Identification of obesity in patients with type 2 diabetes from Australian primary care: the NEFRON-5 study.

RESEARCH DESIGN AND METHODS — The National Evaluation of the Frequency of Renal Impairment cO-ex i s t ing wi th NIDDM (NEFRON) study was an incident-driven, clustered, stratified survey of 3,893 patients with type 2 diabetes in the Australian primary care setting. Investigator selection and patient characteristics are described elsewhere (appendix 1 [available at http://care.diabetesjournals.org]) (2). Caucasian individuals with a BMI 25.0–29.9 kg/m were classified as overweight, while those with a BMI 30.0 kg/m were classified as obese (3). In Asian patients, overweight and obese categories were defined by a BMI 23 and 25 kg/m, respectively (4). Waist circumference was measured halfway between the lower border of the ribs and the iliac crest on a horizontal plane. Men with a waist circumference between 94.0 and 101.9 cm and women with a waist circumference between 80.0 and 87.9 cm were classified as overweight. A waist circumference 102.0 cm in men and 88.0 cm in women classified abdominal obesity, except in patients of Asian ethnicity where the World Health Organization Expert Committee on Obesity in Asian and Pacific populations has recommended that a waist circumference of 90.0 cm for men and 80.0 cm for women can be used for identifying individuals with abdominal obesity (5). Practitioners were asked whether they currently perceived their patient as underweight, ideal weight, overweight, or obese. No instruction was provided on how to classify patients. The predictive value for variables associated with the perception of obesity by practitioners were deduced from the area under the receiver operating characteristic curve.