title: Monitoring trends in waiting periods in Canada for elective surgery: validation of a method using administrative data.
abstract: BACKGROUND
  Provincial governments require timely, economical methods to monitor surgical waiting periods. Although use of prospective procedure-specific registers would be the ideal method, a less elaborate system has been proposed that is based on physician billing data. This study assessed the validity of using the date of the last service billed prior to surgery as a proxy for the beginning of the post-referral, pre-surgical waiting period.
  
  
  METHODS
  We examined charts for 31,824 elective surgical encounters between 1992 and 1996 at an Ontario teaching hospital. The date of the last service before surgery (the last billing date) was compared with the date of the consultant's letter indicating a decision to book surgery (i.e., to begin waiting).
  
  
  RESULTS
  Several surgical specialties (but excluding cardiac, orthopedic and gynecologic) had a close correlation between the dates of the last pre-surgery visit and those of the actual decision to place the patient on the waiting list. Similar results were found for 12 of 15 individually studied procedures, including some orthopedic and gynecological procedures.
  
  
  CONCLUSIONS
  Used judiciously, billing data is a timely, inexpensive and generally accurate method by which provincial governments could monitor trends in waiting times for appropriately selected surgical procedures.
authors.affiliation: Centre for Health Services and Policy Research, Queen's University, Kingston, Ont. seds@post.queensu.ca
authors.forename: Samuel E D
authors.initials: SE
authors.lastname: Shortt
authors.forename: Ralph A
authors.initials: RA
authors.lastname: Shaw
authors.forename: David
authors.initials: D
authors.lastname: Elliott
authors.forename: William J
authors.initials: WJ
authors.lastname: Mackillop
mesh_terms: D000704:Analysis of Variance; D002170:Canada; D003558:Cystoscopy / Q000706:statistics & numerical data; D004107:Dilatation and Curettage / Q000706:statistics & numerical data; D017558:Elective Surgical Procedures / Q000706:statistics & numerical data*; D005260:Female; D006801:Humans; D007044:Hysterectomy / Q000706:statistics & numerical data; D007344:Insurance Claim Reporting / Q000706:statistics & numerical data*; D010535:Laparoscopy / Q000706:statistics & numerical data; D008297:Male; D008485:Medical Audit; D011468:Prostatectomy / Q000706:statistics & numerical data; D014621:Vagina / Q000601:surgery; D014850:Waiting Lists