The impact of federal warnings on publically funded desmopressin utilization among children in Ontario.

OBJECTIVE

To determine whether safety warnings issued by health regulatory agencies regarding desmopressin treatment influenced treatment rates among children.

PATIENT POPULATION AND 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.

CONCLUSION

Safety warnings issued by regulatory agencies dramatically influenced desmopressin use among Ontario's children.