Predictors of long-term pain and disability in patients with low back pain investigated by magnetic resonance imaging: A longitudinal study

Table 3 Prevalence of low back pain at follow-up according to MRI findings, psychological characteristics at baseline and treatment received

	LBP in past 4 weeks				LBP on > 14 days in past 4 weeks				Disabling LBP in past 4 weeks^a
	n	%	PR^b	(95% CI)	n	%	PR^b	(95% CI)	n	%	PR^b	(95% CI)
Number of MRI abnormalities
0	26	81	1	-	13	41	1	-	8	25	1	-
1	22	69	0.8	(0.6-1.1)	10	31	0.6	(0.3-1.3)	9	28	0.9	(0.4-2.0)
2	45	69	0.9	(0.7-1.1)	19	30	0.7	(0.4-1.2)	17	26	0.9	(0.4-2.0)
3	44	72	0.9	(0.7-1.1)	25	43	0.9	(0.6-1.6)	16	26	0.9	(0.4-1.9)
4	32	74	1.0	(0.8-1.2)	18	43	1.0	(0.6-1.8)	20	47	1.8	(0.9-3.6)
Mental Health
Good	48	68	1	-	21	30	1	-	14	20	1	-
Intermediate	55	75	1.2	(0.9-1.4)	27	39	1.4	(0.9-2.2)	23	32	1.6	(0.9-2.9)
Poor	66	74	1.1	(0.9-1.3)	37	42	1.3	(0.8-2.1)	33	37	1.7	(0.9-3.0)
Number of distressing somatic symptoms
0	88	68	1	-	41	33	1	-	31	24	1	-
1	36	72	1.1	(0.9-1.3)	17	36	1.0	(0.6-1.6)	17	34	1.4	(0.8-2.3)
≥2	45	83	1.2	(1.0-1.5)	27	50	1.4	(0.9-2.1)	22	41	1.6	(1.0-2.5)
Treatment
None^c	77	69	1	-	35	32	1	-	32	29	1	-
Surgery^d	23	56	0.8	(0.6-1.1)	12	30	0.9	(0.5-1.6)	10	24	0.7	(0.4-1.4)
Injections or physical therapy but not surgery^e	69	85	1.2	(1.1-1.4)	38	49	1.6	(1.1-2.3)	28	35	1.3	(0.8-1.9)

^aRoland Morris score > 11
^bPrevalence ratios adjusted for the other risk factors in the table, and also for sex and age (20-39, 40-49 and 50-64 years). For each regression model, analysis was restricted to patients with complete information on all relevant variables (233 for LBP in past 4 weeks, 227 for LBP on > 14 days in past 4 weeks, and 233 for disabling LBP in past 4 weeks).
^cNo back surgery after MRI investigation and no injections or physical therapy after baseline questionnaire
^dBack surgery after MRI investigation
^eInjections or physical therapy after baseline questionnaire, but no back surgery after MRI investigation

ISSN: 1471-2474