Table 3. Agreement between BMI and body fat percentage for defining obesity in Brazil, 3,822 male firefighters, 2009.
| Body fat % > 25% | Agreement: 85.8% (95%CI 84.7–86.9) Sensitivity: 47.4% (95%CI 43.4–51.5) Specificity: 93.1% (95%CI 92.2–93.9) Positive likelihood ratio: 6.87 (95%CI 5.90–8.00) Negative likelihood ratio: 0.56 (95%CI 0.52–0.61) Positive predictive value: 56.5% (95%CI 52.0–60.8) Negative predictive value: 90.4% (95%CI 89.3–91.4) | ||||||||
|---|---|---|---|---|---|---|---|---|---|
| Yes | No | Total | |||||||
| N (%) | N (%) | N | |||||||
| BMI ≥ 30 kg/m2 | Yes | N (%) | 288 (7.5%) | 222 (5.8%) | 510 | ||||
| No | N (%) | 319 (8.3%) | 2,993 (78.3%) | 3,312 | |||||
| Total | N | 607 | 3,215 | 3,822 | |||||
| Alternative cut-offs | |||||||||
| Cut-off | 27 kg/m2 | 28 kg/m2 | 29 kg/m2 | ||||||
| Agreement, % (95%CI) | 69.9 (68.5–71.4) | 77.7 (76.4–79.0) | 82.9 (81.7–84.1) | ||||||
| Sensitivity, % (95%CI) | 82.4 (79.1–85.3) | 72.2 (68.4–75.7) | 60.5 (56.4–64.4) | ||||||
| Specificity, % (95%CI) | 67.6 (65.9–69.2) | 78.8 (77.3–80.2) | 87.2 (86.0–88.3) | ||||||
| Positive likelihood ratio, (95%CI) | 2.54 (2.39–2.70) | 3.40 (3.13–3.70) | 4.72 (4.22–5.27) | ||||||
| Negative likelihood ratio, (95%CI) | 0.26 (0.22–0.31) | 0.35 (0.31–0.40) | 0.45 (0.41–0.50) | ||||||
| Positive predictive value, % (95%CI) | 32.4 (30.1–34.8) | 39.1 (36.2–42.0) | 47.1 (43.6–50.7) | ||||||
| Negative predictive value, % (95%CI) | 95.3 (94.4–96.1) | 93.7 (92.8–94.6) | 92.1 (91.1–93.0) | ||||||