title: Empirically derived maximal acceptable wait time for surgery to treat adolescent idiopathic scoliosis.
abstract: BACKGROUND
  Prioritizing patients using empirically derived access targets can help to ensure high-quality care. Adolescent scoliosis can worsen while patients wait for treatment, increasing the risk of adverse events. Our objective was to determine an empirically derived access target for scoliosis surgery and to compare this with consensus-based targets.
  
  
  METHODS
  Two-hundred sixteen sequential patients receiving surgery for adolescent idiopathic scoliosis were included in the study. The main outcome was need for additional surgery. Logistic regression modeling was used to evaluate the relation between surgical wait times and adverse events and χ2 analysis was used as the primary analysis for the main outcome.
  
  
  RESULTS
  Of the 88 patients who waited longer than six months for surgery, 13 (14.8%) needed additional surgery due to progression of curvature versus 1.6% (2 of 128 patients) who waited less than six months for surgery (χ2 analysis, p=0.0001). Patients who waited longer than six months for surgery had greater progression of curvature, longer surgeries and longer stays in hospital. These patients also had less surgical correction than patients who waited less than six months for surgery (Wilcoxon-Mann-Whitney test, p=0.011). All patients requiring additional surgeries waited longer than three months for their initial surgery. A receiver-operator characteristic curve also suggested a three-month wait as an access target. The adjusted odds ratio for an adverse event for each additional 90 days of waiting from time of consent was 1.81 (95% confidence interval 1.34-2.44). The adjusted odds ratio increased with skeletal immaturity and with the size of the spinal curvature at the time of consent.
  
  
  CONCLUSIONS
  A prolonged wait for surgery increased the risk of additional surgical procedures and other adverse events. An empirically derived access target of three months for surgery to treat adolescent idiopathic scoliosis could potentially eliminate the need for additional surgery by reducing progression of curvature. This is a shorter access target than the six months determined by expert consensus.
authors.affiliation: St. Michael's Hospital, University of Toronto Spine Program, Department of Surgery, University of Toronto, Toronto, Ontario. ahnh@smh.ca
authors.forename: Henry
authors.initials: H
authors.lastname: Ahn
authors.forename: Hans
authors.initials: H
authors.lastname: Kreder
authors.forename: Nizar
authors.initials: N
authors.lastname: Mahomed
authors.forename: Dorcas
authors.initials: D
authors.lastname: Beaton
authors.forename: James G
authors.initials: JG
authors.lastname: Wright
mesh_terms: D000293:Adolescent; D002648:Child; D005260:Female; D006801:Humans; D008297:Male; D009864:Ontario; D012372:ROC Curve; D012086:Reoperation; D012600:Scoliosis / Q000601:surgery*; D016896:Treatment Outcome; D014850:Waiting Lists