Body mass index estimation and measurement by healthcare professionals

Background: Severe obesity has increased more than three-fold in prevalence over the past fifteen years in Europe and the United States. Correctly identifying severe obesity permits access to mortality-reducing interventions. We aimed to determine the accuracy of healthcare professionals (HCPs) in recognising severe obesity and the frequency of body mass index (BMI) assessment by HCPs. Methods: We performed two cross-sectional surveys: one of 206 HCPs in Ireland and Canada and another of 515 Irish hospital healthcare records. The first survey evaluated BMI estimation from photographs and the second examined recording of weight and height during outpatient clinic visits. Results: HCPs underestimated the BMI of severely obese people by an average of 22% to 39%. For a patient with a BMI of 52 kg/m2, 35.4% of family physicians appreciated that the patient was severely obese (BMI > 40 kg/m2) compared with 81.0% of endocrinologists. During clinic visits only 18.1% (n = 75), 1% (n = 4) and 0% (n = 0) of patients had their respective weights, heights and BMIs recorded. Conclusions: HCPs frequently fail to recognise severe obesity from photographs and, in our centre, do not routinely record weight or height. Whether patient outcomes can be improved by measuring weight and height during every HCP encounter warrants further study.