Abstract

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Background
Keywords
Findings
Authors

Background

This study compares waist circumference (WC) measured using the World Health Organization (WHO) and National Institutes of Health (NIH) protocols to determine if the results differ significantly, and whether equations can be developed to allow comparison between WC taken at the two different measurement sites.

Data and Methods

Valid WC measurements using the WHO and NIH protocols were obtained for 6,306 respondents aged 3 to 79 from Cycle 2 of the Canadian Health Measures Survey. Linear regression was used to identify factors associated with the difference between the NIH and WHO values. Separate prediction equations by sex were generated using WC_NIH as the outcome and WC_WHO and age as independent variables. Sensitivity and specificity were calculated to examine whether health risk based on the WC_WHO and on WC_NIH predicted measurements agreed with estimates based on WC_NIH actual measured values.

Results

For adults and children, WC_NIH significantly exceeded WC_WHO (1.0 cm for boys, 2.1 cm for girls, 0.8 cm for men and 2.2 cm for women). Predicted NIH values were statistically similar to measured values.  Sensitivity (86% to 98%) and specificity (70% to 100%) values for health risk category based on the NIH predicted values were very high, meaning that respondents would be appropriately classified when compared with actual measured values.

Interpretation

The prediction equations proposed in this study can be applied to historical datasets to compare estimates based on WC data measured using the WHO and NIH protocols.

Keywords

Body composition, central obesity, cross-over study, direct measure, sensitivity, specificity

Findings

Waist circumference (WC) is an important independent measure in the assessment of obesity-related health risk. The 2003 Canadian Guidelines for Weight Classification in Adults recommended that WC be measured on all persons with a body mass index (BMI) between 18.5 and 34.9 kg/m², using the World Health Organization (WHO) measurement protocol. In 2006, based on recommendations from an expert panel, the Canadian clinical practice guidelines on the management and prevention of obesity in adults and children suggested that practitioners use the National Institutes of Health (NIH) method to measure WC. Two years later, the Canadian Society for Exercise Physiology (CSEP) adopted the NIH method as part of the measurement protocols in the Canadian Physical Activity and Fitness Lifestyle Approach. [Full Text]

Authors

Jennifer Patry-Parisien (613-951-6010; jennifer.patry-parisien@statcan.gc.ca) and Shirley.Bryan (613-951-4968; shirley.bryan@statcan.gc.ca) are with the Health Statistics Division, and Margot Shields was formerly with the Health Analysis Division at Statistics Canada, Ottawa, Ontario, K1A 0T6.