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Comment & Response
May 2018

Rigor in Quality Improvement Studies and the Role of Time-Series Methodologies

Author Affiliations
  • 1Department of Medicine, Centre for Quality Improvement and Patient Safety (C-QuIPS), University of Toronto, Toronto, Ontario, Canada
  • 2Department of Medicine, University of Toronto, Toronto, Ontario, Canada
JAMA Intern Med. 2018;178(5):724-725. doi:10.1001/jamainternmed.2018.0863

To the Editor In response to the Editorial by Grady and colleagues about quality improvement for quality improvement studies1 that was published in a recent issue of JAMA Internal Medicine, we disagree that rigor always requires concurrent controls and randomization. Time series with multiple data points provide comparable evaluative rigor to controlled, nonrandomized trials. When an intervention needs refinement, as is often the case in quality improvement, they often represent a more efficient evaluative strategy. The SQUIRE guidelines,2 which Grady and colleagues1 recommend to encourage improved reporting, explicitly list analyses that include the effects of time as a variable as appropriate.

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