The FDA recently approved the first vaccine to protect against lower respiratory tract disease caused by RSV in adults aged 60 years and older. Pharmacists might be asking what took so long.
According to a study in Infectious Disease and Therapy, one issue is that the burden of RSV in older adults might have been greatly underestimated, at least partly because there are low levels of RSV testing among adults hospitalized for lower respiratory tract infection (LTRI) in the United States.
“Without RSV-specific treatment for adults, testing is uncommon, leading to potential underestimation of RSV incidence in real-world data studies,” according to the researchers who sought to quantify the frequency of RSV testing during LRTI-related hospitalizations of older adults to help interpret incidence estimates.
To do that, the researchers used administrative and billing data for hospitalizations of adults aged 65 years and older with a primary or secondary diagnosis of LRTI during the 2016-2019 RSV seasons (October-April), extracting data from the U.S. all-payer Premier Healthcare Database.
The results indicated that most of the 937 study hospitals performed RSV testing infrequently during LRTI hospitalization. In fact, the median percentage of LRTI hospitalizations with RSV testing was 4.3%, and 78.4% of hospitals performed RSV testing in less than 25% of LRTI-related hospitalizations.
In addition, the researchers added that RSV testing varied by hospital type. Median percentage tested was significantly higher for:
• Hospitals with ≥200 beds (9.1%) versus <200 beds (1.6%)
• Teaching (11.0%) versus nonteaching (2.5%) hospitals
• Urban (7.4%) versus rural (0.7%) settings.
The authors pointed out that the median percentage of RSV testing increased over time—from 0.8% to 6.3% between the 2016/17 and 2018/19 seasons.
Authors of an earlier Department of Veterans Affairs (VA) study agreed, noting, “In adult populations, diagnostic testing for RSV has historically been underutilized.”
That study published in Open Forum Infectious Diseases included 102,251 RSV results, finding that 4,372 (4.3%) specimens from 4,263 unique individuals were positive with a median age of 67 years (range 0-101); most (90%) were male.
Another 1,511 patients (35.4%) also had an RSV-coded hospitalization, although RSV type was specified for only 7.8% of positives.
“During 2010-2018 there were 2,522 RSV-coded hospitalizations (median length of stay = 4 days) among 2,444 unique individuals, which included 413 ICU stays (16.4%) and 98 deaths (3.9%) during the RSV-coded hospitalization,” the researchers pointed out. “Approximately 78% of RSV-coded hospitalizations within VA (excluding all non-VA hospitalizations) had a documented positive test result.”
The study found a greater than 15-fold increase in RSV tests performed, although the percent testing positive remained relatively stable.
In the industry study this year, the authors pointed out, “RSV infection in elderly patients can lead to severe LRTI, hospitalization, and potential progression to critical conditions such as respiratory failure or death. Despite potential threats, RSV testing in elderly inpatients is infrequent, likely due to current treatment options being supportive only, with no RSV-specific treatments in use. Low testing rates can result in underestimation of RSV incidence, particularly in real-world data studies relying on pathogen-specific ICD [International Classification of Diseases], which will not be assigned without a standard-of-care RSV test.”
The content contained in this article is for informational purposes only. The content is not intended to be a substitute for professional advice. Reliance on any information provided in this article is solely at your own risk.
« Click here to return to Vaccine Update.
