Research indicates that about 60% of influenza-related hospitalizations occur in adults aged 65 and older during most influenza seasons in the United States. Many of these patients are frail and at increased risk for functional decline. However, few studies have assessed the need for extended care admissions due to functional decline from influenza-associated hospitalizations among community-dwelling older adults. Additionally, whereas studies have shown that prompt treatment with influenza antiviral agents can reduce the duration of illness and prevent influenza-related complications, data are limited on the benefit of antiviral treatment in this patient population.


Examining the Issue

For a study published in Clinical Infectious Diseases, Nancy M. Bennett, MD, MS, and colleagues analyzed predictors of extended care and the potential mitigating effect of antiviral treatment among community-dwelling patients aged 65 and older. Participants were hospitalized with laboratory-confirmed influenza during the 2010-2011, 2011-2012, and 2012-2013 influenza seasons. Extended care was defined as placement in a skilled nursing facility on hospital discharge. Treatment was categorized as early (4 days or less) or late (more than 4 days) in reference to the date of illness onset. “We also assessed a series of variables to determine which predicted loss of functional status and extended care placement,” says Dr. Bennett.

The researchers found that among more than 6,500 participants, 18% were discharged from the hospital to extended care facilities. “These patients went from living independently to requiring significant care,” Dr. Bennett adds. A univariate analysis found the following to be predictors of discharge to extended care:

  • Increasing age (10% among those aged 65 to 74, 16% for those aged 75 to 84, and 30% for those older than 85).
  • Caucasian race.
  • Underlying chronic medical conditions, particularly cardiovascular disease and neurologic disorders.
  • Low BMI.
  • Receipt of influenza vaccination.
  • Antiviral treatment.

“We found a stronger association between influenza A and discharge to extended care when compared with influenza B, but the difference was small,” says Dr. Bennett. “Site of care was also a predictor of extended care placement on univariate analysis, with a large variation from site to site. For example, in Connecticut, 27% of the patients were admitted to extended care after hospitalization, compared with a rate of only 12% in Rhode Island.” Patients requiring extended care were also more likely to have complications, including community-acquired pneumonia (35% vs 26%), encephalitis (4% vs 1%), ICU admission (25% vs 10%), mechanical ventilation (11% vs 2%), and hospitalization for more than 5 days (72% vs 29%) when compared with those not requiring extended care.

However, early treatment reduced the likelihood of requiring extended care after hospital discharge, says Dr. Bennett (Figure). “Early treatment also reduced patients’ length of stay,” she explains. “This is particularly important because prolonged length of stay in a patients older than 65 increases the risk for loss of functional status and for requiring extended care.”

Even after a multivariate analysis was conducted to control for relationships between the studied variables, antiviral therapy—particularly when delivered early—remained a strong predictor of not requiring extended care. “Whereas age, neurologic disease, ICU admission, and pneumonia on admission remained strong predictors of requiring extended care, the other predictors we found within the univariate analysis dropped out of the model and were determined to not be as important,” explains Dr. Bennett.


Assessing the Implications

The study findings highlight the importance of considering influenza as a diagnosis among elderly patients who present during flu season, according to Dr. Bennett. “Often, older patients are admitted to the hospital with what is presumed to be pneumonia or an exacerbation of congestive heart failure or coronary artery disease when, in fact, their symptoms are caused by influenza,” she says. “We encourage physicians to test for influenza when older patients present for care and to consider early antiviral treatment.”

Dr. Bennett also explains that the benefits of early treatment correlate with how early into the illness patients seek care. “Although patients die from influenza, it’s often underappreciated by providers and patients alike. During influenza season, older patients should be informed that they may have influenza if they have respiratory symptoms accompanied by headache, muscle pain, and fever, and they should be encouraged to seek medical care early in their illness.”