Table 3

Generalised linear model examining associations between opioid use and chronic pain

Variables	Categories	OR (95% CIs)	P values
Intercept		0.970 (0.956 to 0.985)	<0.001
Age		1.000 (1.000 to 1.000)	0.112
Pain grade	Severely limiting	1.078 (1.060 to 1.097)	<0.001
	Moderately limiting	1.036 (1.016 to 1.056)	<0.001
	High intensity	1.022 (1.013 to 1.031)	<0.001
	Low intensity	0.995 (0.968 to 1.023)	0.746
	No chronic pain	Ref
Income quintile	Highest quintile	1.017 (1.004 to 1.030)	0.008
	4th	1.018 (1.006 to 1.030)	0.004
	3rd	1.018 (1.006 to 1.030)	0.003
	2nd	1.016 (1.004 to 1.028)	0.007
	Lowest quintile	Ref
Highest qualification	No qualification	1.012 (1.000 to 1.024)	0.059
	Foreign/other	1.005 (0.972 to 1.039)	0.761
	NVQ level 1 or equivalent	1.002 (0.984 to 1.021)	0.809
	NVQ level 2 or equivalent	1.004 (0.994 to 1.015)	0.400
	NVQ level 3 or equivalent	1.011 (1.000 to 1.022)	0.050
	NVQ level 4 or equivalent	1.005 (0.992 to 1.017)	0.461
	NVQ level 5 orequivalent	Ref
General health	Very bad	1.137 (1.102 to 1. 174)	<0.001
	Bad	1.057 (1.035 to 1.080)	<0.001
	Fair	1.022 (1.010 to 1.034)	<0.001
	Good	1.000 (0.992 to 1.008)	0.995
	Very good	Ref
Anxiety	Extreme	1.015 (0.991 to 1.039)	0.227
	Moderate	1.008 (1.000 to 1.017)	0.052
	Not anxious	Ref