title: Self-reported waist circumference compared with the 'Waist Watcher' tape-measure to identify individuals at increased health risk through intra-abdominal fat accumulation.
abstract: We evaluated the accuracy of self-reported home-assessed and self-measured waist circumference in 101 men and eighty-three women aged 28-67 years. The main outcome measures were subjects' self-reported and self-measured waist circumference, and self-classification according to the previously defined waist action level 1 (940 mm in men, 800 mm in women) and action level 2 (1020 mm in men, 880 mm in women), and waist circumference measured by the investigator using the 'Waist Watcher' tape-measure, as the reference method. The mean errors (95% CI limits of agreement) for subjects' self-reported waist circumference (self-reported minus reference; mm) were -67 (95% CI -210, 77) in men and -43 (95% CI -211, 123) in women, and for self-measured waist circumference (mm) using the 'Waist Watcher' (self-measured minus reference) were -5 (95% CI -62, 52) in men and -4 (95% CI -50, 42) in women. The proportions of subjects classified into waist action level 1 or action level 2 by the investigator were used as the reference method. Self-reported waist circumference of men and women respectively would be classified correctly in different categories based on action level 1 with sensitivities of 58.3 and 78.7%, and specificities of 92.5 and 91.7%, and action level 2 with sensitivities of 35.3 and 44.9%, and specificities of 98.5 and 90.7%. Using the 'Waist Watcher' with different colour bands based on the action levels, male and female subjects respectively classified themselves into correct categories according to action level 1 with sensitivities of 100 and 95.7%, and specificities of 95.1 and 97.2%, and according to action level 2 with sensitivities of 97.1 and 100%, and specificities of 100% for both sexes. Only 2% of the sample misclassified themselves into the wrong categories according to waist circumference action levels. In conclusion, people tend to underestimate their waist circumference, but the 'Waist Watcher' tape-measure offers advantages over self-reported home-assessed measurement, and may be used as a screening tool for self-classifying the risk of ill health through intra-abdominal fat accumulation.
authors.affiliation: University Department of Human Nutrition, Royal Infirmary, Glasgow, UK. t.s.han@clinmed.gla.ac.uk
authors.forename: T S
authors.initials: TS
authors.lastname: Han
authors.forename: M E
authors.initials: ME
authors.lastname: Lean
mesh_terms: D000005:Abdomen; D000328:Adult; D000368:Aged; D000886:Anthropometry; D001824:Body Constitution; D015992:Body Mass Index; D003327:Coronary Disease / Q000517:prevention & control; D004867:Equipment Design; D005069:Evaluation Studies as Topic; D005260:Female; D006293:Health Promotion; D006801:Humans; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000517:prevention & control; D011446:Prospective Studies; D016353:Self-Examination; D012680:Sensitivity and Specificity