Table 2.

Logistic regression models for the prevalence and incidence of attachment loss (AL) at age 32 (reference category for smoking variables = never smokers)

	Prevalence				Incidence
	1+ sites with 4+ mm AL*		1+ sites with 5+ mm AL†		1+ sites with 3+ mm AL increase‡
	OR	95% CI	OR	95% CI	OR	95% CI
Female§	0.66	0.47, 0.93	0.77	0.48, 1.24	0.85	0.54, 1.32
Low SES at 26	1.17	0.76, 1.80	0.77	0.42, 1.43	1.41	0.84, 2.37
Plaque score at 32¶	1.64	1.19, 2.25	1.21	0.80, 1.83	1.06	0.70, 1.58
Episodic user of dentistry at 26 and 32	1.30	0.91, 1.85	1.71	1.04, 2.82	0.81	0.50, 1.30
Long-term smoker (from age 15 to 32)	5.01	2.97, 8.45	7.13	3.53, 14.38	5.16	2.73, 9.76
Other age-32 smokers	2.75	1.98, 4.20	5.68	3.06, 10.54	3.20	1.83, 5.58
Gave up smoking after age 26	1.59	0.86, 2.95	1.32	0.43, 4.05	1.47	0.62, 3.50
Other ex-smokers	1.50	0.80, 2.79	2.75	1.14, 6.68	1.21	0.48, 3.03

^*Nagelkerke R² = 0.161; Hosmer & Lemeshow test p = 0.771.

^†Nagelkerke R² = 0.182; Hosmer & Lemeshow test p = 0.692.

^‡Nagelkerke R² = 0.087; Hosmer & Lemeshow test p = 0.706.

^§Reference categories: female (male, coded 0), Low SES at 26 (higher SES, coded 0); episodic dental user at 26 and 32 (routine dental visitor, coded 0); smoking exposure variables (never smoker; coded 0).

^¶This is a continuous variable representing the extent of plaque on six index teeth (range 0–3).

CI, confidence interval; OR, odds ratio; SES, socioeconomic status.