*P<0.05, **P<0.01, ***P<0.001

Abbreviations: 95% confidence interval (95% CI), interquartile range (IQR), SD (standard deviation), and NA (not available)

^† The percentage of allergists and clinical immunologists receiving payments were estimated using the workforce report issued by the Association of American Medical Colleges in 2015, 2017, and 2019. The number of active allergists and clinical immunologists in 2016, in 2018, and 2020 were not available from the workforce reports.