations of underweight, normal weight, and overweight. Medical record and researcher measurements for height (n = 85), preoperative weight (n = 84), and postoperative weight (n = 65) in older patients undergoing elective coronary artery bypass grafting were used for analysis. Researcher measurements of height and weight were obtained by the same person and were compared to height and weight measurements extracted from the medical record. Bland and Altman's limits of agreement method was used to determine the extent of measurement error between medical record and researcher values. Cohen's kappa was used to assess for clinical significance of the differences in BMI categories based on medical record and researcher measurements. For height, 7% of the values were outside the 95% limits of agreement. For preoperative and postoperative weight, less than 5% of the values were outside the 95% limits of agreement. There were no significant differences in BMI categorization using Cohen's kappa between medical record and researcher measurements. Although there may be some measurement error for height in the medical record, weight measurements may have less error and the amount of measurement error may not be clinically relevant. Height and weight measurements extracted from the medical record are reliable and accurate in patients admitted for elective surgery, as are weight measurements obtained in stable postoperative patients.