title: Rates of minor adverse events and health resource utilization postcolonoscopy.
abstract: BACKGROUND
  Little is known about minor adverse events (MAEs) following outpatient colonoscopies and associated health care resource utilization.
  
  
  OBJECTIVE
  To estimate the rates of incident MAE at two, 14 and 30 days postcolonoscopy, and associated health care resource utilization. A secondary aim was to identify factors associated with cumulative 30-day MAE incidence.
  
  
  METHODS
  A longitudinal cohort study was conducted among individuals undergoing an outpatient colonoscopy at the Montreal General Hospital (Montreal, Quebec). Before colonoscopy, consecutive individuals were enrolled and interviewed to obtain data regarding age, sex, comorbidities, use of antiplatelets/anticoagulants and previous symptoms. Endoscopy reports were reviewed for intracolonoscopy procedures (biopsy, polypectomy). Telephone or Internet follow-up was used to obtain data regarding MAEs (abdominal pain, bloating, diarrhea, constipation, nausea, vomiting, blood in the stools, rectal or anal pain, headaches, other) and health resource use (visits to emergency department, primary care doctor, gastroenterologist; consults with nurse, pharmacist or telephone hotline). Rates of incident MAEs and health resources utilization were estimated using Bayesian hierarchical modelling to account for patient clustering within physician practices.
  
  
  RESULTS
  Of the 705 individuals approached, 420 (59.6%) were enrolled. Incident MAE rates at the two-, 14- and 30-day follow-ups were 17.3% (95% credible interval [CrI] 8.1% to 30%), 10.5% (95% CrI 2.9% to 23.7%) and 3.2% (95% CrI 0.01% to 19.8%), respectively. The 30-day rate of health resources utilization was 1.7%, with 0.95% of participants seeking the services of a physician. No predictors of the cumulative 30-day incidence of MAEs were identified.
  
  
  CONCLUSIONS
  The incidence of MAEs was highest in the 48 h following colonoscopy and uncommon after two weeks, supporting the Canadian Association of Gastroenterology's recommendation for assessment of late complications at 14 days. Predictors of new onset of MAEs were not identified, but wide CrIs did not rule out possible associations. Although <1% of participants reported consulting a physician for MAEs, this figure may represent a substantial number of visits given the increasing number of colonoscopies performed annually.
  
  
  CONCLUSIONS
  Postcolonoscopy MAEs are common, occur mainly in the first two weeks postcolonoscopy and result in little use of health resources.
authors.forename: Vladimir
authors.initials: V
authors.lastname: Marquez Azalgara
authors.forename: Maida J
authors.initials: MJ
authors.lastname: Sewitch
authors.forename: Lawrence
authors.initials: L
authors.lastname: Joseph
authors.forename: Alan N
authors.initials: AN
authors.lastname: Barkun
mesh_terms: D000368:Aged; D003113:Colonoscopy / Q000009:adverse effects* / Q000706:statistics & numerical data; D004636:Emergency Service, Hospital / Q000706:statistics & numerical data; D005260:Female; D005762:Gastroenterology / Q000706:statistics & numerical data; D006295:Health Resources / Q000706:statistics & numerical data*; D015277:Hotlines / Q000706:statistics & numerical data; D006801:Humans; D015994:Incidence; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D009726:Nurses / Q000706:statistics & numerical data; D009819:Office Visits / Q000706:statistics & numerical data; D010595:Pharmacists / Q000706:statistics & numerical data; D011183:Postoperative Complications / Q000453:epidemiology*; D011320:Primary Health Care / Q000706:statistics & numerical data; D011446:Prospective Studies; D011792:Quebec / Q000453:epidemiology; D013997:Time Factors