title: Cumulative sum: a proficiency metric for basic endoscopic training.
abstract: BACKGROUND
  As work hour restrictions increasingly limit some operative experiences, personalized evaluative methods are needed. We prospectively assessed the value of cumulative sum (Cusum) to measure proficiency with percutaneous endoscopic gastrostomy (PEG) among surgical trainees.
  
  
  METHODS
  Nine postgraduate year 1 surgery residents each underwent a 1-month rotation dedicated to endoscopy. Procedure durations for all PEG insertions were recorded prospectively. Criteria for task failure included need for attending takeover or procedure duration >10 min. Cusum parameters were defined a priori, with acceptable and unacceptable failure rates of 5% and 15%, respectively. Concurrently, expert endoscopists blinded to Cusum results evaluated trainee proficiency weekly using a multicategory, five-point Likert-scale survey.
  
  
  RESULTS
  Nine surgical residents performed an average of 21 PEGs each. Expert evaluations and Cusum analyses identified eight and seven participants who attained proficiency after a median of 11.5 and 12 cases, respectively. For four of the residents who achieved proficiency by Cusum criteria, eventual relapses to inadequate performance were identified. These relapses were not detected by expert evaluation. Six participants who attained proficiency by both metrics performed a combined 32 superfluous cases, which could have been redistributed to poor-performing trainees.
  
  
  CONCLUSIONS
  Although lacking the granular insight of expert evaluations, Cusum analysis is more sensitive to relapses of subproficient performance. Adding Cusum analysis to expert evaluations can provide longitudinal, formative feedback and promote efficient redistribution of operative experiences.
authors: Department of Surgery, University of Virginia, Charlottesville, Virginia.
authors: Yinin
authors: Y
authors: Hu
authors: University of Virginia School of Medicine, Charlottesville, Virginia.
authors: Joshua S
authors: JS
authors: Jolissaint
authors: Department of Surgery, University of Virginia, Charlottesville, Virginia.
authors: Adriana
authors: A
authors: Ramirez
authors: University of Virginia School of Medicine, Charlottesville, Virginia.
authors: Ryan
authors: R
authors: Gordon
authors: Department of Surgery, University of Virginia, Charlottesville, Virginia.
authors: Zequan
authors: Z
authors: Yang
authors: Department of Surgery, University of Virginia, Charlottesville, Virginia. Electronic address: rws2k@virginia.edu.
authors: Robert G
authors: RG
authors: Sawyer
mesh_terms: D002983:Clinical Competence; D003162:Competency-Based Education / Q000379:methods*; D004521:Educational Measurement / Q000379:methods*; D004724:Endoscopy / Q000193:education*; D005774:Gastrostomy / Q000193:education*; D006801:Humans; D007396:Internship and Residency / Q000379:methods*; D007858:Learning; D017145:Models, Educational
keywords: Cumulative sum; Evaluation; Learning curve; Percutaneous gastrostomy; Resident training; Upper endoscopy