Table 1.
Relative risk of undergoing knee replacement for osteoarthritis based on body mass index category, compared to persons with normal body mass index (18.5–24.9 kg/m2), by age and gender
| Age (years) | BMI category | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Normal # (18.5–24.9 kg/m2) | Overweight (25.0–29.9 kg/m2) | Obese class 1 (30.0–34.9 kg/m2) | Obese class 2 (35.0–39.9 kg/m2) | Obese class 3 (≥ 40.0 kg/m2) | ||||||
| F | M | F | M | F | M | F | M | F | M | |
| 45–54 | 1.0 | 1.0 | 3.1 | 1.8 | 7.5 | 3.2 | 12.2 | 5.4 | 24.9 | 7.0 |
| 55–64 | 1.0 | 1.0 | 3.1 | 2.1 | 4.7 | 3.4 | 8.4 | 4.5 | 17.3 | 5.8 |
| 65–74 | 1.0 | 1.0 | 2.1 | 1.8 | 3.6 | 2.3 | 4.9 | 2.5 | 5.5 | 3.9 |
| 75–84 | 1.0 | 1.0 | 1.8 | 1.4 | 2.1 | 1.6 | 2.4 | 2.2 | 2.2 | 1.5 |
Note: BMI, body mass index; kg, kilograms; m, metres; F, female; M, male. Note that comparisons for the underweight body mass index category and the 18–24, 25–34, 35–44 and ≥85 year age categories are not presented because numbers available for analysis were small and the estimates were imprecise.
#
Reference body mass index.