Geographic variation in influenza vaccination among U.S. nursing home residents: A national study

Geospatial Distribution of Racial Disparities in Influenza Vaccination in Nursing Homes

OBJECTIVES

This study aimed to assess the distribution of racial disparities in influenza vaccination between White and Black short-stay and long-stay nursing home residents among states and hospital referral regions (HRRs).

DESIGN

Retrospective cohort study.

SETTING AND PARTICIPANTS

We included short-stay and long-stay older adults residing in US nursing homes during influenza seasons between 2011 and 2018. Included residents were aged ≥65 years and enrolled in Traditional Medicare. Analyses were conducted using resident-seasons, whereby residents could contribute to one or more influenza seasons if they resided in a nursing home across multiple seasons.

METHODS

Our comparison of interest was marginalized vs privileged racial group membership measured as Black vs White race. We obtained influenza vaccination documentation from resident Minimum Data Set assessments from October 1 through June 30 of a particular influenza season. Nonparametric g-formula was used to estimate age- and sex-standardized disparities in vaccination, measured as the percentage point (pp) difference in the proportions of individuals vaccinated between Black and White nursing home residents within states and HRRs.

RESULTS

The study included 7,807,187 short-stay resident-seasons (89.7% White and 10.3% Black) in 14,889 nursing homes and 7,308,111 long-stay resident-seasons (86.7% White and 13.3% Black) in 14,885 nursing homes. Among states, the median age- and sex-standardized disparity between Black and White residents was 10.1 percentage points (pps) among short-stay residents and 5.3 pps among long-stay residents across seasons. Among HRRs, the median disparity was 8.6 pps among short-stay residents and 5.0 pps among long-stay residents across seasons.

CONCLUSIONS AND IMPLICATIONS

Our analysis revealed that the magnitudes of vaccination disparities varied substantially across states and HRRs, from no disparity in vaccination to disparities in excess of 25 pps. Local interventions and policies should be targeted to high-disparity geographic areas to increase vaccine uptake and promote health equity.

Geographic Variation in Influenza Vaccination Disparities Between Hispanic and Non-Hispanic White US Nursing Home Residents

BACKGROUND

Disparities in influenza vaccination exist between Hispanic and non-Hispanic White US nursing home (NH) residents, but the geographic areas with the largest disparities remain unknown. We examined how these racial/ethnic disparities differ across states and hospital referral regions (HRRs).

METHODS

This retrospective cohort study included >14 million short-stay and long-stay US NH resident-seasons over 7 influenza seasons from October 1, 2011, to March 31, 2018, where residents could contribute to 1 or more seasons. Residents were aged ≥65 years and enrolled in Medicare fee-for-service. We used the Medicare Beneficiary Summary File to ascertain race/ethnicity and Minimum Data Set assessments for influenza vaccination. We calculated age- and sex-standardized percentage point (pp) differences in the proportions vaccinated between non-Hispanic White and Hispanic (any race) resident-seasons. Positive pp differences were considered disparities, where the proportion of non-Hispanic White residents vaccinated was greater than the proportion of Hispanic residents vaccinated. States and HRRs with ≥100 resident-seasons per age-sex stratum per racial/ethnic group were included in analyses.

RESULTS

Among 7 442 241 short-stay resident-seasons (94.1% non-Hispanic White, 5.9% Hispanic), the median standardized disparities in influenza vaccination were 4.3 pp (minimum, maximum: 0.3, 19.2; n = 22 states) and 2.8 pp (minimum, maximum: -3.6, 10.3; n = 49 HRRs). Among 6 758 616 long-stay resident-seasons (93.7% non-Hispanic White, 6.5% Hispanic), the median standardized differences were -0.1 pp (minimum, maximum: -4.1, 11.4; n = 18 states) and -1.8 pp (minimum, maximum: -6.5, 7.6; n = 34 HRRs).

CONCLUSIONS

Wide geographic variation in influenza vaccination disparities existed across US states and HRRs. Localized interventions targeted toward areas with high disparities may be a more effective strategy to promote health equity than one-size-fits-all national interventions.

Geographic variation in influenza vaccination among U.S. nursing home residents: A national study

Objectives

Estimates of influenza vaccine use are not available at the county level for U.S. nursing home (NH) residents but are critically necessary to guide the implementation of quality improvement programs aimed at increasing vaccination. Furthermore, estimates that account for differences in resident characteristics between counties are unavailable. We estimated risk‐standardized vaccination rates (RSVRs) among short‐ and long‐stay NH residents by U.S. county and identified drivers of geographic variation.

Methods

We conducted a retrospective cohort study utilizing 100% of 2013–2015 fee‐for‐service Medicare claims, Minimum Data Set assessments, Certification and Survey Provider Enhanced Reports, and Long‐Term Care: Facts on Care in the U.S. We separately evaluated short‐stay (<100 days) and long‐stay (≥100 days) residents aged 65 and older across the 2013–2014 and 2014–2015 influenza seasons. We estimated RSVRs via hierarchical logistic regression adjusting for 32 resident‐level covariates. We then used multivariable linear regression models to assess associations between county‐level NHs predictors and RSVRs.

Results

The study cohort consisted of 2,817,217 residents in 14,658 NHs across 2798 counties. Short‐stay residents had lower RSVRs than long‐stay residents (2013–2014: median [interquartile range], 69.6% [62.8–74.5] vs 84.0% [80.8–86.4]), and there was wide variation within each population (range, 11.4–89.8 vs 49.1–92.6). Several modifiable facility‐level characteristics were associated with increased RSVRs, including higher registered nurse to total nurse ratio and higher total staffing for licensed practical nurses, speech‐language pathologists, and social workers. Characteristics associated with lower RSVRs included higher percentage of residents restrained, with a pressure ulcer, and NH‐level hospitalizations per resident‐year.

Conclusions

Substantial county‐level variation in influenza vaccine use exists among short‐ and long‐stay NH residents. Quality improvement interventions to improve vaccination rates can leverage these results to target NHs located in counties with lower risk‐standardized vaccine use.