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The Cascade of Medical Services and Associated Longitudinal Costs Due to Nonadherent Magnetic Resonance Imaging for Low Back Pain

Webster, Barbara S. BSPT, PA*,†; Choi, YoonSun MA*; Bauer, Ann Z. MPH; Cifuentes, Manuel MD, MPH, ScD*,‡; Pransky, Glenn MD, MOccH*

doi: 10.1097/BRS.0000000000000408
Health Services Research

Study Design. Retrospective cohort study.

Objective. To compare type, timing, and longitudinal medical costs incurred after adherent versus nonadherent magnetic resonance imaging (MRI) for work-related low back pain.

Summary of Background Data. Guidelines advise against MRI for acute uncomplicated low back pain, but is an option for persistent radicular pain after a trial of conservative care. Yet, MRI has become frequent and often nonadherent. Few studies have documented the nature and impact of medical services (including type and timing) initiated by nonadherent MRI.

Methods. A longitudinal, workers' compensation administrative data source was accessed to select low back pain claims filed between January 1, 2006 and December 31, 2006. Cases were grouped by MRI timing (early, timely, no MRI) and subgrouped by severity (“less severe,” “more severe”) (final cohort = 3022). Health care utilization for each subgroup was evaluated at 3, 6, 9, and 12 months post-MRI. Multivariate logistic regression models examined risk of receiving subsequent diagnostic studies and/or treatments, adjusting for pain indicators and demographic covariates.

Results. The adjusted relative risks for MRI group cases to receive electromyography, nerve conduction testing, advanced imaging, injections, and surgery within 6 months post-MRI risks in the range from 6.5 (95% CI: 2.20–19.09) to 54.9 (95% CI: 22.12–136.21) times the rate for the referent group (no MRI less severe). The timely and early MRI less severe subgroups had similar adjusted relative risks to receive most services. The early MRI more severe subgroup cases had generally higher adjusted relative risks than timely MRI more severe subgroup cases. Medical costs for both early MRI subgroups were highest and increased the most over time.

Conclusion. The impact of nonadherent MRI includes a wide variety of expensive and potentially unnecessary services, and occurs relatively soon post-MRI. Study results provide evidence to promote provider and patient conversations to help patients choose care that is based on evidence, free from harm, less costly, and truly necessary.

Level of Evidence: N/A

Magnetic resonance imaging (MRI) without clear indications led to a cascade of subsequent diagnostic and invasive services, which occurred within 6 months after imaging. Early MRI was significantly associated with a large and sustained escalation in medical costs, even after grouping by severity and controlling for pain and demographic covariates.

*Center for Disability Research, Liberty Mutual Research Institute for Safety, Hopkinton, MA

Major Accounts Division, Helmsman Management Services LLC, Liberty Mutual Insurance, Boston, MA; and

University of Massachusetts-Lowell, Lowell, MA.

Address correspondence and reprint requests to Glenn Pransky, MD, MOccH, Liberty Mutual Research Institute for Safety, 71 Frankland Rd, Hopkinton, MA 01748; E-mail:

Acknowledgment date: March 7, 2014. Revision date: April 16, 2014. Acceptance date: April 22, 2014.

The manuscript submitted does not contain information about medical device(s)/drug(s).

One of the authors (A.Z.B.) received student internship funding from the University of Massachusetts-Lowell for participation in review activities such as data monitoring boards, statistical analysis, end point committees, and the like and writing or reviewing the manuscript.

Relevant financial activities outside the submitted work: employment.

This is an open-access article distributed under the terms of the Creative Commons Attribution-NonCommercial-NoDerivitives 3.0 License, where it is permissible to download and share the work provided it is properly cited. The work cannot be changed in any way or used commercially.

© 2014 by Lippincott Williams & Wilkins