Table 2.

Association of changes in oral condition and behaviour with number of missing teeth over time

Risk factor change	Time-varying number of missing teeth
	Base model*			Adjusted model†
	Beta (95% CI)	RR (95% CI)	P value	Beta (95% CI)	RR (95% CI)	P value
Mean CAL (per 1 mm)	0.10 (0.08 to 0.13)	1.11 (1.09 to 1.14)	<0.001	0.05 (0.03 to 0.07)	1.05 (1.03 to 1.07)	<0.001
Dental plaque index (per 1 point)	0.11 (0.07 to 0.13)	1.11 (1.08 to 1.14)	<0.001	−0.01 (−0.04 to 0.02)	0.99 (0.97 to 1.02)	0.640
Number of decayed and filled teeth (per 1 teeth)	−0.05 (−0.06 to −0.05)	0.95 (0.94 to 0.95)	<0.001	0.04 (0.03 to 0.05)	1.04 (1.03 to 1.04)	<0.001
Toothbrushing ≤1 time (yes)	0.03 (−0.02 to 0.08)	1.03 (0.98 to 1.09)	0.256	−0.02 (−0.06 to 0.02)	0.98 (0.94 to 1.03)	0.424
No regular dental visit (yes)	−0.01 (−0.04 to 0.04)	0.99 (0.96 to 1.04)	0.983	−0.01 (−0.04 to 0.03)	0.99 (0.96 to 1.04)	0.926

Poisson mixed models; time-varying number of missing teeth was the dependent variable and changes in oral condition and behaviour were the independent variable. Rate ratios in number of missing teeth for a one-unit change in the independent variable was calculated using the formula exp (beta), where beta was the parameter estimate for the independent variable from Poisson mixed model.

*Base model; Poisson mixed model adjusted for age and sex.

†Adjusted model included all independent variables (time-varying variables), age, sex, number of present teeth and job at baseline.

CAL, clinical attachment level; RR, rate ratio.