Imaging for low back pain: is clinical use consistent with guidelines? A systematic review and meta-analysis.

BACKGROUND CONTEXT: The problem of imaging patients with low back pain (LBP) when it is not indicated is well recognized. The converse is also possible, although rarely considered. The extent of these two problems is presently unclear. PURPOSE: This study aimed to estimate how commonly overuse, and also underuse, of imaging occurs in the management of LBP, and how appropriate use of imaging is assessed. DESIGN: This is a systematic review and meta-analysis. PATIENT SAMPLE: The sample comprised patients with LBP presenting to primary care. OUTCOME MEASURES: Proportions of inappropriate referral, and inappropriate non-referral, for diagnostic imaging for LBP were the outcome measures. METHODS: MEDLINE, EMBASE, and CINAHL were searched from January 1, 1995 to December 17, 2017. Two authors independently assessed study quality and extracted data. Meta-analyses were performed where appropriate, and strength of evidence was assessed using the Grading of Recommendations, Assessment, Development and Evaluation system. RESULTS: Thirty-three studies were included. In patients referred for lumbar imaging, 34.8% (95% confidence interval [CI]: 27.1, 43.3) were judged inappropriate by the absence of red flags for serious pathology and 31.6% (95% CI: 28.3, 35.1) were judged inappropriate by the criteria of no clinical suspicion of pathology. In patients presenting for care, imaging was inappropriately performed in 27.7% of cases (95% CI: 21.3, 35.1) when judged by duration of episode, 9.0% of cases (95% CI: 7.4, 11.0) when judged by absence of red flags, and 7.0% (95% CI: 1.8, 23.3) when judged by no clinical suspicion of pathology. In patients presenting for care, imaging was not performed where appropriately indicated in 65.6% (95% CI: 51.8, 77.2) of patients who presented with red flags, and 60.8% (95% CI: 42.0, 76.8) with clinical suspicion of serious pathology. CONCLUSIONS: Inappropriate imaging is common in LBP management, including both overuse in those where imaging is not indicated and underuse of imaging when it is indicated. Appreciating that both underuse and overuse can occur is fundamental to efforts to improve imaging practice to align with current guidelines and best evidence.