title: Improving the identification of postoperative wound dehiscence missed by the Patient Safety Indicator algorithm.
abstract: BACKGROUND
  The Patient Safety Indicator (PSI) Postoperative Wound Dehiscence (PWD) is an administrative data-based algorithm that flags cases using International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) code 54.61 (abdominal wall disruption reclosure). We examined how often PWD missed events and explored ways to improve event identification.
  
  
  METHODS
  We selected 125 high-risk unflagged cases based on predicted probability and the presence of clinically relevant codes. We determined the false-negative proportion and associated reasons through chart review and calculated likelihood ratios of associated codes.
  
  
  RESULTS
  Thirty-two percent of cases were false negatives, 60% of which lacked any abdominal wall repair codes. All individual codes had low likelihood ratios; the combination of diagnosis code 998.3x (operative wound disruption) and particular abdominal wall repair procedure codes occurred exclusively in false-negative cases (representing 24% of false-negative cases).
  
  
  CONCLUSIONS
  Among high-risk cases, the PWD algorithm frequently missed events. Coder training to clarify assignment of abdominal wall repair codes, plus adding specific code combinations to the algorithm, would improve event identification.
authors: Center for Health Quality, Outcomes and Economic Research, Bedford VA Medical Center, Bedford, MA 01730, USA. amb@bu.edu
authors: Ann M
authors: AM
authors: Borzecki
authors: Marisa
authors: M
authors: Cevasco
authors: Hillary
authors: H
authors: Mull
authors: Marlena
authors: M
authors: Shin
authors: Kamal
authors: K
authors: Itani
authors: Amy K
authors: AK
authors: Rosen
mesh_terms: D034861:Abdominal Wall / Q000601:surgery; D000465:Algorithms; D059019:Clinical Coding; D003430:Cross-Sectional Studies; D005188:False Negative Reactions; D006801:Humans; D038801:International Classification of Diseases; D016013:Likelihood Functions; D061214:Patient Safety; D019984:Quality Indicators, Health Care; D012189:Retrospective Studies; D013529:Surgical Wound Dehiscence / Q000145:classification* / Q000453:epidemiology