Geographic Variation in Early MRI for Acute Work-Related Low Back Pain and Associated Factors.
METHODS
Retrospective cohort study using medical claims data.


OBJECTIVE
To document the extent of geographic variation in utilization of magnetic resonance imaging (MRI) for working-age patients early in the course of acute, disabling low back pain (LBP); to identify potential factors associated with the most extreme variations.


BACKGROUND
Although guidelines discourage MRI in acute uncomplicated LBP, this practice is highly prevalent. Geographic variation in radiologic testing is common, and may indicate problems with access or quality of care, yet this has not been studied in working-age patients with LBP (a frequent cause for acute care visits).


METHODS
All cases of acute, disabling LBP with onset between 1/1/2002 and 12/31/2007 were selected from a large workers' compensation data source. Detailed information from medical bills was used to identify persons who received early MRI (within 30 days of onset), classify cases by LBP severity, and exclude those with concurrent injuries or diseases, and/or prior LBP disability. Individual predictors included age, gender, job tenure, and industry. State-level predictors included economic, physician supply and practice variables, workers compensation system features, and MRI testing location. Generalized linear mixed models were constructed to evaluate within- and between-state variability, selecting the six highest and six lowest MRI utilization states.


RESULTS
State rates of early MRI scanning varied from 6.0% to 58.4%. In the 12 selected most extreme states, non-hospital MRI sites and lower state median income were associated with higher rates of early MRIs, explaining 84% of between-state variation, and 12.5% of all observed variability. Inter-state differences in MRI rates were greatest for lower-severity cases. Higher severity diagnoses were more common in high utilization states.


CONCLUSIONS
Between-state inappropriate early MRI variability is largely explained by rate of non-hospital MRI sites and state median income. Potential solutions include efforts to address inappropriate referral patterns based on private MRI facility ownership, and to improve quality of communication with low-income patients.


METHODS
4.
*Center for Disability Research, Liberty Mutual Research Institute for Safety, Hopkinton, MA †Department of Work Environment, University of Massachusetts Lowell, Lowell, MA ‡Center for Health Policy and Health Services Research, University of Massachusetts Medical School, Shrewsbury, MA §Helmsman Management Services LLC, Liberty Mutual Insurance, Boston, MA.
Glenn
G
Pransky
Gloria
G
Foley
Manuel
M
Cifuentes
Barbara S
BS
Webster
D000208:Acute Disease; D000328:Adult; D005260:Female; D006801:Humans; D017116:Low Back Pain / Q000175:diagnosis* / Q000453:epidemiology; D008279:Magnetic Resonance Imaging / Q000706:statistics & numerical data*; D008297:Male; D009784:Occupational Diseases / Q000175:diagnosis* / Q000453:epidemiology; D012189:Retrospective Studies; D014481:United States / Q000453:epidemiology