Table 2. Occupational odds in knee osteoarthritis by different subgroups.
| Subgroups | N of studies/participants | Summary meta-analysis, OR (95% CI) | Heterogeneity, % (P value) | |
|---|---|---|---|---|
| Study design | ||||
| Case-control | 25/17,765 | 1.58 (1.18, 2.11) | 96.9% (<0.01) | |
| Cross-sectional | 32/143,364 | 1.54 (1.38, 1.72) | 88.4% (<0.01) | |
| Cohort | 14/790,216 | 1.45 (1.32, 1.59) | 57.6% (<0.01) | |
| OA definition criteria a | ||||
| Symptomatic | 58/11,178,459 | 1.43 (1.34, 1.53) | 85.8% (<0.01) | |
| Radiographic | 13/39,490 | 1.57 (1.24, 1.98) | 97.1% (<0.01) | |
| Gender | ||||
| Male | 29/471,779 | 1.61 (1.42, 1.83) | 78.7% (<0.01) | |
| Female | 18/174,077 | 1.35 (1.20, 1.51) | 64.6% (<0.01) | |
| Occupational exposure time | ||||
| Current job | 19/632,683 | 1.45 (1.30, 1.62) | 71.4% (<0.01) | |
| Longest-held job | 24/40,381 | 1.45 (1.31, 1.60) | 77.0% (<0.01) | |
| Lifetime | 13/20,172 | 1.65 (1.30, 2.09) | 89.8% (<0.01) | |
| Region | ||||
| Europe | 38/895,716 | 1.56 (1.31, 1.87) | 96.1% (<0.01) | |
| North America | 10/21,598 | 1.47 (1.19, 1.82) | 88.1% (<0.01) | |
| Oriental | 14/26,201 | 1.45 (1.27, 1.65) | 70.7% (<0.01) | |
| Middle East | 5/3,011 | 1.25 (1.04, 1.49) | 50.1% (0.09) | |
| Rest of the world | 4/4,819 | 1.47 (0.71, 3.04) | 93.7% (<0.01) | |
| Setting | ||||
| Community | 43/385,536 | 1.38 (1.27, 1.49) | 78.2% (<0.01) | |
| Hospital | 7/249,758 | 1.39 (1.22, 1.58) | 79.6% (<0.01) | |
| Industry | 16/315,192 | 1.84 (1.52, 2.24) | 84.1% (<0.01) | |
| Methodological quality | ||||
| Low b | 55/383,937 | 1.57 (1.37, 1.79) | 95.5% (<0.01) | |
| High | 16/567,408 | 1.39 (1.19, 1.63) | 82.6% (<0.01) | |
| Confounding | ||||
| Unadjusted analysis | 26/31,577 | 1.54 (1.42, 1.67) | 82.8% (<0.01) | |
| Adjusted analysis | 45/919,768 | 1.44 (1.11, 1.85) | 97.4% (<0.01) |
Bold values denote statistical significance at the P < 0.05 level.
Subgroup analysis to show if heterogeneity is related to certain study characteristics. The percentage values for heterogeneity were calculated using the I2 test and the P values are from the Cochran Q test.
Reference group is non-exposed workers or those exposed to the lowest level possible.
a
Symptomatic osteoarthritis defined as symptomatic osteoarthritis with or without radiographic measures. Radiographic osteoarthritis defined as radiographic measures only.
b
Studies with a Newcastle Ottawa score < 7 were defined as low methodological quality.