Statistical Process Control (SPC) to drive improvement in length of stay after colorectal surgery

Am J Surg. 2020 Jun;219(6):1006-1011. doi: 10.1016/j.amjsurg.2019.08.029. Epub 2019 Sep 10.

Abstract

Background: Novel quality improvement(QI) methods are needed to optimize healthcare costs and value. Our goal was to determine if Statistical Process Control(SPC), an industrial QI tool, could transform length of stay(LOS) into a process measure, identify outliers, and their impact on surgical outcomes.

Methods: SPC was performed on an institutional colorectal resection database 1/1/13-5/1/2018 to identify outliers and compare outcome variables across outliers and non-outliers. Control charts analyzed the process performance of LOS over time. Control limits were set at ± 1 standard deviation(SD) from the mean. Measures were stable within these limits.

Results: LOS was stable, with consistent annual rates and variation of outliers. Outliers had identifiable causes of variation that were significantly different from non-outliers(p < 0.05). The variation resulted in more complications, readmissions, and reoperations in outliers(p < 0.05).

Conclusions: SPC can be applied to LOS, a stable process measure with decreasing variability over time, and easy outlier identification. Identifying outliers can facilitate targeted quality improvement.

Keywords: Colorectal surgery; Healthcare outcomes; Length of stay; Quality improvement; Statistical process control (SPC).

MeSH terms

  • Aged
  • Colonic Diseases / surgery*
  • Female
  • Humans
  • Length of Stay / statistics & numerical data*
  • Male
  • Middle Aged
  • Process Assessment, Health Care / statistics & numerical data*
  • Quality Improvement / statistics & numerical data*
  • Rectal Diseases / surgery*
  • Retrospective Studies
  • Treatment Outcome