Systematic Review of the Application of Lean and Six Sigma Quality Improvement Methodologies in Radiology

J Am Coll Radiol. 2016 Sep;13(9):1088-1095.e7. doi: 10.1016/j.jacr.2016.02.033. Epub 2016 May 19.


Purpose: Preventable yet clinically significant rates of medical error remain systemic, while health care spending is at a historic high. Industry-based quality improvement (QI) methodologies show potential for utility in health care and radiology because they use an empirical approach to reduce variability and improve workflow. The aim of this review was to systematically assess the literature with regard to the use and efficacy of Lean and Six Sigma (the most popular of the industrial QI methodologies) within radiology.

Methods: MEDLINE, the Allied & Complementary Medicine Database, Embase Classic + Embase, Health and Psychosocial Instruments, and the Ovid HealthStar database, alongside the Cochrane Library databases, were searched on June 2015. Empirical studies in peer-reviewed journals were included if they assessed the use of Lean, Six Sigma, or Lean Six Sigma with regard to their ability to improve a variety of quality metrics in a radiology-centered clinical setting.

Results: Of the 278 articles returned, 23 studies were suitable for inclusion. Of these, 10 assessed Six Sigma, 7 assessed Lean, and 6 assessed Lean Six Sigma. The diverse range of measured outcomes can be organized into 7 common aims: cost savings, reducing appointment wait time, reducing in-department wait time, increasing patient volume, reducing cycle time, reducing defects, and increasing staff and patient safety and satisfaction. All of the included studies demonstrated improvements across a variety of outcomes. However, there were high rates of systematic bias and imprecision as per the Grading of Recommendations Assessment, Development and Evaluation guidelines.

Conclusions: Lean and Six Sigma QI methodologies have the potential to reduce error and costs and improve quality within radiology. However, there is a pressing need to conduct high-quality studies in order to realize the true potential of these QI methodologies in health care and radiology. Recommendations on how to improve the quality of the literature are proposed.

Keywords: Lean; Quality improvement; Six Sigma; diagnostic imaging; radiology.

Publication types

  • Meta-Analysis
  • Review
  • Systematic Review

MeSH terms

  • Cost Savings / standards
  • Cost Savings / statistics & numerical data*
  • Delivery of Health Care / economics
  • Delivery of Health Care / statistics & numerical data
  • Diagnostic Imaging / economics*
  • Diagnostic Imaging / standards
  • Diagnostic Imaging / statistics & numerical data
  • Efficiency, Organizational
  • Internationality
  • Medical Errors / economics*
  • Medical Errors / prevention & control
  • Medical Errors / statistics & numerical data
  • Organizational Objectives / economics
  • Patient Safety / economics
  • Patient Safety / statistics & numerical data
  • Practice Guidelines as Topic
  • Quality Improvement / economics*
  • Quality Improvement / statistics & numerical data
  • Radiology / economics*
  • Radiology / standards*
  • Reproducibility of Results
  • Sensitivity and Specificity
  • Total Quality Management / standards*
  • Total Quality Management / statistics & numerical data
  • United States
  • Waiting Lists
  • Workflow