Accurate estimation of respiratory syncytial virus (RSV) incidence in lower respiratory tract infections (LRTI)-related hospitalizations is crucial for understanding the clinical and economic burden of the disease, particularly among older adults (≥65 years).

We used the comprehensive all-payer Premier Healthcare Database (PHD) to quantify the frequency of RSV testing in US hospitals and to inform the interpretation of incidence estimates.

Among 937 study hospitals, 78.4% performed RSV testing in less than 25% of LRTI-related hospitalizations, and the median percentage of LRTI hospitalizations with RSV testing was 4.3%.

Our findings imply that relying on retrospective database analyses can result in a substantial underestimation of the true RSV incidence as a consequence of limited testing. RSV incidence studies using such data should adjust their interpretations accordingly.