Table 3.

Results of the meta-analysis.

Overall and subgroup analysis	No. of studies	Meta-analysis		Effect model	Heterogeneity test
		RR (95%CI)	P-value		I2(%)	P-value within group	P-value between group
Overall	11	1.34(1.19–1.51)	0.00	Fixed	36.3	0.11	–
STUDY DESIGN
Prospective cohort	7	1.43(1.23–1.66)	0.00	Fixed	34.4	0.17	0.16
Retrospective cohort	4	1.20(0.99–1.45)	0.07	Fixed	33.7	0.21	–
STUDY AREA
Asia	4	1.33(0.99–1.77)	0.06	Fixed	24.6	0.26	0.20
America	3	1.16(0.95–1.42)	0.14	Fixed	44.8	0.16	–
Europe	4	1.48(1.25–1.74)	0.00	Fixed	36.3	0.18	–
FOLLOW-UP TIME
<10	5	1.44(1.23–1.55)	0.00	Fixed	8.7	0.36	0.17
≥10	6	1.36(1.01–1.83)	0.046	Random	47.1	0.09	–
DENTURE STATUS
With denture	4	0.98(0.87–1.10)	0.74	Fixed	<0.01	0.93	<0.01
Without denture	4	1.53(1.19–1.97)	0.00	Fixed	14.7	0.32	–
RISK EXPRESSION
HR	4	1.27(1.04–1.46)	0.02	Random	47.9	0.08	0.06
OR	7	1.90(1.29–2. 80)	0.00	Fixed	<0.01	0.88	–
ADJUSTMENT STRENGTH
Weak	6	1.56(1.03–2.36)	0.04	Random	50.5	0.07	0.88
Strong	5	1.33(1.17–1.53)	0.00	Fixed	28.2	0.23	–
ADJUSTMENT FOR SMOKING
Yes	4	1.32(1.19–1.51)	0.00	Fixed	40.1	0.17	0.62
No	7	1.41(1.11–1.79)	0.01	Fixed	42.5	1.11	–
ADJUSTMENT FOR ALCOHOL
Yes	5	1.29(1.14–1.46)	0.00	Fixed	40.7	0.15	0.11
No	6	1.69(1.24–2.41)	0.00	Fixed	22.3	0.27	–
ADJUSTMENT FOR EDUCATION
Yes	6	1.36(1.19–1.54)	0.00	Fixed	32.9	0.19	0.64
No	5	1.45(0.92–2.29)	0.11	Random	50.2	0.09	–
ADJUSTMENT FOR CCD
Yes	8	1.25(1.05–1.48)	0.01	Fixed	31.0	0.18	0.28
No	3	1.40(1.00–1.63)	0.047	Random	54.4	0.11	–

RR, relative risk; CI, confidence interval; HR, hazard ratio; OR, odds ratio; CCD, Cardiovascular and cerebrovascular diseases.