Purpose: Information on the prognostic value of MRI findings in low back pain patients in primary care is lacking. The objective of this study is to investigate the added prognostic value of baseline MRI findings over known prognostic factors for recovery at 12-month follow-up in patients with low back pain referred to MRI by their general practitioner.
Methods: Patients referred by their general practitioner for MRI of the lumbar spine were recruited at the MRI Center. The questionnaires at baseline and at 3 and 12-months follow-up included potential clinical predictors from history taking and the outcome recovery. The MRI radiology reports were scored. Analysis was performed in 3 steps: derivation of a predictive model including characteristics of the patients and back pain only (history taking), including reported MRI findings only, and the addition of reported MRI findings to the characteristics of the patients and back pain.
Results: At 12-months follow-up 53% of the patients reported recovery (n = 683). Lower age, better attitude/beliefs regarding back pain, acute back pain, presence of neurological symptoms of the leg(s), and presence of non-continuous back pain were significantly associated with recovery at 12-months follow-up: area under the curve (AUC) 0.77. Addition of the MRI findings resulted in an AUC of 0.78.
Conclusions: At 12-months follow-up, only 53% of these patients with low back pain referred for MRI in general practice reported recovery. Five clinic baseline characteristics were associated with recovery at 12-months follow-up; adding the MRI findings did not result in a stronger prediction of recovery.
Keywords: Area under curve; Logistic models; Low back pain; Low back pain/diagnosis; Magnetic resonance imaging; Outcome; Predictive value of tests; Primary health care.