Table 3.

Stratification analysis of depression risk in tonsillectomy patients

	Cases occurring new-onset depression
Subgroups	Tonsillectomy cohort (No. of event/ Tonsillectomy patient amount in each subgroup)	Control cohort (No. of event/ non-Tonsillectomy patient amount in each subgroup)	HR (95% CI)a
Gender
Male	244/4792	194/4792	1.30 (1.08,1.57)
Female	1059/10,008	873/10,008	1.30 (1.18,1.42)
Age at index date
18-64 years old	1296/14,645	994/14,645	1.37 (1.26,1.49)
≥ 65 years old	19/226	19/226	0.96 (0.51,1.82)

^a Propensity score matching was performed on age at index, sex, race, body mass index, status of comorbidities (including diabetes mellitus, hypertension, hyperlipidemia), status of comedication use (antidepressants, corticosteroids), status of smoking, alcoholism and substance use, medical utilization status (inpatient, ambulatory), lab data (CRP)