Medicare claims versus beneficiary self-report for influenza vaccination surveillance.

BACKGROUND: Although self-reported influenza vaccination status is routinely used in surveillance to estimate influenza vaccine coverage, Medicare data are becoming a promising resource for influenza surveillance to inform vaccination program management and planning. PURPOSE: To evaluate the concordance between self-reported influenza vaccination and influenza vaccination claims among Medicare beneficiaries. METHODS: This study compared influenza vaccination based upon Medicare claims and self-report among a sample of Medicare beneficiaries (N=9,378) from the 2011 Medicare Current Beneficiary Survey, which was the most recent year of data at the time of analysis (summer 2013). Sensitivity, specificity, positive predictive value, and negative predictive value were calculated using self-reported data as the referent standard. Logistic regression was used to compute the marginal mean proportions for whether a Medicare influenza vaccination claim was present among beneficiaries who reported receiving the vaccination. RESULTS: Influenza vaccination was higher for self-report (69.4%) than Medicare claims (48.3%). For Medicare claims, sensitivity=67.5%, specificity=96.3%, positive predictive value=97.6%, and negative predictive value=56.7%. Among beneficiaries reporting receiving an influenza vaccination, the percentage of beneficiaries with a vaccination claim was lower for beneficiaries who were aged <65 years, male, non-Hispanic black or Hispanic, and had less than a college education. CONCLUSIONS: The classification of influenza vaccination status for Medicare beneficiaries can differ based upon survey and claims. To improve Medicare claims-based surveillance studies, further research is needed to determine the sources of discordance in self-reported and Medicare claims data, specifically for sensitivity and negative predictive value.

Flu shots and the characteristics of unvaccinated elderly Medicare beneficiaries.

KEY FINDINGS: Data from the Medicare Current Beneficiary Survey, 2009. • Overall, 73% of Medicare beneficiaries aged 65 years and older reported receiving a flu shot for the 2008 flu season, but vaccination rates varied by socio-demographic characteristics. Flu vaccination was lowest for beneficiaries aged 65-74 years old, who were non-Hispanic Blacks and Hispanics, were not married, had less than a high school education, or who were eligible for Medicaid (i.e., dual eligibles). • Healthcare utilization and personal health behavior were also related to vaccination rates, with current smokers and those with no hospitalizations or physician visits being less likely to be vaccinated. • Among those beneficiaries who reported receiving a flu shot, 59% received it in a physician's office or clinic, with the next most common setting being in the community (21%); e.g., grocery store, shopping mall, library, or church. • Among those beneficiaries who did not receive a flu shot, the most common reasons were beliefs that the shot could cause side effects or disease (20%), that they didn't think the shot could prevent the flu (17%), or that the shot wasn't needed (16%). Less than 1% reported that they didn't get the flu shot because of cost. Elderly persons (aged 65 years and older) are at increased risk of complications from influenza, with the majority of influenza-related hospitalizations and deaths occurring among the elderly (Fiore et al., 2010). Most physicians recommend their elderly patients get a flu shot each year, and many hospitals inquire about elderly patient's immunization status upon admission, providing a vaccination if requested. The importance of getting a flu shot is underscored by the Department of Health and Human Services' Healthy People initiative, which has set a vaccination goal of 90% for the Nation's elderly by the year 2020 (Department of Health and Human Services [DHHS], 2011). Although all costs related to flu shots are covered by Medicare, requiring no co-pay on the part of the beneficiary (Centers for Medicare and Medicaid Services, 2011), for the 2008 flu season, only 73% of non-institutionalized Medicare beneficiaries, aged 65 years and older, reported receiving one. This report presents the most recent data on flu vaccination rates among non-institutionalized elderly Medicare beneficiaries and their association with socio-demographic and personal health characteristics. The report also describes the places beneficiaries received their flu shot and, for those not getting vaccinated, the reasons reported for not doing so.