Table 1.
Mean (SD) self-measured waist circumference and objectively measured waist circumference and their mean differences (95% CI) stratified by anthropometric, demographic and behavioural characteristics
| Categories | n | SMWC | OMWC | SMWC- OMWC mean (95% CI) a | P -value b | ||||
|---|---|---|---|---|---|---|---|---|---|
| Mean | SD | Mean | SD | Mean | Low | High | |||
| Overall | 617 | 102.6 | 10.1 | 96.6 | 9.7 | 6.0 | 6.4 | 5.6 | <0.01b |
| Agec | |||||||||
| Younger | 309 | 103.9 | 10.6 | 97.4 | 9.8 | 6.4 | 6.9 | 5.9 | 0.02b |
| Older | 308 | 101.3 | 9.4 | 95.8 | 9.6 | 5.5 | 6.1 | 5.0 | |
| Education | |||||||||
| Primary | 201 | 103.5 | 11.2 | 96.9 | 11.1 | 6.6 | 7.3 | 5.9 | 0.03b |
| Secondary | 285 | 102.7 | 9.8 | 96.8 | 9.3 | 5.9 | 6.5 | 5.4 | |
| College | 128 | 100.8 | 8.7 | 95.6 | 8.2 | 5.2 | 6.0 | 4.4 | |
| Body mass indexd | |||||||||
| Normal | 84 | 93.7 | 6.1 | 87.3 | 6.0 | 6.4 | 7.5 | 5.3 | 0.56 |
| Overweight | 333 | 100.3 | 7.6 | 94.5 | 7.3 | 5.8 | 6.3 | 5.3 | |
| Obese | 200 | 110.1 | 10.3 | 104.0 | 9.4 | 6.1 | 6.8 | 5.4 | |
| Dietary behavioure | |||||||||
| Yes | 47 | 99.3 | 9.1 | 94.1 | 9.1 | 5.2 | 6.6 | 3.8 | 0.23 |
| No | 531 | 102.7 | 10.1 | 96.7 | 9.7 | 6.1 | 6.5 | 5.7 | |
| Smoking behaviourf | |||||||||
| Yes | 126 | 104.3 | 11.5 | 97.9 | 10.7 | 6.4 | 7.1 | 5.6 | 0.33 |
| No | 487 | 102.1 | 9.7 | 96.2 | 9.4 | 5.9 | 6.3 | 5.5 | |
| Physical activityg | |||||||||
| Yes | 383 | 101.8 | 9.8 | 96.1 | 9.4 | 5.8 | 6.3 | 5.3 | 0.26 |
| No | 230 | 103.8 | 10.6 | 97.4 | 10.3 | 6.4 | 7.0 | 5.8 | |
| Sedentary behaviourh | |||||||||
| Yes | 542 | 102.8 | 10.1 | 96.8 | 9.8 | 6.0 | 6.4 | 5.6 | 0.74 |
| No | 69 | 100.4 | 10.0 | 94.5 | 9.0 | 5.8 | 6.9 | 4.7 | |
Abbreviations: OMWC, objectively measured waist circumference; SMWC, self-measured waist circumference.
aDifference calculated as self-measured minus objectively WC values, note that negative and positive values indicates under and over -estimation, respectively.
bSignificant differences (P < 0.05).
cAge groups: younger ≤44.07 years and older >44.07 years.
dBody mass index: normal <25.0 kg/m2, overweight ≥25.0 to <29.9 kg/m2, obese ≥30.0 kg/m2.
eDiet: Yes: meeting recommendations of at least two pieces of fruit and 200 g of vegetables intake per day; No: not meeting these recommendations.
fSmoking behaviour: Yes: current smoker: No: not current smoker.
gPhysical activity: Yes: meeting the national recommendations of being physically active (≥30 minutes moderate-intensity physical activity), No: not meeting these recommendations.
hSedentary Behaviour: Yes: sedentary (≥2 hours per day activities with an energy expenditure of under 2 METs); No: not meeting these recommendations.