Table 1: Characteristics of patients in frequent and infrequent double lumen tube user groups.

Frequent ( 𝑛 = 7 9 0 )Infrequent ( 𝑛 = 9 9 ) 𝑃

Age (years ± SD)62 ± 1449 ± 21<0.001
Sex (M/F)442/34966/33<0.05
ASA PS (1/2/3/4)13/408/346/2415/41/36/7<0.005

Values for continuous data are reported as mean ± standard deviation and compared by 𝑡 testing. Categorical data were compared by 𝑋 2 analysis. Age is reported as mean ± standard deviation. ASA physical status is reported as the number of patients in each category.
ASA PS: American Society of Anesthesiologists physical status classification.