title: The impact of federal warnings on publically funded desmopressin utilization among children in Ontario.
abstract: OBJECTIVE
  To determine whether safety warnings issued by health regulatory agencies regarding desmopressin treatment influenced treatment rates among children.
  
  
  METHODS
  We conducted a time-series analysis using health administrative data from Ontario, Canada, between January 1, 2003 and March 31, 2010. We examined desmopressin prescribing rates among children (<13 years) and investigated the impact of a United States Food and Drug Administration warning (December 2007) and a subsequent Health Canada warning (July 2008) on these rates. A secondary analysis stratified rates according to route of administration.
  
  
  RESULTS
  On average, quarterly desmopressin treatment rates were 29.8% lower following the two warnings (4.7 per 1000 population) compared with the period prior to warnings being issued (6.7 per 1000 population). Structural break analyses identified a significant decrease in overall desmopressin prescribing rates in Q3 2008, with the 95% confidence interval (CI) spanning both safety warnings (Q4 2007 to Q1 2009). A secondary analysis of prescribing rates for oral formulations found consistent results (structural break Q4 2008, 95% CI Q2 2007 to Q2 2009). The average quarterly prescribing rate of intranasal formulations declined by 73.1% following the warnings compared with the period preceding the warnings.
  
  
  CONCLUSIONS
  Safety warnings issued by regulatory agencies dramatically influenced desmopressin use among Ontario's children.
authors.affiliation: The Institute for Clinical Evaluative Sciences, Toronto, ON, Canada. tara.gomes@ices.on.ca
authors.forename: Tara
authors.initials: T
authors.lastname: Gomes
authors.forename: David N
authors.initials: DN
authors.lastname: Juurlink
authors.forename: Ian
authors.initials: I
authors.lastname: Moore
authors.forename: Jonathon L
authors.initials: JL
authors.lastname: Maguire
authors.forename: Muhammad M
authors.initials: MM
authors.lastname: Mamdani
mesh_terms: D000293:Adolescent; D050034:Antidiuretic Agents / Q000494:pharmacology; D002648:Child; D003430:Cross-Sectional Studies; D003894:Deamino Arginine Vasopressin / Q000191:economics / Q000494:pharmacology*; D016527:Drug Costs / Q000331:legislation & jurisprudence*; D004348:Drug Labeling / Q000191:economics / Q000331:legislation & jurisprudence*; D011307:Drug Prescriptions / Q000191:economics* / Q000706:statistics & numerical data*; D017723:Drug Utilization Review / Q000331:legislation & jurisprudence*; D005380:Financing, Government / Q000331:legislation & jurisprudence*; D006801:Humans; D009864:Ontario
chemical_list: D050034:Antidiuretic Agents; D003894:Deamino Arginine Vasopressin