title: Are anesthesia start and end times randomly distributed? The influence of electronic records.
abstract: OBJECTIVE
  To perform a frequency analysis of start minute digits (SMD) and end minute digits (EMD) taken from the electronic, computer-assisted, and manual anesthesia billing-record systems.
  
  
  METHODS
  Retrospective cross-sectional review.
  
  
  METHODS
  University medical center.
  
  
  METHODS
  This cross-sectional review was conducted on billing records from a single healthcare institution over a 15-month period. A total of 30,738 cases were analyzed. For each record, the start time and end time were recorded. Distributions of SMD and EMD were tested against the null hypothesis of a frequency distribution equivalently spread between zero and nine.
  
  
  RESULTS
  SMD and EMD aggregate distributions each differed from equivalency (P < 0.0001). When stratified by type of anesthetic record, no differences were found between the recorded and expected equivalent distribution patterns for electronic anesthesia records for start minute (P < 0.98) or end minute (P < 0.55). Manual and computer-assisted records maintained nonequivalent distribution patterns for SMD and EMD (P < 0.0001 for each comparison). Comparison of cumulative distributions between SMD and EMD distributions suggested a significant difference between the two patterns (P < 0.0001).
  
  
  CONCLUSIONS
  An electronic anesthesia record system, with automated time capture of events verified by the user, produces a more unified distribution of billing times than do more traditional methods of entering billing times.
authors.affiliation: Department of Anesthesiology, University of Florida College of Medicine, Gainesville, FL 32610-0254, USA.
authors.forename: Litisha G
authors.initials: LG
authors.lastname: Deal
authors.affiliation: University of Florida College of Medicine, Gainesville, FL 32610, USA. Electronic address: mnyland@anest.ufl.edu.
authors.forename: Michael E
authors.initials: ME
authors.lastname: Nyland
authors.affiliation: Department of Anesthesiology, University of Florida College of Medicine, Gainesville, FL 32610-0254, USA.
authors.forename: Nikolaus
authors.initials: N
authors.lastname: Gravenstein
authors.affiliation: Department of Anesthesiology, University of Florida College of Medicine, Gainesville, FL 32610-0254, USA. Electronic address: ptighe@anest.ufl.edu.
authors.forename: Patrick
authors.initials: P
authors.lastname: Tighe
mesh_terms: D000046:Academic Medical Centers; D000758:Anesthesia / Q000191:economics / Q000379:methods*; D001331:Automation; D003430:Cross-Sectional Studies; D057286:Electronic Health Records / Q000706:statistics & numerical data*; D005249:Fees and Charges; D006801:Humans; D016347:Medical Records Systems, Computerized; D012051:Reimbursement Mechanisms; D012189:Retrospective Studies; D013997:Time Factors
keywords: Anesthesia billing; Anesthesia procedure start times; Electronic anesthesia record; End minute digit; Procedure timekeeping; Start minute digit