Table 3. Odds ratios (ORs) and 95% confidence intervals (CIs) for ossification of the posterior longitudinal ligament of the spine according to present status of smoking and drinking.

Factors		Crude OR (95% CI)	Adjusted OR (95%CI)
Smoking habit	Current smokers/Never smokers, ex-smokers	1.56 (0.81, 2.81)*1	1.68 (0.78, 3.63)*3
Drinking habit	Once a week and more/ Less than once a week	0.29 (0.15, 0.57)*2	0.35 (0.17, 0.75)*4

Adjusted OR: adjusted for high body mass index (25.0 or greater) and diabetes mellitus.

* The number of cases and controls used for analysis.

*1: 65 cases and 125 controls, *2: 66 cases and 120 controls, *3: 63 cases and 118 controls, *4: 64 cases and 113 controls