Table 2. Associations of tooth loss with general and oral health status (univariate analysis).

Variables			Tooth loss (n=1)			Tooth loss (n=2–3)			Tooth loss (n≥4)
			HR	95% CI	P value	HR	95% CI	P value	HR	95% CI	P value
Sex (Ref: male)
	Female		0.77	0.77–0.78	<0.001	0.72	0.71–0.73	<0.001	0.66	0.75–0.21	<0.001
Age group (Ref: 40–49 years)
	50–59		1.52	1.50–1.55	<0.001	1.72	1.69–1.75	<0.001	1.95	1.90–2.00	<0.001
	60–69		1.79	1.77–1.82	<0.001	2.22	2.17–2.26	<0.001	2.79	2.72–2.87	<0.001
	70–79		1.46	1.43–1.50	<0.001	1.93	1.88–1.98	<0.001	2.62	2.52–2.72	<0.001
Household income (Ref: first quintile)
	Second quintile		1.00	0.98–1.02	0.715	0.99	0.97–1.02	0.627	1.00	0.96–1.03	<0.001
	Third quintile		1.02	1.00–1.04	0.108	1.01	0.98–1.04	0.463	1.00	0.96–1.03	<0.001
	Fourth quintile		0.96	0.95–0.98	<0.001	0.94	0.92–0.96	<0.001	0.92	0.89–0.95	<0.001
	Fifth quintile		0.86	0.85–0.88	<0.001	0.81	0.79–0.83	<0.001	0.74	0.72–0.76	<0.001
Insurance status (Ref: NHIS [Employees])
	Self-employed		1.06	1.05–1.07	<0.001	1.10	1.08–1.12	<0.001	1.15	1.13–1.18	<0.001
Presence of disability (Ref: none)
	Present		1.14	1.06–1.23	<0.001	1.29	1.18–1.41	<0.001	1.44	1.28–1.61	<0.001
BMI (kg/m2) (Ref: normal)
	<18.5 (Underweight)		0.96	0.93–1.00	0.068	1.02	0.98–1.08	0.331	1.16	1.08–1.23	<0.001
	23–25 (Overweight)		1.10	1.09–1.12	<0.001	1.09	1.07–1.11	<0.001	1.05	1.02–1.08	<0.001
	≥25 (Obese)		1.23	1.21–1.24	<0.001	1.23	1.21–1.26	<0.001	1.19	1.16–1.22	<0.001
Smoking status (Ref: non/former smoker)
	Current smoker		1.37	1.36–1.39	<0.001	1.50	1.48–1.52	<0.001	1.67	1.64–1.70	<0.001
Drinking status (Ref: none)
	<3 times/week		1.06	1.05–1.07	<0.001	1.05	1.03–1.06	<0.001	1.02	1.00–1.04	0.0886
	≥3 times/week		1.28	1.25–1.30	<0.001	1.36	1.33–1.39	<0.001	1.43	1.39–1.47	<0.001
Periodic dental visits (Ref: yes)
	No		0.76	0.75–0.76	<0.001	0.72	0.72–0.73	<0.001	0.70	0.68–0.71	<0.001
Periodic scaling (Ref: yes)
	No		0.92	0.90–0.93	<0.001	0.91	0.90–0.92	<0.001	0.93	0.90–0.95	<0.001
Brushing before sleep (Ref: yes)
	No		1.08	1.07–1.10	<0.001	1.13	1.11–0.14	<0.001	1.19	1.16–1.21	<0.001
Comorbid disease (Ref: normal)
	Hypertension		1.20	1.18–1.22	<0.001	1.25	1.22–1.27	<0.001	1.29	1.25–1.32	<0.001
	Diabetes mellitus		1.42	1.39–1.45	<0.001	1.58	1.55–1.63	<0.001	1.80	1.74–1.86	<0.001
	CCI score (Ref: 0)
		1	1.04	1.03–1.05	<0.001	1.04	1.03–1.06	<0.001	1.05	1.03–1.08	<0.001
		≥2	1.07	1.05–1.09	<0.001	1.11	1.08–1.13	<0.001	1.15	1.11–1.19	<0.001

Boldface denotes statistical significance (P<0.05).

HR: hazard ratio, CI: confidence interval, BMI: body mass index, CCI: Charlson comorbidity index.