(241) Clinical manifestations, complications, and healthcare utilization of adult outpatients with RSV infection in the United States: a retrospective real-word study

Background: The clinical significance and disease burden of respiratory syncytial virus (RSV) remain poorly characterized, particularly among adults under age 60. In addition, most research focuses on the inpatient setting, omitting the significant outpatient population.

Objectives: This study aimed to describe clinical manifestations and complications of RSV infections, and assessed the healthcare resource utilization (HCRU) among adult outpatients with RSV infection in the United States using real-world data.

Methods: This retrospective cohort study used electronic health records from the TriNetX real-world database, including patients diagnosed with RSV in the outpatient setting during flu season from November 1, 2011 to April 30, 2019 in the United States. Patient demographics, clinical presentation and complications were described. HCRU was estimated as the percentage of patients using particular services during the follow-up period (inpatient admissions, emergency department visits, outpatient visits, pharmacy fills), and descriptive statistics were used to summarize and present the results.

Results: A total of 2452 RSV patients were included. Median age was 42 (Interquartile range (IQR) = 20), 1438 patients (58.6%) were female, and 1661 (68.1%) had Charles Comorbidity Index ≥1. Most common symptoms were cough (892 patients, 36.4%), pain (185, 7.6%), headache (174, 7.1%), wheezing (160, 6.5%), crackles (127, 5.2%) and rash (126, 5.1%). 611 patients (24.9%) had ≥1 RSV-related complication, with median time to the complication of 27 days. The most common complications were hypoxia or dyspnea (290, 11.9%), congestive heart failure (162, 6.6%), pneumonia (155, 6.3%), lower and upper respiratory tract infection (122, 5.0%) and acute respiratory infection (98, 4.0%). During 6 months after RSV diagnosis, 1045 patients (42.6%) had ≥1 inpatient admission, with a mean length of stay of 4.1 days. 811 (33.1%) had ≥1 emergency department visit; 221 (9%) had an ICU stay. 2370 (96.7%) patients had ≥1 pharmacy fill and 2047 (83.5%) had ≥1 outpatient visit, with a median visit count of 10 (IQR = 21).

Conclusions: This large, real-world data study found that RSV caused significant burden among US adults under 60 and that RSV-related healthcare utilization was substantial, with the majority of patients receiving follow-up care and almost a quarter exhibiting complications. These results underscore the need to increase the awareness of clinical significance of RSV in adult outpatients, and to accelerate the development of RSV prevention strategies to reduce the healthcare burden across patient populations.