Table 3.

Relative risk (RR) and p-values for low back pain (LBP) among different occupational groups by severity of disease at recruitment

Group comparison	Category 1	Category 2	Category 3
Car driver vs. administrative	1.00 (NS)	1.13 (NS)	1.35 (NS)
Truck driver vs. administrative	0.49 (0.40–0.60, p < 0.001)	1.03 (NS)	0.82 (NS)
Total drivers vs. administrative	0.62 (0.527–0.726, p < 0.001)	1.07 (NS)	1.07 (NS)
Truck driver vs. car driver	0.49 (NS)	0.92 (NS)	0.61 (NS)

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