Antiviral use is associated with a decrease in the rate of influenza-related complications, health care resource utilization, and costs

Reduced mortality, complications, and economic burden among medicare beneficiaries receiving influenza antivirals

INTRODUCTION

Antiviral therapy may be underutilized in patients at high risk for increased clinical and economic burden (e.g. older adults). We aimed to examine the benefits associated with antiviral treatment of seasonal influenza among treated and untreated Medicare beneficiaries.

METHODS

This retrospective study of Medicare Claims Research Identifiable Files identified patients ≥66 years old with an influenza diagnosis in outpatient setting between October 2016-March 2019 (flu seasons 2016-2018). Index date defined as date of first claim with influenza diagnosis; baseline as the 12 months pre-index. Treated patients received antivirals ≤2 days from index. Untreated patients had no antivirals ≤6 months post-index. Treated/untreated patients were 1:1 propensity score matched. Outcomes (death, all-cause and respiratory-related healthcare resource utilization [HCRU] and costs) were assessed until death or up to 6 months post-index. Descriptive statistics were reported; Kaplan-Meier estimation was used for survival over time.

RESULTS

Among 116,901 matched patient pairs, all-cause mortality within 6 months from index diagnosis was 1.6% among treated versus 4.3% among untreated patients. Rates (treated versus untreated) of all-cause inpatient hospitalizations during follow-up were 13.9% versus 22.7% and respiratory-related hospitalizations were 4.2% versus 9.0%. Mean (SD) total all-cause and respiratory-related costs were $9,830 ($18,616.0) and $900 ($4016.4) among the treated, respectively, versus $13,207 ($24,405.1) and $2,024 ($7,623.7) among untreated, respectively. All differences were statistically significant (p < 0.001).

CONCLUSIONS

Lack of antiviral treatment is associated with increased mortality, HCRU, and economic burden in older Medicare beneficiaries with seasonal influenza. Future research should investigate whether the choice of antivirals affects influenza burden.

Antiviral Use and Health Care Use Among US Patients With Rheumatoid Arthritis and Influenza in Three Influenza Seasons, 2016-2019

Objective

Patients with rheumatoid arthritis (RA) are vulnerable to severe complications of influenza. We assessed whether health care resource use (HRU) and costs differed between patients with RA and influenza who received antiviral medication compared with matched patients with RA and influenza not receiving antiviral therapy.

Methods

This was a retrospective US health insurance claims analysis over three influenza seasons (each October to April) in 2016‐2019. Adults with RA and a subsequent diagnosis of influenza were included. Treated patients (receiving antiviral influenza treatment within 2 days of diagnosis) and untreated patients were propensity score matched using baseline covariates. HRU and costs were assessed for inpatient, emergency department (ED), and outpatient visits and compared between cohorts using χ² tests and t tests.

Results

After matching, 2638 treated and 1319 untreated patients were included. For treated versus untreated patients, the mean number of all‐cause outpatient visits was 0.96 versus 1.21 during 14 days of follow‐up (P < 0.001) and 1.94 versus 2.24 over 28 days (P = 0.001), respectively. Over 28 days, the mean number of all‐cause ED visits was lower among treated (0.23) than untreated (0.30) patients (P = 0.042). The mean number of respiratory‐related outpatient visits was significantly lower for treated versus untreated patients, and mean costs for these visits were $17.89 versus $35.27 over 14 days (P < 0.001) and $28.92 versus $48.77 over 28 days (P < 0.001) for treated versus untreated patients, respectively.

Conclusion

Our findings demonstrate that prompt antiviral treatment after influenza diagnosis may reduce HRU and costs in patients with RA.

Risk factors and medical resource utilization in US adults hospitalized with influenza or respiratory syncytial virus in the Hospitalized Acute Respiratory Tract Infection study

Background

Influenza and respiratory syncytial virus (RSV) are associated with substantial morbidity and mortality in the United States. We assessed risk factors for severe disease and medical resource utilization (MRU) among US adults hospitalized with influenza or RSV in the Hospitalized Acute Respiratory Tract Infection (HARTI) study.

Methods

HARTI was a prospective global (40 centers, 12 countries) epidemiological study of adults hospitalized with acute respiratory tract infections conducted across the 2017–2019 epidemic seasons. Patients with confirmed influenza or RSV were followed up to 3 months post‐discharge. Baseline characteristics, prevalence of core risk factors (CRFs) for severe disease (age ≥65 years, chronic heart or renal disease, chronic obstructive pulmonary disease, or asthma), and MRU were summarized descriptively.

Results

The US cohort included 280 influenza‐positive and 120 RSV‐positive patients. RSV patients were older (mean: 63.1 vs. 59.7 years) and a higher proportion had CRFs (87.5% vs. 81.4%). Among those with CRFs (influenza, n = 153; RSV, n = 99), RSV patients required longer hospitalizations (median length of stay: 4.5 days) and a greater proportion (79.8%) required oxygen supplementation during hospitalization compared with influenza patients (4.0 days and 59.5%, respectively). At 3 months post‐discharge, a greater proportion of RSV patients with CRFs reported use of antibiotics, antitussives, bronchodilators, and inhaled and systemic steroids versus those with influenza and CRFs. Many patients with CRFs reported hospital readmission at 3 months post‐discharge (RSV: 13.4%; influenza: 11.9%).

Conclusions

MRU during and post‐hospitalization due to RSV in adults is similar to or greater than that of influenza. Enhanced RSV surveillance and preventive and therapeutic interventions are needed.

Burden of influenza in patients with cardiovascular disease who receive antiviral treatment for influenza

AIMS

Cardiovascular disease (CVD) increases the risk of complications from respiratory viruses, including influenza. Moreover, respiratory viruses may increase the risk of CV events. Antiviral medication may reduce healthcare resource utilization (HRU), but more data is needed in CVD populations to explore relationships between influenza antiviral treatment, CVD-related complications, HRU, and costs.

MATERIALS AND METHODS

This retrospective claims analysis examined data extracted from IBM MarketScan Commercial Claims and Encounters and Medicare Supplemental and Coordination of Benefits databases during three influenza seasons: 2016-2017, 2017-2018, or 2018-2019. Propensity score matching was used to compare HRU outcomes and costs among CVD patients treated with influenza antivirals and untreated patients.

RESULTS

Across all influenza seasons, patients with CVD and influenza who received antiviral treatment had fewer all-cause emergency department (ED) visits (p < .01), respiratory-related HRU (p < .01), respiratory-related outpatient and ED visits (both p < .01), CVD-related HRU (p < .01), heart failure-related HRU visits (p < .01), and kidney failure-related HRU (p < .01) 180 days post-treatment fill date than CVD patients untreated for influenza. CVD patients treated with antivirals also had a lower mean number of all-cause inpatient, outpatient, and ED visits and days of stay (all p < .01) and fewer mean respiratory-related outpatient and ED visits (both p < .01). HRU patterns were generally consistent over time and across individual influenza seasons. Finally, treated CVD patients incurred lower all-cause outpatient costs 180 days post-treatment fill date (p < .05) than CVD patients untreated for influenza.

CONCLUSION

CVD patients who contract influenza and take antiviral medication have fewer short- and long-term influenza-related complications and less overall HRU compared with CVD patients who were not prescribed antiviral treatments. Antiviral treatment may be an important tool in reducing complications in CVD patients with influenza.