Why do not patients receive influenza vaccine in December and January?

Influenza vaccination levels in older patients have changed little since the mid-1990s. Despite frequent health care visits by a majority of older persons, many missed opportunities continue to occur. Patients were eligible for the study if they were age 50 and older, had not received influenza vaccine during the current season and were making a scheduled visit to one of the 13 study sites in California, New York, or New Mexico for purposes other than vaccination. Through direct observation, we determined if office staff inquired about vaccination status, discussed vaccination, or both. We defined missed opportunities as failure to administer influenza vaccine to patients for whom it was indicated. Missed opportunities increased steadily from October to January ( P < 0.0001), and were more common when there was no inquiry or discussion ( P < 0.00001), among patients aged 50–64 ( P < 0.0001) and in California and New Mexico ( P = 0.001). A classification tree analysis revealed that lack of inquiry and week of visit contributed most to missed opportunities. Early in the vaccination season, missed opportunities were uncommon and specific inquiries into or discussion of vaccination did not appear necessary. In December and January, patients tended to be vaccinated only when vaccination was addressed during the visit. Efforts to remind patients about vaccination later in the vaccination season may be essential to achieving higher coverage in the U.S.