Incidence, Key Factors Contributing to Hospital Readmissions in Patients With Laboratory-Confirmed Influenza

According to results published in a recent issue of Journal of Infectious Diseases, hospitalization due to influenza is linked with a greater probability of readmission within 30 days and 1 year most commonly as a result of cardiovascular, respiratory, and infectious processes. Researchers conducted a retrospective study using Tennessee Emerging Infections Program Influenza Surveillance data from 2006 to 2016 and the concurrent TN Hospital Discharge Data System. They evaluated demographic characteristics and outcomes to improve understanding of the frequency and factors correlated with hospital readmissions.

Of the 2,897 patients with a laboratory-confirmed influenza hospitalization:

• 409 (14%) and 1,364 (47%) had at least one hospital readmission within 30 days and 1 year of the influenza hospitalization respectively.
• Several readmissions occurred in 739 patients (54%). The readmission group was older, predominantly female, and had more comorbidities than patients not hospitalized. In contrast, the percentage of patients readmitted for any cause was 8% and 29% within 30 days and 1 year, respectively.
• Smoking status and race were not statistically substantial between patients in these 2 groups.
• Pneumonia, acute COPD/asthma exacerbation, septicemia, acute respiratory failure, and acute renal failure were the most frequent causes for readmission at 30 days.
• Of the patients readmitted within 30 days, 28% had an infectious disease diagnosis, 14% had a pulmonary disease diagnosis, and 11% had a cardiovascular diagnosis as their primary diagnosis.
• Underlying cardiovascular disease, lung disease, kidney disease, diabetes, immunosuppression, and liver disease were associated with increased risk of readmission during the subsequent year.
• Of patients aged > 65 years, 27% of readmissions were due to a primary infectious disease diagnosis, 17% cardiovascular disease diagnosis, and 14% a pulmonary disease diagnosis within 1 year.
• Patients who were readmitted were also more likely to have been vaccinated than those who were not (48% vs 37%; P <.01).
• Researchers noted that further studies into influenza vaccination and hospital readmission are necessary, as influenza vaccination was not linked with a lower risk for readmission.

The authors concluded that after an admission with laboratory-confirmed influenza, there is an elevated likelihood of readmission within 30 days and 1 year adding to the morbidity of influenza. Lead author, Dobrzynski and colleagues also noted that, “The comorbidities could be an important link to understanding these readmissions. Further studies are needed to elucidate conditions that could be targeted to decrease readmissions and to determine the role of vaccination in prevention of readmission.”

References

• Dobrzynski DM, Ndi DN, Zhu Y, Markus T, Schaffner W, Talbot HK. Hospital readmissions following laboratory-confirmed influenza hospitalization [published online March 17, 2020]. J Infect Dis. doi:10.1093/infdis/jiaa117.
• Gupta Sweta. Frequency and Factors Associated With Hospital Readmissions Due to Influenza. Infectious Disease Advisor. https://www.infectiousdiseaseadvisor.com/home/topics/respiratory/influenza/patients-who-require-hospitalization-for-the-flu-often-need-readmission-later/ . Published April 3, 2020. Accessed April 6, 2020.

Yvette C. Terrie, R.Ph., Consultant Pharmacist and Medical Writer and creator of A Pharmacist’s Perspective (https://apharmacistsperspective.blogspot.com  ).