3.2.1 Comparison of the baseline characteristics before and
after PSM
Baseline characteristics (age, gender, perforation size, malleus handle
exposure status, and ABG value for frequencies of 250 Hz to 4000 Hz
before surgery) in the TF and FTTC groups were compared; a significant
difference was observed in the ABG values at 2000 Hz. However, after
PSM, the variables in the two groups were balanced. The differences in
the baseline characteristics before and after surgery are shown in
Supplementary Table.