A systematic review of diagnostic imaging use for low back pain in the United States

Background contextVarious studies have reported on the increasing use and costs of diagnostic imaging for low back pain (LBP) in the United States. However, it is unclear whether the methods used in these studies allowed for meaningful comparisons or whether the reported use data can be used to develop evidence-based use benchmarks.PurposeThe primary purpose of this study was to review previous estimates of the use of diagnostic imaging for LBP in the United States.Study design/settingThe study design is a systematic review of published literature.MethodsA search through May 2012 was conducted using keywords and free text terms related to health services and LBP in Medline and Health Policy Reference; results were screened for relevance independently, and full-text studies were assessed for eligibility. Only studies published in English since the year 2000 reporting on use of diagnostic imaging for LBP using claims data from the United States were included. Reporting quality was assessed using a modified Downs and Black tool for observational studies.ResultsThe search strategy yielded 1,102 citations, seven of which met the criteria for eligibility. Studies reported use from commercial health plans (N=4) and Medicare (N=3), with sample sizes ranging from 13,760 to 740,467 members with LBP from specific states or across the United States. The number of diagnostic codes used to identify nonspecific LBP ranged from 2 to 66; other heterogeneity was noted in the methods used across these studies. In commercial health plans, use of radiography occurred in 12.0% to 32.2% of patients with LBP, magnetic resonance imaging (MRI) was used in 16.0% to 21.0%, computed tomography (CT) was used in 1.4% to 3.0%, and MRI and/or CT was used in 10.9% to 16.1%. Findings in Medicare populations were 22.9% to 48.2% for radiography, 11.6% for MRI, and 10.4% to 16.3% for MRI and/or CT.ConclusionsThe reported use of diagnostic imaging for LBP varied across the studies reviewed; differences in methodology made meaningful comparisons difficult. Standardizing methods for performing and reporting analyses of claims data related to use could facilitate efforts by third-party payers, health care providers, and researchers to identify and address the perceived overuse of diagnostic imaging for LBP.