Neck circumference as a simple screening measure for identifying overweight and obese patients

Objective: There are numerous methods of assessing overweight and obesity. We undertook an observational study to test a method of identifying overweight or obese patients solely by measuring the circumference of the neck. Research Methods and Procedures: A test sample and a second validation sample included 979 subjects (460 men and 519 women), who visited a family medicine clinic in a southern Israeli urban district for any reason between the randomly chosen months of January and September 1998. Main outcome included neck, waist, and hip circumferences; body mass index (BMI); and waist:hip ratio measures. Results: Pearson's correlation coefficients indicated a significant association between neck circumference (NC) and: BMI (men, r=0.83; women, r=0.71; each, p<0.0001), age (men, r=0.33; women, r=0.36; each, p<0.0001), weight (men, r=0.7; women, r=0.81; each, p<0.0001), waist circumference (men, r=0.86; women, r=0.85; each, p<0.0001), hip circumference (men, r=0.62; women, r=0.56; each, p<0.0001), and waist:hip ratio (men, r=0.66; women, r=0.87; each, p<0.0001). NC greater than or equal to 37 cm for men and greater than or equal to 34 cm for women were the best cutoff levels for determining the subjects with BMI greater than or equal to 25.0 kg/m(2) using the receiver output curve analysis. In the validation unrelated group, the test characteristics were excellent with 98% sensitivity, 89% specificity, and 94% accuracy for men, and 100% sensitivity, 98% specificity, and 99% accuracy for women. NC greater than or equal to 39.5 cm for men and greater than or equal to 36.5 cm for women were the best cutoff levels for determining the subjects with BMI greater than or equal to 30 kg/m(2) using the receiver output curve analysis. In the validation unrelated group, the test characteristics were excellent with 93% sensitivity, 90% specificity, and 91% accuracy for men, and 93% sensitivity, 98% specificity, and 97% accuracy for women. Discussion: NC measurement is a simple and time-saving screening measure that can be used to identify overweight and obese patients. Men with NC <37 cm and women with NC <34 cin are not to be considered overweight. Patients with NC greater than or equal to 37 cm for men and greater than or equal to 34 cm for women require additional evaluation of overweight or obesity status.