Table 3: Prevalence ratios for osteoarthritis adjusted for age and sex, by location of residence, BMI and smoking status.
| Characteristic* | PR (95% CI) | p value |
|---|---|---|
| Location (n = 201 718) | ||
| Urban = ref | 1.00 | — |
| Rural | 0.99 (0.96–1.01) | 0.3 |
| BMI group (n = 136 765) | ||
| Underweight (< 18) | 1.11 (1.04–1.17) | < 0.001 |
| Normal (18–24) = ref | 1.00 | — |
| Overweight (25–29)† | 1.04 (1.01–1.07) | 0.004 |
| Obese (> = 30)‡ | 1.14 (1.11–1.17) | < 0.001 |
| Smoking n = 85 705 | ||
| Never = ref | 1.00 | — |
| Past | 0.98 (0.95–1.01) | 0.2 |
| Current | 0.90 (0.86–0.94) | < 0.001 |
Note: BMI = body mass index, CI = confidence interval, PR = prevalence ratio. *Location data missing for 5 892 (2.8%) patients; BMI data missing for 7 388 (25%) patients with osteoarthritis and 64 910 (36.5%) patients without osteoarthritis; smoking data missing for 15 980 (54%) patients with osteoarthritis and 105 925 (59.5%) patients without osteoarthritis. †p < 0.01. ‡p < 0.001.