OBJECTIVES: Although some studies have reported the cost of medically-attended respiratory syncytial virus (RSV) among adults during the acute phase of illness, few studies have reported attributable costs of adult RSV thereafter. We sought to estimate the attributable costs of RSV during and up to 1 year after acute, medically attended illness.

METHODS: We used a retrospective observational matched-cohort design and data from a large US healthcare claims repository (MarketScan Commercial/Medicare Databases, 2016-2019). The study population included patients with evidence of RSV (based on corresponding diagnosis codes) requiring hospitalization (“hospitalized-RSV”), an emergency department visit (“ED-RSV”), or physician office/hospital outpatient visit (“PO/HO-RSV”), and matched comparison patients. RSV and comparison patients were matched (1:1, without replacement) on a rolling (monthly) basis based on age, sex, health plan type, comorbidity profile, and markers of healthcare burden during the 1-year history period. All-cause expenditures (2020US$) were tallied during the acute phase of illness (hospitalized-RSV: from date of admission through 30 days post-discharge; ambulatory RSV: during the episode, defined as date of first evidence through date of last evidence [<90 days apart]) and the long-term phase (end of acute phase to end of following 1-year period).

RESULTS: Study population included 2,695 matched pairs of RSV/comparison patients (hospitalized-RSV: N=297; ED-RSV: N=112; PO/HO-RSV: N=2,286). Mean expenditures during the acute phase of illness were $38,550 for hospitalized-RSV (vs. $3,212 for comparison patients), $2,093 for ED-RSV (vs. $16), and $761 for PO/HO-RSV (vs. $96). By the end of the 1-year follow-up period, mean all-cause expenditures (acute plus long-term phases) were $70,019 for hospitalized-RSV (vs. $28,011), $14,866 for ED-RSV (vs. $1,108), and $14,466 for PO/HO-RSV (vs. $1,830); RSV-attributable expenditures thus totaled $42,009, $13,758, and $12,636, respectively.

CONCLUSIONS: The cost of RSV requiring hospitalization or ambulatory care in the U.S. is substantial. The economic impact of RSV illness extends beyond the acute phase of illness.