Body mass index and waist circumference documentation in Canadian primary care electronic medical records

Abstract Background: Electronic medical records (EMR) are commonly used in primary care to document patient measurements including height and weight that are then used to produce body mass index (BMI) scores. However, little is known about the proportion of waist circumference (WC) documentation compared to BMI and the characteristics of patients with these measures. This study used a pan-Canadian research database, sourced from primary care EMRs, to describe BMI and WC documentation in primary care. Methods: A retrospective cohort design of primary care providers participating in the Canadian Primary Care Sentinel Surveillance Network (CPCSSN), this study presented descriptive, observational findings of EMR inputs. Frequencies and percentages of median BMI and WC documentation in CPCSSN EMRs and patient demographic characteristics are compared. Results: Of 707,819 Canadian patients aged of 40 or older, at least one BMI input was recorded for 58.6% and 11.5% had WC notations. The majority of patients (98.1%) with at least one WC measurement also had a BMI measurement while conversely 19.2% of patients with at least one BMI measurement also had a WC measurement. The most common median BMI category was overweight (36.9%) and median WC was 95.0 centimetres (IQR = 21.5).Conclusions: This study reports the documentation of obesity and overweight in select Canadian primary care EMRs infrequently recorded WC when compared to BMI. Future studies should examine the frequency and categories of anthropometric measurements in people with commonly managed chronic conditions and whether BMI and WC inputs are missing at random. Trial registration: Not applicable for this study.