Table 2. Hazard ratios (HRs) for mortality from pneumonia by number of teeth lost.

Number of teeth lost (excluding third molars)	n	Person-years	Death from pneumonia	Age- and sex-adjusted		Multivariable-adjusteda
				HR	95% CIb	HR	95% CIb
0–14	18,532	177,988	26	1.00		1.00
15–27	741	6,301	17	1.56	0.81–2.99	1.60	0.83–3.10
28	502	4,089	25	2.08	1.10–3.92	2.07	1.09–3.95
				Trend p = 0.024c		Trend p = 0.026c
0–9	18,098	174,089	18	1.00		1.00
10–19	739	6,528	15	2.61	1.28–5.32	2.68	1.31–5.51
> 20	938	7,762	35	2.38	1.23–4.60	2.39	1.22–4.67
				Trend p = 0.012c		Trend p = 0.015c
Per tooth	19,775	188,378	68	1.031	1.005–1.059	1.031	1.004–1.060
				p = 0.021		p = 0.025

^aAdjusted for age (as a continuous variable), sex, smoking (never, former, or current smokers), medical history of diabetes (yes or no), body mass index (< 18.5, 18.5–24.9 or > 25.0 kg/m²) and vigorous physical activity (< 30 minutes/week or > 30 minutes/week). Missing covariate values were incorporated into proportional hazard models as additional categories.

^bConfidence interval.

^cIncreasing trend in the risk of mortality from pneumonia with an increasing number of teeth lost was statistically tested by assigning a score of 0, 1 or 2 to either the loss of 0–14, 15–27 or 28 teeth or the loss of 0–9, 10–19, or 20–28 teeth in the proportional hazard models.