BACKGROUND: Despite underdiagnosis in routine care, re-spiratory syncytial virus (RSV) is a common cause of acute respiratory illness (ARI) in older adults and adults with chronic conditions who are at increased risk of severe out-comes of RSV.
OBJECTIVE: To describe the clinical and economic burden of hospitalized cases of diagnosed RSV in adults aged at least 50 years with chronic conditions.
METHODS: This retrospective cohort study identified pa-tients aged at least 50 years in an administrative claims database including members with commercial insurance or Medicare Advantage with Part D. Among adults with chron-ic conditions, diagnosed RSV cases were identified from July 2016 to June 2020 using International Classification of Dis-eases, Tenth Revision, Clinical Modification diagnosis codes. Control patients (without RSV) were identified during this period and matched to RSV cases based on their clinical, de-mographic, and health care utilization characteristics. For RSV cases, matching characteristics were measured dur-ing the 12 months before their first ARI diagnosis within the RSV episode (the index date); for controls, characteristics were measured during a corresponding 12-month baseline period. Total costs and total cost differences for matched cohorts of RSV cases vs controls were assessed as well as hospital discharge status and 30-day mortality for hospital-ized RSV cases.
RESULTS: The matched cohorts included 10,639 diagnosed RSV cases and 36,151 control patients. Patients with diag-nosed RSV cases had a mean (SD) age of 75.6 (9.7) years and a mean (SD) Charlson Comorbidity Index score of 5.1 (4.0); baseline characteristics were similar in matched controls. Most diagnosed RSV cases (69.5%) were hospitalized. Dur-ing the period of 7 days before to 30 days after the index date, mean (SD) total costs were $42,719 ($55,628) and $7,317 ($26,249) for diagnosed RSV cases with a hospitalization and matched controls, respectively, with a difference of $34,282 (paired t-test P < 0.01). For the subset of hospitalized RSV cases in adults aged 50-59 years, this cost difference was $31,811. Among hospitalized RSV cases, 48.4% were dis-charged home, another 21.2% were discharged home with home health follow up, 4.8% were discharged to hospice, and 4.3% were discharged to a skilled nursing facility. All-cause 30-day mortality was 8.1% for hospitalized RSV cases.
CONCLUSIONS: Among adults with chronic conditions, hos-pitalized RSV episodes were associated with substantial clinical and economic burden, including risk of mortality. Although results were limited to patients with diagnosed RSV, findings show the importance of RSV prevention in these patients
