Trends in Respiratory Pathogen Testing at US Children's Hospitals

Abstract

Importance: Respiratory pathogen testing has been a common deimplementation focus. The COVID-19 pandemic brought new considerations for respiratory testing; recent trends in testing rates are not well understood.

Objective: To measure trends in respiratory testing among encounters for acute respiratory infections among children and adolescents (aged <18 years) from 2016 to 2023, assess the association of COVID-19 with these trends, and describe associated cost trends.

Design, setting, and participants: This retrospective serial cross-sectional study included emergency department (ED) encounters and hospitalizations in US children's hospitals among children and adolescents with a primary acute infectious respiratory illness diagnosis. Data were ascertained from the Pediatric Health Information System database from January 1, 2016, to December 31, 2023.

Exposure: Respiratory pathogen testing.

Main outcomes and measures: The primary outcome was the percentage of encounters with respiratory testing over time. Interrupted time series models were created to assess the association of COVID-19 with testing patterns. The inflation-adjusted standardized unit cost associated with respiratory testing was also examined.

Results: There were 5 090 923 eligible encounters among patients who were children or adolescents (mean [SD] age, 3.36 [4.06] years); 55.0% of the patients were male. Among these encounters, 87.5% were ED only, 77.9% involved children younger than 6 years, and 94.5% involved children without complex chronic conditions. Respiratory testing was performed in 37.2% of all encounters. The interrupted time series models demonstrated increasing prepandemic testing rates in both ED-only encounters (slope, 0.26 [95% CI, 0.21-0.30]; P < .001) and hospitalizations (slope, 0.12 [95% CI, 0.07-0.16]; P < .001). Increases in respiratory testing were seen at the onset of the COVID-19 pandemic in both ED-only encounters (level change, 33.78 [95% CI, 31.77-35.79]; P < .001) and hospitalizations (level change, 30.97 [95% CI, 29.21-32.73]; P < .001), associated initially with COVID-19-only testing. Postpandemic testing rates remained elevated relative to prepandemic levels. The percentage of encounters with respiratory testing increased from 13.6% [95% CI, 13.5%-13.7%] in 2016 to a peak of 62.2% [95% CI, 62.1%-62.3%] in 2022. While COVID-19-only testing decreased after 2020, other targeted testing and large-panel (>5 targets) testing increased. The inflation-adjusted standardized unit cost associated with respiratory testing increased from $34.2 [95% CI, $33.9-$34.6] per encounter in 2017 to $128.2 [95% CI, $127.7-$128.6] per encounter in 2022.

Conclusions and relevance: The findings of this cross-sectional study suggest that respiratory testing rates have increased over time, with large increases at the onset of the COVID-19 pandemic that have persisted. Respiratory testing rates and related costs increased significantly, supporting a need for future deimplementation efforts.

Figure 1.. Unadjusted Percentage of Encounters With Any Respiratory Pathogen Testing, 2016-2023

ED indicates emergency department; ICU, intensive care unit; Q, quarter.

Figure 2.. Time Series of Unadjusted Percentage of Encounters With Categories of Respiratory Pathogen Testing, 2016-2023

Targeted respiratory testing is 5 or fewer targets; large-panel respiratory testing is more than 5 targets. ED indicates emergency department; ICU, intensive care unit; Q, quarter.

Figure 3.. Interrupted Time Series Model Analysis of Adjusted Percentage of Encounters With Respiratory Pathogen Testing

The onset of the COVID-19 pandemic in March 2020 (dashed vertical line) defines the segments before and after COVID-19; the months of March and April 2020 were censored. A, Model for emergency department (ED)-only encounters adjusting for hospital, seasonality, age, and number of complex chronic conditions. Prepandemic slope: 0.26 (95% CI, 0.21-0.30); level change at COVID-19 onset: 33.78 (95% CI, 31.77-35.79); and change in slope from before to after the pandemic: −0.32 (95% CI, −0.39 to −0.24) (P < .001). B, Model for hospitalizations adjusting for hospital, seasonality, age, number of complex chronic conditions, and hospitalization resource intensity scores for kids. Prepandemic slope: 0.12 (95% CI, 0.07-0.16); level change at COVID-19 onset: 30.97 (95% CI, 29.21-32.73); and change in slope from before to after the pandemic: −0.34 (95% CI, −0.40 to −0.28) (P < .001). The orange dashed line indicates the slope of respiratory pathogen testing before the onset of the COVID-19 pandemic; the orange dotted line is a counterfactual trend line (extrapolation of the prepandemic slope). The light blue solid line indicates the slope of respiratory pathogen testing after the onset of the COVID-19 pandemic. The solid black line indicates the adjusted percentage of respiratory tests received.