Table 3.

Effect size of association, differences in prevalence and description of strength of association

			Association		Prevalence of tooth loss (%)
Type of exposure	First author, year	Sex	Effect size (95% CI)	Type	Current smoker	Non-smoker	Difference	Strength of association
Current smokers	Randolph, 2001	M F	1.69 (1.31, 2.20)	OR	50 57	41 46	9 11	Moderate Moderate
	Klein, 2004	M, F	4.04 (2.52, 6.49)	OR	92.3	79.5	12.8	Moderate
	Musacchio, 2007	M, F	4.01 (2.59, 6.20)	OR	48.1**	42.3**	5.8**	Weak
	Ojima, 2007	M F	2.21 (1.40, 3.50) 1.70 (1.13, 2.55)	OR	39.3 43.2	21.8 29.4	17.5 13.8	Moderate Moderate
	Hanioka, 2007	M F	2.24 (1.28, 3.94) 2.74 (1.46, 5.16)	OR	36.9 38.9	28.5 38.6	8.4 0.3	Moderate Weak
	Mundt, 2007	M, F	2.3 (1.6, 3.4)*	OR	21.1**	8.4**	12.7**	Moderate
	Krall, 2006	M	2.1 (1.5, 3.1)	HR				Weak
	Dietrich, 2007	M	2.3 (2.1, 2.5)*	HR				Moderate
Former smokers	Randolph, 2001	M F	1.26 (1.04, 1.54)	OR	45 55	41 46	4 9	Weak*** Moderate
	Klein, 2004	M, F	1.57 (1.25, 1.98)	OR	85.8	79.5	6.3	Weak***
	Musacchio, 2007	M, F	3.42 (2.42, 4.82)	OR	45.5**	42.3**	3.2**	Weak
	Ojima, 2007	M F	1.25 (0.55, 2.86) 0.52 (0.23, 1.18)	OR	26.3 20.0	21.8 29.4	4.5 -9.4	NS***
	Hanioka, 2007	M F	1.55 (0.88, 2.74) 1.17 (0.44, 3.09)	OR	38.6 34.3	28.5 38.6	10.1 -4.3	NS***
	Mundt, 2007	M, F	1.7 (1.0, 3.1)*	OR	12.1**	8.4**	3.7**	NS***
	Krall, 2006	M	1.3 (0.9, 1.7)	HR				NS***
	Dietrich, 2007	M	1.2 (1.2, 1.3)*	HR				Weak***

The evidence of weak to moderate association between smoking and tooth loss was consistent in high-quality studies, and the effect size was consistently smaller for former smokers than for current smokers.

CI, confidence interval; OR, odds ratio; HR, hazard ratio; *extracted from the category that included the median value of the group as a representative because the effect size for all current or all former smokers was not reported; **calculated by reviewer based on date in the table in the original literature; ***lower rank than current smokers