Table 2.

Univariable logistic regression of acute back pain and multivariable logistic regression of acute back pain, adjusted for significantly associated covariates

	Univariable analysis			Multivariable analysis
	N	Crude OR (95% CI)	P value	Adjusted OR (95% CI)	P value
WIMD 2014 quintile	14,359
Least deprived		Reference category
2		1.05 (0.94, 1.17)	0.405	1.03 (0.92, 1.16)	0.611
3		1.03 (0.93, 1.15)	0.539	1.00 (0.89, 1.13)	0.940
4		1.00 (0.89, 1.12)	0.958	0.93 (0.82, 1.05)	0.261
Most deprived		0.91 (0.81, 1.03)	0.138	0.86 (0.76, 0.98)	0.029
Age	14,359
16–24		Reference category
25–44		1.69 (1.49, 1.93)	< 0.001	1.64 (1.42, 1.90)	< 0.001
45–64		1.84 (1.62, 2.09)	< 0.001	1.73 (1.50, 1.99)	< 0.001
65+		1.44 (1.26, 1.65)	< 0.001	1.49 (1.27, 1.73)	< 0.001
Gender	14,359
Male		Reference category
Female		1.08 (1.00, 1.16)	0.040	1.01 (0.94, 1.10)	0.761
Educational attainment	13,398
No qualification		Reference category
Degree equivalent or higher		1.21 (1.07, 1.36)	0.002	1.28 (1.12, 1.47)	< 0.001
Other qualifications		1.22 (1.11, 1.34)	< 0.001	1.32 (1.18, 1.47)	< 0.001
BMIa	13,387
Less than 18.5		0.65 (0.49, 0.87)	0.004	0.79 (0.58, 1.07)	0.127
18.5 to under 25		Reference category
25 to under 30		1.20 (1.11, 1.31)	< 0.001	1.14 (1.04, 1.25)	0.004
30 and over		1.33 (1.21, 1.46)	< 0.001	1.20 (1.08, 1.33)	0.001
Mental health (SF-36)	14,359
Above averageb		Reference category
Below averagec		1.60 (1.49, 1.72)	< 0.001	1.59 (1.47, 1.72)	< 0.001
Vigorous exercise	13,757
0–2 days per week		Reference category
3–5 days		0.83 (0.73, 0.94)	0.03	0.91 (0.80, 1.03)	0.156
6–7 days		0.83 (0.68, 1.02)	0.077	0.91 (0.74, 1.13)	0.406

^aBody mass index

^bMental health score above the average of the general population

^cMental health score below the average of the general population