Vaccines Effective in Nursing Home Residents

April 21, 2004

Andrew Bowser

April 21, 2004 (Philadelphia) — Nursing home residents who receive either pneumococcal or influenza vaccine have a significantly reduced risk of hospitalization, according to preliminary results of a large retrospective cohort study presented here at the annual meeting of the Society for Healthcare Epidemiology in America.

Older individuals living in facilities with high influenza vaccination rates were also at significantly lower risk of being hospitalized, regardless of whether they were vaccinated themselves, reported John A. Jernigan, MD, MS, from the Centers for Disease Control and Prevention (CDC) in Atlanta, Georgia.

"Wider implementation of standing orders programs, or other effective interventions to increase vaccination rates, are needed," Dr. Jernigan told attendees at the meeting, noting that only 62% of nursing home residents in this study received influenza vaccine, and less than 50% received pneumococcal vaccine, well below the 90% goal outlined in the federal government's Healthy People 2010 initiative.

Previous studies have shown that influenza vaccination reduces rates of hospitalization and rates of pneumonia, respiratory illness, and death in the elderly. But the efficacy of polysaccharide pneumococcal vaccine in this population is less clear, according to the lead author of the study, Sophia V. Kazakova, MD, PhD, MPH, an Epidemic Intelligence Service officer at the CDC.

"This is first study of nursing home residents to demonstrate a significant protective effect of individual pneumococcal vaccination on clinical outcomes," Dr. Kazakova told Medscape. "So far, we have not had much data and evidence supporting this, which could be one of reasons why we have low vaccination rate [in nursing home residents], even though vaccination has been recommended."

The low vaccination rates in this study reflect a larger trend: according to a national survey from the National Center for Health Statistics, the rates of influenza and pneumococcal vaccination in nursing homes was 66% and 38%, respectively, in 1999, the latest year for which data are available.

The their current study, Dr. Kazakova and colleagues evaluated the effect of vaccination using data from 277 nursing homes in 14 states. They randomly sampled data on 100 residents from each home during the 2000 to 2001 and 2001 to 2002 influenza seasons (November through January), including on-site record reviews, to determine vaccination status. That information was coupled with Medicare claims data on hospitalizations, among other patient-specific information.

Overall, the investigators reviewed data on 18,397 patients from the 2000 to 2001 season and 17,302 patients from the 2001 to 2002 season. Exclusion criteria included terminal illness or hospitalization within 14 days of vaccination.

For the 2000 to 2001 season, 25.3% of vaccinated residents were hospitalized compared with 37.1% of unvaccinated residents (relative risk [RR], 0.68; 95% confidence interval [CI], 0.65 - 0.71; P < .001). Likewise, hospitalization for respiratory disease was less common among the vaccinated residents (9.1% vs. 17.9%; RR, 0.51; 95% CI, 0.47 - 0.55; P < .001). Similar results were seen in the 2001 to 2002 season.

Multivariate analysis, controlling for comorbid conditions, age, and other factors, found that both influenza and pneumococcal vaccination were "independently protective" of individual vaccines for both study periods, Dr. Jernigan said in his presentation. Residing in a facility with high influenza immunization rates (80% or greater) was "protective against all-cause hospitalization, independent of individual vaccine status," he added.

There have been conflicting reports about the efficacy of pneumococcal vaccine in elderly individuals, the investigators said. While these results provide some evidence of benefit for pneumococcal vaccine in the elderly, at least for nursing home patients, "it's important to know that the data we are presenting is preliminary," Dr. Kazakova told Medscape. "We will continue looking into this."

The authors report no pertinent financial disclosures.

SHEA 14th Annual Scientific Meeting: Abstract 61. Presented April 18, 2004.

Reviewed by Gary D. Vogin, MD

Andrew Bowser is a freelance writer for Medscape.


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