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. 2016 Nov 7;60(6):515–525. doi: 10.1590/2359-3997000000220

Table 6. Diagnosis of obesity (body fat percentage ≥ 25) based on body mass index. Analysis stratified by age class (n = 3,822 male firefighters).

  Age (completed years)

≤ 30 years N = 329 31–40 years N = 2,521 > 40 years N = 972
BMI ≥ 27 kg/m2      

Agreement, % (95%CI) 81.2 (76.5–85.2) 69.6 (67.8–71.4) 67.0 (63.9–69.9)
Sensitivity, % (95%CI) 80.0 (61.4–92.3) 81.6 (77.5–85.2) 84.7 (78.4–89.8)
Specificity, % (95%CI) 81.3 (76.4–85.5) 67.3 (65.3–69.3) 63.2 (59.8–66.6)
Positive likelihood ratio, (95%CI) 4.27 (3.18–5.74) 2.50 (2.31–2.69) 2.30 (2.06–2.57)
Negative likelihood ratio, (95%CI) 0.25 (0.12–0.50) 0.27 (0.22–0.34) 0.24 (0.17–0.35)
Positive predictive value, % (95%CI) 30.0 (20.3–41.3) 32.5 (29.6–35.4) 32.8 (28.4–37.4)
Negative predictive value, % (95%CI) 97.6 (94.8–99.1) 95.0 (93.8–96.0) 95.1 (92.9–96.8)

BMI ≥ 28 kg/m2      

Agreement, % (95%CI) 85.7 (81.5–89.3) 77.9 (76.2–79.5) 74.6 (71.7–77.3)
Sensitivity, % (95%CI) 53.3 (34.3–71.7) 71.7 (67.1–76.1) 76.5 (69.4–82.6)
Specificity, % (95%CI) 89.0 (84.9–92.3) 79.1 (77.3–80.8) 74.2 (71.0–77.2)
Positive likelihood ratio, (95%CI) 4.83 (3.04–7.69) 3.43 (3.10–3.80) 2.96 (2.57–3.42)
Negative likelihood ratio, (95%CI) 0.52 (0.36–0.77) 0.36 (0.31–0.42) 0.32 (0.24–0.42)
Positive predictive value, % (95%CI) 32.7 (19.9–47.5) 39.8 (36.2–43.4) 38.6 (33.4–44.0)
Negative predictive value, % (95%CI) 95.0 (91.8–97.2) 93.6 (92.3–94.7) 93.7 (91.5–95.5)

BMI ≥ 29 kg/m2      

Agreement, % (95%CI) 89.4 (85.5–92.5) 83.5 (82.0–84.9) 79.4 (76.7–81.9)
Sensitivity, % (95%CI) 46.7 (28.3–65.7) 59.5 (54.5–64.3) 65.3 (57.6–72.4)
Specificity, % (95%CI) 93.6 (90.3–96.1) 88.1 (86.6–89.4) 82.4 (79.6–85.0)
Positive likelihood ratio, (95%CI) 7.34 (4.11–13.1) 4.99 (4.33–5.74) 3.71 (3.08–4.47)
Negative likelihood ratio, (95%CI) 0.57 (0.41–0.80) 0.46 (0.41–0.52) 0.42 (0.34–0.52)
Positive predictive value, % (95%CI) 42.4 (25.5–60.8) 49.0 (44.5–53.5) 44.0 (37.8–50.4)
Negative predictive value, % (95%CI) 94.6 (91.4–96.9) 91.9 (90.6–93.0) 91.8 (89.6–93.7)

BMI ≥ 30 kg/m2      

Agreement, % (95%CI) 91.2 (87.6–94.0) 86.6 (85.2–87.9) 82.2 (79.6–84.6)
Sensitivity, % (95%CI) 33.3 (17.3–52.8) 48.4 (43.5–53.4) 47.6 (39.9–55.4)
Specificity, % (95%CI) 97.0 (94.4–98.6) 93.9 (92.8–94.9) 89.5 (87.2–91.6)
Positive likelihood ratio, (95%CI) 11.1 (4.88–25.1) 7.93 (6.53–9.64) 4.55 (3.52–5.88)
Negative likelihood ratio, (95%CI) 0.69 (0.56–0.74) 0.55 (0.50–0.60) 0.58 (0.51–0.68)
Positive predictive value, % (95%CI) 52.6 (28.9–75.6) 60.4 (54.9–65.8) 49.1 (41.2–57.0)
Negative predictive value, % (95%CI) 93.5 (90.2–96.0) 90.4 (89.1–91.6) 89.0 (86.6–91.0)