Table 5 Osteoarthritis of the hip and climbing stairs or ladders
| Reference | Study population | Age (years) | Participation rate | Exposure measured by: | Diagnostic criteria | Adjusted for/matched by: | Comparisons | Result, OR (95% CI) | Design | Quality of the study (+, ++, +++); strength/weakness |
| Croft 199216 | Cases: 245 with hip OA Controls: 294 without hip OA (males) | 60–75 | 68% | Blinded interview Occupational history Specified physical activity | All JSN <2.5 mm severe <1.5 mm examined by urography | Age, sport, BMI | Climbing ladders | Severe cases (<1.5 mm) | Case-control | +++ Strength: high number of participants. Well described design and material. Use of intravenous urograms avoids risk of selection bias. Occupational history with specification of different physical activities. Weakness: number of severe cases relatively small. Exposure measurement: lift >25.4 kg, frequency not explained (risk of misclassification) |
| 1–19 years | 0.8 (0.3 to 1.8) | |||||||||
| ⩾20 years | 1.6 (0.7 to 3.8) | |||||||||
| Climbing >30 stairs >1 year vs <1 year | 1.2 (0.6 to 2.5) | |||||||||
| Vingaard 199728 | Cases: 273 females with THR from 4 areas of Sweden Controls: 273 females, random sample from same areas | 50–70 | 90% | Number of stairs during age 16–50 years Measured by interview | THR | Age, BMI, sports activity, number of children, hormone therapy | Climbing stairs vs low exposure | Relative risk | Case-control | ++ Strength: high participation rate. Occupational history by interview with specification of different physical activities. Adjustment for age, BMI, sports. Weakness: retrospective exposure data (risk of misclassification). Number of stairs only classified as low and high (risk of misclassification) |
| Medium | 1.3 (0.8 to 2.0) | |||||||||
| High | 2.1 (1.2 to 3.6) | |||||||||
| Coggon 199815 | Cases: 210 males, 401 females waiting for THR in 3 English districts Controls: 210 males, 401 females from general practice | 45–91, mean: 70 | 68% 84% of cases, 58% of controls | Interview Occupation held for >1 year from school age Specified physical activity | Waiting for surgery | BMI, hip injury, Heberden’s nodes Matched by age and gender | Climbing stairs >30 flights vs no climbing | Case-control | ++ Strength: high number of participants. Well described study. Exposure collected by interviews with specification of different physical activities. Results adjusted. Weakness: Cases from a waiting list for THR (risk of selection bias). Participation rate relatively low Retrospective exposure measurement (risk of recall bias). Few women in high exposure group | |
| Males | ||||||||||
| <10 years | 1.3 (0.7 to 2.5) | |||||||||
| 10–19 years | 2.3 (1.1 to 4.9) | |||||||||
| ⩾20 years | 1.8 (0.9 to 3.4) | |||||||||
| Females | ||||||||||
| <10 years | 1.4 (0.8 to 2.2) | |||||||||
| 10–19 years | 1.3 (0.4 to 4.0)) | |||||||||
| ⩾20 years | 2.3 (0.8 to 6.3) | |||||||||
| Yoshimura 200029 | Cases: 103 females, 11 males waiting for hip replacement in 2 districts in Japan Controls: 114 from the local population | >45, mean: 64 | 91% | Questionnaire Since leaving school; physical activity in first and main job | Waiting for surgery | Age, gender, residence matched | Climbing stairs >30 flights vs no climbing | Case-control | ++ Strength: same design as Coggon et al and Lau et al. Weakness: few males with OA. Few women reported heavy lifting (>50 kg). Case definition (THR, risk of selection bias). Retrospective exposure data (risk of recall bias). Small number of female participants | |
| First job | 0.9 (0.4 to 2.0) | |||||||||
| Main job | 1.1 (0.5 to 2.1) | |||||||||
| Lau, 200021 | Cases: 30 males, 108 females hospitalised in Hong Kong with hip OA Controls: age and gender matched from general practice in the same region | – | – | Interview Job in which they had worked for the longest period before symptom | THR (71%) Waiting for surgery (10%) Radiographic grade 3–4 OA (19%) | Matched by gender and age | Climbing stairs >15 flights/day vs no climbing | Case-control | ++ Strength: same design as Coggon et al and Yoshimura et al. Weakness: missing age and participation rate. Only a few subjects with THR, especially men. Case definition (THR, risk of selection bias). Retrospective exposure data (risk of recall bias) | |
| Males | 8.7 (1.8 to 42.7) | |||||||||
| Females | 2.5 (1.0 to 5.9) |
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THR, total hip replacement; SHR, standardised hospitalisation ratio; BMI, body mass index (weight/height2); OA, osteoarthritis.
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+, Poor quality score 1–5; ++, medium quality score 6–10; +++, high quality score >10.
