Table 2.
Effect sizes of occupational exposure to develop HOA among different subgroups
| Occupation | Subgroup | Number of studies | RR (95%-CI) | Hetero- geneity (I2) |
Subgroup differences |
|---|---|---|---|---|---|
| Agriculture and forestry | All studies | 12 | 2.81 (2.22–3.55)a | 90% | |
| Disability pension due to HOA | 3 | 3.96 (1.36–11.51)a | 73% | p = 0.72 | |
| THR, no information on disability pension reported | 3 | 2.41 (1.45–4.00)a | 91% | ||
| Diagnosis, but no THR | 6 | 2.60 (1.81–3.72)a | 92% | ||
| Cohort studies | 6 | 2.67 (2.01–3.55)a | 95% | p = 0.51 | |
| Case–control studies | 6 | 3.24 (1.96–5.37)a | 61% | ||
| Construction worker | All studies | 9 | 1.64 (1.28–2.09) | 49% | |
| Disability pension due to HOA | 3 | 2.79 (1.36–5.72) | 59% | p = 0.12 | |
| THR, no information on disability pension reported | 2 | 1.31 (1.02–1.70) | 38% | ||
| Diagnosis, but no THR | 4 | 1.60 (1.36–1.87) | 0% | ||
| Cohort studies | 5 | 1.55 (1.34–1.78) | 0% | p = 0.54 | |
| Case–control studies | 4 | 1.92 (0.97–3.77)a | 73% | ||
| Driving vehicles with whole body vibration | All studies | 8 | 1.52 (1.11–2.08)a | 72% | |
| Disability pension due to HOA | 2 | 2.35 (0.85–6.49)a | 67% | p = 0.18 | |
| THR, no information on disability pension reported | 3 | 1.12 (0.78–1.59) | 51% | ||
| Diagnosis, but no THR | 3 | 1.68 (1.15–2.45) | 50% | ||
| Cohort studies | 5 | 1.42 (0.92–2.21)a | 79% | p = 0.32 | |
| Case–control studies | 3 | 1.87 (1.39–2.52) | 3% | ||
| Metal work | All studies | 6 | 1.54 (1.21–1.97) | 37% | |
| Disability pension due to HOA | 3 | 1.83 (1.15–2.90) | 0% | p = 0.28 | |
| THR, no information on disability pension reported | 1 | 1.10 (0.67–1.80) | - | ||
| Diagnosis, but no THR | 2 | 1.72 (1.10–2.68) | 22% | ||
| Cohort studies | 4 | 1.42 (1.08–1.87) | 0% | p = 0.21 | |
| Case–Control studies | 2 | 2.09 (1.23–3.56) | 0% | ||
| Sales | All studies | 5 | 1.50 (1.01–2.24)b | 38% | |
| Comparable physical demanding occupations | 4 | 1.50 (0.82–2.75) | 51% | p = 0.83 | |
| Heterogeneous physical demanding occupations | 1 | 1.39 (0.95–2.03) | - | ||
| Disability pension due to HOA | 1 | 2.35 (1.19–4.66) | - | p = 0.33 | |
| THR, no information on disability pension reported | 2 | 1.77 (1.00–3.16) | 0% | ||
| Diagnosis, but no THR | 2 | 0.96 (0.37–2.51)c | 65% | ||
| Cohort studies | 2 | 1.67 (1.02–2.72) | 42% | p = 0.51 | |
| Case–Control Studies | 3 | 1.21 (0.54–2.70) | 56% | ||
| Gastronomy | All studies | 4 | 1.44 (0.78–2.66)c | 63% | |
| Cohort studies | 3 | 1.70 (0.92–3.15)a | 63% | p = 0.13 | |
| Case–Control Studies | 1 | 0.60 (0.18–2.02) | - | ||
| Storage and transportation | All studies | 3 | 2.09 (0.88–4.96) | 0% | |
| Cohort study | 1 | 0.92 (0.12–6.99) | - | p = 0.51 | |
| Case–Control-Studies | 2 | 2.50 (0.96–6.52) | 0% | ||
| Food production | All studies | 4 | 2.13 (1.53–2.95)b | 0% | |
| Comparable physical demanding occupations | 3 | 2.22 (1.39–3.54) | 0% | P = 1.00 | |
| Less physical demanding occupations in construction | 1 | 2.04 (1.28–3.24) | - | ||
| Cohort study | 2 | 2.10 (1.48–2.96)b | 0% | p = 0.84 | |
| Case–Control-Studies | 2 | 2.40 (0.64–8.97) | 37% | ||
| Health care | All studies (only cohort studies) | 3 | 1.21 (0.51–2.88)c | 88% | |
| Unskilled or basic level labours | All studies | 3 | 1.89 (1.29–2.77) | 34% | |
| Cohort studies | 2 | 2.15 (1.31–3.54) | 46% | p = 0.28 | |
| Case–Control Studies | 1 | 1.4 (0.77–2.56) | - |
CI confidence interval, HOA hip osteoarthritis, RR relative risk, THR total hip replacement
Pooling not useful due to substantial heterogeneity between results of individual studies (a), clinical heterogeneity in severity of physical demanding occupations (b) or both (c)