Underused pneumococcal, flu shots save lives in LTC

CDC study shows broad protective effect

Though somewhat reluctant to trumpet the findings, the Centers for Disease Control and Prevention (CDC) has unveiled the first study demonstrating the significant protective effect of individual pneumococcal vaccination on hospitalization among nursing home residents.

The study also confirmed the important roleof individual influenza vaccination in preventing hospitalization in this population and suggests that residing in a facility with a high influenza vaccination rate independently reduces the risk of hospitalization. Programs to increase pneumococcal and influenza vaccination among nursing home residents should be encouraged, the CDC concluded.1

John Jernigan, MD, medical epidemiologist in the CDC division of healthcare quality promotion, presented the findings recently in Philadelphia at the annual conference of the Society for Healthcare Epidemiology of America (SHEA). However, Jernigan was noncommittal when asked whether the apparently encouraging findings warrant a reemphasis of existing guidelines to immunize more residents.

"The guidelines already exist for vaccinating this population," he told Hospital Infection Control. "We think these data add to the supporting evidence. A better understanding of what the barriers to vaccination are is important. Perhaps these data could help [determine] whether there may be systems problems in place."

However, in presenting the paper at SHEA, Jernigan cited the politically charged term "patient safety" as among the public health implications. The study found that for influenza in particular, even nonimmunized nursing home residents are protected if 80% of the other residents have been vaccinated.

"Nursing home residents who receive pneumococcal and/or influenza vaccination are at significantly reduced risk of hospitalization," Jernigan told SHEA attendees. "The public health implications of this study are that failure to vaccinate residents of long-term care facilities is a patient safety issue; a better understanding of barriers to vaccination in this setting is needed, and wider implementation of standing orders [for vaccination are needed]."

Describing the scope of the problem, Jernigan said there currently are 1.6 million residents living in 17,000 long-term care facilities in the United States. "Influenza and pneumonia are a major source of morbidity and mortality in these settings," he said. "The incidence of invasive pneumococcal disease is approximately four times higher among long-term care facility residents compared to other older adults in the community. About 90% of influenza-related deaths occur among the elderly. Yet both influenza and pneumococcal vaccination rates remain low among residents of nursing homes."

Although there is good evidence of the efficacy of influenza vaccine to reduce respiratory illness, hospitalization, and pneumonia, there is conflicting evidence regarding the efficacy of polysaccharide pneumococcal vaccine among older adults, he said. Studies that exclusively examine the impact of the vaccine on long-term care residents are rare, usually small, and lack statistical power.

Jernigan and colleagues conducted a retrospective cohort study to examine the impact of pneumococcal and influenza vaccination on risk of hospitalization among nursing home residents during two recent influenza seasons.1 Individual pneumococcal and influenza vaccination status was assessed for 2000-2001 and 2001-2002 cohorts randomly selected from 277 nursing homes in 14 states.

Of the 18,397 residents in the 2000-2001 cohort, 6,534 (35.5%) and 5,058 (29.2%) were hospitalized respectively during the influenza seasons. In both cohorts, about 40% received pneumococcal vaccination and 60% received influenza vaccination. In the first cohort, receipt of pneumococcal vaccination was independently associated with reduced risk of all-cause hospitalization and hospitalization for respiratory illness.

Influenza vaccination also was protective against all-cause hospitalization and hospitalization for respiratory illness. In addition, residing in a facility where at least 80% of residents received influenza vaccination was independently associated with a reduced risk of all-cause hospitalization. However, such independent facilitywide protection was not found for the pneumococcal vaccine. Similar results were obtained for the second cohort.

"Both individual influenza and pneumococcal vaccination were independently protective in both study years," Jernigan said.

Reference

1. Kazakova SK, Curtis A, Bratzle D, et al. Impact of pneumococcal and influenza vaccination on the risk of hospitalization among nursing home residents Abstract 64. Presented at the Society for Healthcare Epidemiology of America annual conference. Philadelphia; April 2004.