Table 2.

Associations between frequency of playing card/mahjong and dementia for Chinese older adults.

Frequency of playing card/mahjong	N cases/N total	ID (95%CI) per 1,000 persons-years	Unadjusted model HR(95% CI)	P value	Age-and sex-adjusted model HR(95% CI)	P value	Multivariable-adjusted model HR (95% CI)	P value
Rarely or never	744/10,280	16.4 (15.3–17.6)		Ref		Ref		Ref
Sometimes, at least once for a month	32/579	8.8 (6.2–12.4)	0.52 (0.36–0.73)	0.002	0.77 (0.54–1.10)	0.139	0.84 (0.59–1.21)	0.146
Regularly, at least	21/405	8.2 (5.4–12.5)	0.47 (0.31–0.74)	<0.001	0.66 (0.42–1.02)	0.087	0.75 (0.50–1.16)	0.134
once for a week
almost everyday	24/557	6.7 (4.5–9.9)	0.38 (0.25–0.57)	<0.001	0.55 (0.36–0.82)	0.016	0.63 (0.42–0.95)	0.031

ID, Incidence density; HR, hazard ratio; CI, Confidence interval. Multivariable-adjusted model including age, sex, education, household income, marital status, smoking status, drinking status, exercise, BMI, living with family members, hypertension, diabetes, and MMSE score.