Variation among Primary Care Physicians in the Use of Imaging for Older Patients with Acute Low Back Pain

J Gen Intern Med. 2016 Feb;31(2):156-163. doi: 10.1007/s11606-015-3475-3. Epub 2015 Jul 28.


Background: Diagnostic imaging is not recommended in the evaluation and management of non-specific acute low back pain.

Objective: To estimate the variation among primary care providers (PCPs) in the use of diagnostic imaging for older patients with non-specific acute low back pain.

Design and participants: Retrospective cohort study using 100 % Texas Medicare claims data. We identified 145,320 patients aged 66 years and older with non-specific acute low back pain during the period January 1, 2007, through November 30, 2011, cared for by 3297 PCPs.

Main measures: We tracked whether each patient received lumbar imaging (radiography, computed tomography [CT], or magnetic resonance imaging [MRI]) within 4 weeks of the initial visit. Multilevel logistic regression models were used to estimate physician-level variation in imaging use.

Key results: Among patients, 27.2 % received radiography and 11.1 % received CT or MRI within 4 weeks of the initial visit for low back pain. PCPs varied substantially in the use of imaging. The average rate of radiography within 4 weeks was 53.9 % for PCPs in the highest decile, compared to 6.1 % for PCPs in the lowest decile. The average rates of CT/MRI within 4 weeks were 18.5 % vs. 3.2 % for PCPs in the highest and lowest deciles, respectively. The specific physician seen by a patient accounted for 25 % of the variability in whether imaging was performed, while only 0.44 % of the variance was due to measured patient characteristics and 1.4 % to known physician characteristics. Use of imaging by individual physicians was stable over time.

Conclusions: PCPs vary substantially in the use of imaging for non-specific acute low back pain. Provider-level measures can be employed to provide feedback to physicians in an effort to modify imaging use.

Keywords: back pain; care management; practice variation; primary care; quality assessment.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Acute Pain / diagnosis*
  • Aged
  • Aged, 80 and over
  • Diagnostic Imaging / statistics & numerical data*
  • Female
  • Health Services Misuse / statistics & numerical data
  • Humans
  • Low Back Pain / diagnosis*
  • Lumbar Vertebrae / diagnostic imaging
  • Lumbar Vertebrae / pathology
  • Magnetic Resonance Imaging / statistics & numerical data
  • Male
  • Medicare / statistics & numerical data
  • Physicians, Primary Care / statistics & numerical data*
  • Practice Guidelines as Topic
  • Professional Practice / statistics & numerical data*
  • Retrospective Studies
  • Texas
  • Tomography, X-Ray Computed / statistics & numerical data
  • United States