Objective: To estimate the impact of missed opportunities on influenza vaccination coverage among 6- through 23-month-old children who sought medical care during the 2004–2005 influenza season.
Design: Retrospective cohort study.
Setting: Fifty-two primary care practice sites located in Rochester, New York, Nashville, Tennessee, and Cincinnati, Ohio.
Participants: Children 6 through 23 months of age.
Methods/Outcome Measure: Charts were reviewed and data collected on influenza vaccinations, type of health care visit (well child or other), and presence of illness symptoms. Missed opportunity was defined as a practice visit by an eligible child during influenza season, when vaccine was available, but during which the child did not receive an influenza vaccination. Vaccine was assumed to be available between the first and last dates influenza vaccination was recorded at that practice. Each child was classified as fully vaccinated, partially vaccinated, or unvaccinated.
Results: Data were analyzed for 1724 children, 6 through 23 months of age. Most children (62.0%) had at least 1 missed opportunity during this period. Among children with any missed opportunities, 12.8% were fully and 29.8% were partially vaccinated. Overall, 33.6% of the missed opportunities occurred during well child visits and 66.4% during other types of visits; 75% occurred when no other vaccines were given. Eliminating all missed opportunities would have increased full vaccination coverage from 30.3% to 49.9%.
Conclusions: Missed opportunities for influenza vaccination are frequent. Reducing missed opportunities could significantly increase influenza vaccination rates and should be a goal in each practice.