Accuracy of doctors' anthropometric measurements in general practice

There is increasing pressure on general practitioners (GPs) to identify patients with abdominal obesity in order to reduce the life-threatening consequences of this condition in the population. We aimed to confirm previous findings on the inaccuracy of anthropometric measurements performed by GPs in an academic primary care clinic and to assess the effect of theoretical training to improve the quality of these measurements.

This cross-sectional study involved 26 GPs from private practices in Geneva, Switzerland. They were asked to measure weight, height, waist and hip circumference on ten volunteers within their practice. Two trained research assistants repeated the measurementss after the GPs ("gold standard"). The GPs were then randomised to receive information detailing the correct method for taking measurements (intervention, 14 doctors) or simple information about obesity (control, 12 doctors). Measurements were repeated a few weeks later. Measurement error was computed by comparing the GPs' values with the average value of two measurements taken in turn by the research assistants, and agreement was examined by Bland-Altman plots. The GPs' skills were assessed through auto-questionnaire and direct observation.

All measurements except height were prone to measurement error, the least affected being weight (and therefore body mass index [BMI]). Following training, measurement errors were slightly less prominent in the intervention group. GPs' skills in measuring waist and hip circumference were frequently assessed as inadequate, but showed improvement after training.

Without proper training, priority should be given to using classical anthropometric measurements (i.e. weight, height and BMI determination) in daily practice.