Summary of findings from all identified evidence describing the number of studies (N) and number of participants (n) in each of the outcome (body area), study design, exposure assessment and study findings by categories
| Total | Study design | Exposure assessment | Study findings | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Cross-sectional case–control | Cross-sectional observational | Longitudinal observational | Self-reports | Observations | Objective | Meta-analysis | Positive* (significant) | Negative† (significant) | Non-significant | No data reported | |||
| Low-back | N | 39 | 4 | 31 | 4 | 37 | 1 | 1 | 16‡ | 9 | – | 8 | 6 |
| n | 82 291 | 9210 | 6364 | 9435 | 81 863 | 401 | 27 | 54 392 ‡ | 9239 | – | 7330 | 11 330 | |
| Lower extremity | N | 14 | 3 | 9 | 2 | 13 | 1 | – | – | 8 | 1 | 4 | 4 |
| n | 31 924 | 5081 | 24 147 | 2696 | 31 903 | 21 | – | – | 24 502 | 759 | 6192 | 2749 | |
| Upper extremity | N | 18 | 5 | 14 | 1 | 18 | 1 | 1 | – | 4 | 1 | 9 | 10 |
| n | 25 708 | 1783 | 22 427 | 1498 | 25 251 | 401 | 56 | – | 2602 | 529 | 4647 | 21 882 | |
| All areas | N | 8 | 1 | 6 | 1 | 8 | – | – | – | 3 | 1 | 2 | 2 |
| n | 3114 | 12 | 1604 | 1498 | 3114 | – | – | – | 1960 | 433 | 231 | 490 | |
| Total§ | N | 49 | 7 | 37 | 5 | 45 | 2 | 2 | NA | NA | NA | NA | NA |
| n | 88 158 | 12 632 | 64 893 | 10 633 | 87 653 | 422 | 83 | NA | NA | NA | NA | NA | |
*Substantial standing being associated with higher prevalence of symptoms.
†Substantial standing being associated with lower prevalence of symptoms.
‡Pooled OR (with 95% CI) of 1.31 (1.10 to 1.56).
§Two articles reported on data from the same study, for which the n in the article with the highest number of participants was used.
n, number of participants; N, number of studies; NA, not available.