Table 1. Dementia incidence rates by key variables.

Variable	Value	Person-years (PY)	Cases	IR	LCI	UCI
Hearing impairment	no	365,464	7035	1.92	1.88	1.97
	unilateral	10,617	153	1.44	1.23	1.69
	bilateral	91,421	3238	3.54	3.42	3.67
	unspecified	93,959	2205	2.35	2.25	2.45
	other diseases of the ear	108,064	1971	1.82	1.75	1.91
Treatment by an ENT doctor	no	444,605	9371	2.11	2.07	2.15
	yes	224,919	5231	2.33	2.26	2.39
Care level	no care level	614,887	7208	1.17	1.15	1.20
	1	35,396	4021	11.36	11.01	11.72
	2	16,279	2739	16.83	16.21	17.47
	3	2962	634	21.41	19.80	23.14
Nursing home	no	659,308	11,901	1.81	1.77	1.84
	yes	10,216	2701	26.44	25.46	27.46
Depression	no	508,545	9174	1.80	1.77	1.84
	yes	160,979	5428	3.37	3.28	3.46
Total		669,524	14,602	2.18	2.15	2.22

Data source: Claims data AOK 2006–2010;

IR: Incidence rate per 100 PY

LCI: 95% lover confidence interval

UCI: 95% upper confidence interval

Dementia incidence rates for covariates presented in S1 Table