Table 1.
Characteristics of incident OA patients and matched controls at the index date
| Characteristics | Incident OA (n = 221 807) | Controls (n = 221 807) | Unadjusted ORa (95% CI) |
|---|---|---|---|
| Age, mean (s.d.), years | 61.05 (13.17) | 60.88 (13.31) | |
| Age (men), mean (s.d.), years | 60.71 (12.85) | 60.54 (12.97) | |
| Age (women), mean (s.d.), years | 61.30 (13.40) | 61.12 (13.55) | |
| Age (years), n (%) | |||
| <40 | 12 266 (5.53) | 13 018 (5.87) | NA |
| 40–49 | 30 809 (13.89) | 31 673 (14.28) | NA |
| 50–59 | 60 287 (27.18) | 59 606 (26.87) | NA |
| 60–69 | 60 442 (27.25) | 59 294 (27.02) | NA |
| 70–79 | 40 879 (18.43) | 40 418 (18.22) | NA |
| 80–89 | 15 926 (7.18) | 15 815 (7.13) | NA |
| >90 | 1198 (0.54) | 1353 (0.61) | NA |
| Gender, n (%) | |||
| Men | 93 895 (42.33) | 93 895 (42.33) | NA |
| Women | 127 912 (57.67) | 127 912 (57.67) | NA |
| BMI (kg/m2), n (%) | |||
| BMI, mean (s.d.) | 28.28 (5.62) | 26.62 (4.98) | |
| <18.5 (underweight) | 3039 (1.37) | 4810 (2.17) | 0.85 (0.82 0.90)* |
| 18.5–24.9 (normal) | 63 547 (28.65) | 86 620 (39.06) | Reference |
| 25.0–29.9 (overweight) | 82 734 (37.30) | 83 013 (37.44) | 1.38 (1.36, 1.40)* |
| ≥30 (obese) | 72 487 (32.68) | 47 294 (21.33) | 2.14 (2.11, 2.18)* |
| Alcohol consumption (units/week), n (%) | |||
| Never | 44 117 (19.89) | 41 392 (18.67) | Reference |
| Ex-drinker | 6033 (2.72) | 5349 (2.41) | 1.04 (1.00, 1.08) |
| Current, 1–9 | 77 588 (34.98) | 80 381 (36.25) | 0.89 (0.88, 0.91)* |
| Current, ≥10 | 43 186 (19.47) | 43 226 (19.49) | 0.92 (0.91, 0.95)* |
| Current, unknown | 50 883 (22.94) | 51 409 (23.18) | 0.92 (0.91, 0.94)* |
| Smoking status, n (%) | |||
| Never smoked | 117 536 (52.99) | 123 882 (55.86) | Reference |
| Ex-smoker | 62 571 (28.21) | 57 668 (26.00) | 1.15 (1.14, 1.17)* |
| Current smoker | 41 700 (18.80) | 40 237 (18.14) | 1.10 (1.08, 1.12)* |
| Joints involved, n (%) | |||
| Hip | 25 091 (11.31) | ||
| Knee | 54 841 (24.72) | ||
| Wrist/Hand | 13 255 (5.97) | ||
| Ankle/Foot | 5311 (2.39) | ||
| Unspecified | 158 620 (71.51) |
a
Matched by gender, age, practice, and index date. *P-value <0.05. BMI, Body mass index; NA, not applicable.