Can We Extend the Influenza Vaccination Season? the San Diego Influenza Coverage Extension Project

Background: The San Diego Influenza Coverage Extension (SDICE) project aims to improve influenza vaccination rates in late season (January and February) for two at-risk populations since interest in immunization usually wanes, but disease often peaks during this time each year. 

Objectives: To compare patient/parent self report with chart documentation.  To determine if differences in influenza vaccine delivery exist among three types of practices: large medical groups, single-office practices, or community health centers. 

Methods: Parents of children 6-60 months and adults 50 years and over were recruited and interviewed during January-March 2009 in 16 medical offices.  Chart reviews and verification of patient survey data, conducted between April-June 2009, used systematic or random sample of records. 

Results: Patient-reported influenza coverage varied from 60% to 70% for children, and 54% to 75% for adults.  Low agreement with chart audits was observed with coverage rates for children ranging from 46% to 56% and 19% to 45% for adults.  Chart identified missed opportunity rates ranged from 35% to 60% for children and 73% to 93% for adults.  Determination of these rates was complicated by incomplete documentation of influenza vaccines received outside these medical practices.  Differences were also seen with respect to patient receptiveness to late season vaccination: 21% to 71% of parents of unvaccinated children would have received a flu shot for their child had it been offered, while 19% to 51% of unvaccinated adults said the same for themselves.

Conclusions: Influenza coverage rates vary widely among the type of practice.  Many patients seem receptive to late season vaccination.  While discrepancies between patient recall and medical records are not surprising, interventions aimed at educating the patient and streamlining documentation practices are needed.