Improving Papanicolaou test quality and reducing medical errors by using Toyota production system methods

Am J Obstet Gynecol. 2006 Jan;194(1):57-64. doi: 10.1016/j.ajog.2005.06.069.


Objective: The objective of the study was to determine whether the Toyota production system process improves Papanicolaou test quality and patient safety.

Study design: An 8-month nonconcurrent cohort study that included 464 case and 639 control women who had a Papanicolaou test was performed. Office workflow was redesigned using Toyota production system methods by introducing a 1-by-1 continuous flow process. We measured the frequency of Papanicolaou tests without a transformation zone component, follow-up and Bethesda System diagnostic frequency of atypical squamous cells of undetermined significance, and diagnostic error frequency.

Results: After the intervention, the percentage of Papanicolaou tests lacking a transformation zone component decreased from 9.9% to 4.7% (P = .001). The percentage of Papanicolaou tests with a diagnosis of atypical squamous cells of undetermined significance decreased from 7.8% to 3.9% (P = .007). The frequency of error per correlating cytologic-histologic specimen pair decreased from 9.52% to 7.84%.

Conclusions: The introduction of the Toyota production system process resulted in improved Papanicolaou test quality.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Case-Control Studies
  • Cohort Studies
  • Diagnostic Errors / prevention & control*
  • Diagnostic Errors / statistics & numerical data
  • Efficiency, Organizational
  • Female
  • Humans
  • Papanicolaou Test*
  • Process Assessment, Health Care
  • Quality Assurance, Health Care*
  • Time Factors
  • Uterine Cervical Neoplasms / diagnosis*
  • Vaginal Smears / standards*