Cath Lab Digest

Results of a study that assessed diarrhea-associated healthcare use between children vaccinated with the pentavalent rotavirus vaccine (RV5) and those unvaccinated [N Engl J Med. 2011;365(12):1108-1117] found a decline in rates of diarrhea-associated hospitalizations and ambulatory visits as well as medical expenditures among children <5 years of age vaccinated with RV5. Along with confirming other reports of reduced rotavirus activity in the United States after implementation of rotavirus vaccination in 2006, the current findings show substantial reductions in rotavirus-coded hospitalizations in children vaccinated with RV5 compared with those unvaccinated.

The study used MarketScan databases to assess diarrhea-associated healthcare use from July 2007 through June 2009 after implementation of RV5 vaccination for children <5 years of age compared with July 2001 through June 2006 before RV5 vaccination became routine. Derived from insurance claims, MarketScan data contain information from both public and private health plans. Data on diarrhea-associated healthcare events and use of RV5 coverage from January 2006 to June 2009 were identified. Overall, data from about 2 million children <5 years of age were captured during the study period.

Data from January 2006 to June 2009 showed that 32% of nearly 300,000 children <5 years of age from 37 states had received at least 1 dose of RV5 by December 31, 2008. The majority of children covered were <1 year of age (73%), with 64% of the 1-year-olds covered and 8% of children 2 to 4 years of age covered.

The study found that rates of hospitalization for diarrhea fell from 52 cases per 10,000 person-years during 2001-2006 prior to routine vaccination to 35 cases and 39 cases per 10,000 person-years between 2007-2008 and 2008-2009, respectively. From 2001 through 2006, this represents a relative reduction in diarrhea-associated hospitalizations by 33% (95% confidence interval [CI], 31-35) in 2007-2008 and by 25% (95% CI, 23-27) in 2008-2009.

The study also looked at direct and indirect vaccine benefits. For direct benefits, it compared rates of rotavirus-coded hospitalizations and diarrhea-associated healthcare use during January through June (when rotavirus is most prevalent) in 2008 and 2009 among vaccinated versus unvaccinated children. Results of this analysis showed the largest reduction found in the study, with relative reductions from 2001-2006 by 75% (95% CI, 72-77) in 2007-2008 and by 60% (95% CI, 58-63) in 2008-2009.

Compared with unvaccinated children, vaccinated children had 89% fewer rotavirus-coded hospitalizations in both of the 2 postvaccine rotavirus seasons (January-June 2007-2008 and January-June 2008-2009). Significant reductions for vaccinated children compared with unvaccinated children during these 2 periods were also found for hospitalization for diarrhea of any cause (44% and 58%, respectively), for emergency department visits (37% and 48%), and outpatient visits (9% and 12%).