Table 2.
Relative risk (RR) and 95% confidence intervals (CI) for exacerbation of low back pain (LBP) within the occupational groups by severity of disease at recruitment
| Severity of LBP at recruitment by occupational group | Number exacerbated (total number) | Incident cases (IR) for 3 years | Incident cases (IR) per year | RR (95% CI) | P |
|---|---|---|---|---|---|
| Administrative | |||||
| Category 1 | 1274 (61046) | 2.1% | 0.7% | 1 | |
| Category 2 | 123 (4612) | 2.7% | 0.9% | 1.28 (1.07–1.53) | < 0.01 |
| Category 3 | 79 (1066) | 7.4% | 2.5% | 3.55 (2.85–4.42) | < 0.0001 |
| Car drivers | |||||
| Category 1 | 68 (3254) | 2.1% | 0.7% | 1 | |
| Category 2 | 10 (333) | 3.0% | 1.0% | 1.48 (0.75–2.76) | 0.32 |
| Category 3 | 6 (60) | 10.0% | 3.3% | 4.79 (2.16–10.59) | < 0.002 |
| Truck drivers | |||||
| Category 1 | 99 (9689) | 1.0% | 0.3% | 1 | |
| Category 2 | 13 (473) | 2.7% | 0.9% | 2.69 (1.52–4.76) | < 0.002 |
| Category 3 | 4 (66) | 6.1% | 2.0% | 5.93 (2.25–15.64) | < 0.005 |
| Total drivers | |||||
| Category 1 | 167 (12943) | 1.3% | 0.4% | 1 | |
| Category 2 | 23 (806) | 2.9% | 1.0% | 2.21 (1.44–3.40) | < 0.001 |
| Category 3 | 10 (126) | 7.9% | 2.6% | 6.15 (3.33–11.36) | < 0.0001 |
| All subjects | |||||
| Category 1 | 1441 (73989) | 1.95% | 0.65% | 1 | |
| Category 2 | 146 (5418) | 2.69% | 0.90% | 1.38 (1.17–1.64) | < 0.0001 |
| Category 3 | 89 (1192) | 7.47% | 2.49% | 3.83 (3.12–4.71) | < 0.0001 |
Category 1 – No history of LBP
Category 2 – Mild LBP
Category 3 – LBP with mild clinical/radiographic findings
Bold data already signifies a p < 0.05 i.e. significant finding