Table 3.

Results of Cox proportional hazards models examining the effect of depressive symptoms (trichotimized groups) on risk of incident aMCI.

	Women			Men
Parameter	Hazard Ratio (95% CI)	Standard Error	p-value	Hazard Ratio (95% CI)	Standard Error	p-value
Model 1 – Unadjusted depressive symptoms
Overall depressive symptoms	–	–	0.05	–	–	0.04
Mild vs. no/low depressive symptoms	1.38 (0.85–2.25)	0.25	0.19	2.33 (1.33–4.08)	0.29	0.003
Moderate/severe vs. no/low depressive symptoms	2.10 (1.12–3.94)	0.32	0.02	0.27 (0.04–1.96)	1.01	0.20
Model 2 – Adjust for demographics
Age	1.08 (1.04–1.12)	0.02	<0.001	1.09 (1.04–1.14)	0.02	<0.001
Education (years)	0.90 (0.85–0.96)	0.03	0.002	1.04 (0.97–1.11)	0.04	0.32
Overall depressive symptoms	–	–	0.10	–	–	0.004
Mild vs. no/low depressive symptoms	1.25 (0.77–2.05)	0.25	0.37	2.32 (1.32–4.08)	0.29	0.003
Moderate/severe vs. no/low depressive symptoms	1.97 (1.05–3.70)	0.32	0.03	0.28 (0.04–2.04)	1.01	0.21
Model 3 – Adjust for significant covariates
Age	1.08 (1.04–1.12)	0.02	<0.001	1.10 (1.05–1.15)	0.02	<0.001
Education (years)	0.90 (0.85–0.96)	0.03	0.002	1.03 (0.96–1.11)	0.04	0.38
Antidepressant medication use	0.89 (0.28–2.87)	0.59	0.84	3.28 (1.27–8.49)	0.48	0.01
Overall depressive symptoms	–	–	0.10	–	–	0.007
Mild vs. no/low depressive symptoms	1.26 (0.77–2.06)	0.25	0.36	2.22 (1.26–3.89)	0.29	0.006
Moderate/severe vs. no/low depressive symptoms	1.99 (1.05–3.77)	0.33	0.03	0.29 (0.04–2.11)	1.01	0.22

Notes. Cox proportional hazards models estimated hazard ratios (HR) and 95% confidence intervals (CIs) with 2 degree of freedom for the main effect of the overall depressive symptom variable and 1 degree of freedom for the individual contrasts of depressive symptom groups and covariates. The Wald Chi-square test was the test statistic used to determine significance level of parameters in the Cox models.