Table 2.

Associations between tinnitus with risk of Alzheimer’s disease and Parkinson’s disease.

	Alzheimer’s disease		Parkinson’s disease
	HR (95% CI)	P value	HR (95% CI)	P value
Model I	1.62 (1.41–1.85)	< 0.001	1.69 (1.41–2.04)	< 0.001
Model II	1.54 (1.34–1.78)	< 0.001	1.56 (1.29–1.89)	< 0.001
Model III	1.34 (1.17–1.53)	< 0.001	1.44 (1.19–1.73)	< 0.001

Model I: univariate analysis.

Model II: included univariate analysis factors with a moderate statistically significant relationship (i.e., P <  0.1) into a multivariate Cox proportional-hazards regression model by using the forward selection method.

Model III: included all variates.