Table 4.

Points to consider when evaluating and designing RSV epidemiology studies in adults

Population and case definition
What is the appropriate population for the intended use of the data (all symptomatic patients, primary care/outpatient cases, hospitalized cases)?
Does reporting of incidence/prevalence distinguish between the overall adult population and higher risk groups (older adults, those with comorbidities)?
Is the case definition for screening appropriate for RSV in adults?
Sampling
Does the sampling period capture the full local RSV season?
If only one season is reported, how much variation between seasons is typical in the country in question?
Does the sampling period include the COVID-19 pandemic?
What proportion of eligible sites and/or patients were sampled? Is there potential for under-reporting or sampling bias?
What was the delay between symptom onset and sampling? Could patients have stopped shedding virus by the time of sampling?
Is the sample size adequate? Is the number of RSV cases detected sufficient to support any extrapolations made?
Reporting and adjustment for limitations
If the study relies on single-site sampling (e.g. PCR testing of upper respiratory tract samples), consider applying a multiplier on the basis of published estimates [59, 60] to reflect likely proportion of cases missed
If sampling is not year round, are adjustments made to account for RSV activity outside the sampling period?
Are appropriate measures of uncertainty reported?
Is reporting stratified by age range (specifically older adults age 65+) and/or comorbidity status to allow for assessment of burden in the groups most vulnerable to severe illness from RSV?
In retrospective claim database studies, have adjustments been made to compensate for low rates of RSV testing in clinical practice?
Are study limitations reported and their potential impact on accuracy and generalizability discussed? Have appropriate quantitative adjustments been made to compensate for likely under-reporting and selection bias?