Table 3. Comparison of follow-up duration and clinical changes between the surgical treatment and untreated groups

Variables	Surgical treatment group (n=31)	Untreated group (n=43)	p-value†
Time between PSGs (month)	40.4±45.6	38.6±36.4	0.852
ΔAHI between PSGs (/hr)	–7.1±36.9	0.5±24.5	0.324
ΔBMI between PSGs (kg/m2)	0.52±1.75	–0.32±2.29	0.076
ΔESS between PSGs	–3.2±5.2	–0.4±4.1	0.011*
ΔPSQI between PSGs	–0.9±2.5	–1.0±2.9	0.876

p<0.05.
p-value was calculated by independent t-test comparing the surgical treatment and untreated groups.
Δ (Delta) indicates the value of 2nd PSG minus 1st PSG.
PSG: polysomnography, BMI: body mass index, AHI: apnea-hypopnea index, ESS: Epworth sleepiness scale, PSQI: Pittsburgh sleep quality index.