SAN DIEGO – Over half of hospitalized, influenza-related deaths occurred within 30 days of discharge, according to a study presented at an annual scientific meeting on infectious diseases.
As physicians and pharmaceutical companies attempt to measure the burden of seasonal influenza, discharged patients are currently not considered as much as they should be, according to investigators.
Among 968 deceased patients studied, 444 (46%) died in hospital, while 524 (54%) died within 30 days of discharge.
Investigators conducted a retrospective study of 15,562 patients hospitalized for influenza-related cases between 2014 and 2015, as recorded in Influenza-Associated Hospitalizations Surveillance (FluSurv-NET), a database of the Centers for Disease Control and Prevention.
The majority of the studied patients were women (55%) and the majority were white.
Those who died were more likely to have been admitted to the hospital immediately after influenza onset, with 26% of those who died after discharge and 22% of those who died in hospital having been admitted the same day. In contrast, 13% of those who lived past 30 days were admitted immediately after onset.
A total of 46% of those who died after hospitalization had a length of stay longer than 1 week, compared to 15% of those who lived.
Among patients who died after discharge, 356 (68%) died within 2 weeks of discharge, with the highest number of deaths occurring within the first few days, according to presenter Craig McGowan of the Influenza Division of the CDC in Atlanta.
Age also seemed to be a possible mortality predictor, according to Mr. McGowan and his fellow investigators. “Those who died were more likely to be elderly, and those who died after discharge were even more likely to be 85 [years or older] than those who died during their influenza-related hospitalizations,” said Mr. McGowan, who added that patients aged 85 years and older made up more than half of those who died after discharge.
Patients who died in hospital were significantly more likely to have influenza listed as a cause of death. Overall, influenza-related and non–influenza-related respiratory issues were the two most common causes of death listed on death certificates of patients who died during hospitalization or within 14 days of discharge, while cardiovascular or other symptoms were listed for those who died between 15 and 30 days after discharge.
Admission and discharge locations among patients who did not die were almost 80% from a private residence to a private residence, while observations of those who died revealed a different pattern. “Those individuals who died after discharge were almost evenly split between admission from a nursing home or a private residence,” Mr. McGowan said. “Those who were admitted from the nursing home were almost exclusively discharged to either hospice care or back to a nursing home.”
Mr. McGowan noted rehospitalization to be a significant factor among those who died, with 34% of deaths occurring back in the hospital after initial discharge.
Influenza testing of studied patients was given at clinicians’ discretion, which may make the sample not generalizable to the overall influenza population, and the investigators included only bivariate associations, which means there were likely confounding effects that could not be accounted for.
Mr. McGowan and his fellow investigators plan to expand their research by determining underlying causes of death in these patients, to create more accurate estimates of influenza-associated mortality.
Mr. McGowan reported no relevant financial disclosures.
SOURCE: McGowan, C., et al., ID Week 2017, Abstract 951.