Gender and Age Differences and the Trend in the Incidence and Prevalence of Dementia and Alzheimer’s Disease in Taiwan: A 7-Year National Population-Based Study

Table 4

Multivariate Poisson regression model on the incidence and prevalence rates of dementia in Taiwan from 2004–2010.

Variables	Incidence rates				Prevalence rates
	Crude IRR	95% CI	Adjusted IRR	95% CI	Crude PRR	95% CI	Adjusted PRR	95% CI
Year (ref. = 2004)
2005	0.99	0.98–1.01	0.98	0.96–1.00	1.14	1.13–1.15	1.12	1.11–1.13
2006	1.03	1.01–1.05	1.01	0.99–1.02	1.29	1.28–1.30	1.24	1.23–1.25
2007	1.05	1.03–1.07	1.02	0.98–1.02	1.43	1.42–1.43	1.35	1.34–1.36
2008	1.04	1.02–1.06	1.00	1.00–1.03	1.56	1.55–1.57	1.45	1.44–1.46
2009	1.06	1.04–1.08	1.01	0.99–1.02	1.69	1.68–1.70	1.55	1.54–1.56
2010	1.05	1.04–1.07	0.98	0.97–1.00	1.82	1.81–1.84	1.63	1.61–1.64
Trend test	β = 0.0105,		β = −0.0012,		β = 0.0972,		β = 0.0784,
Age (ref. = 65–69)
70–74	2.01	1.98–2.05	2.01	1.98–2.05	1.99	1.97–2.20	1.98	1.97–2.00
75–79	3.55	3.50–3.61	3.58	3.52–3.64	3.69	3.66–3.71	3.71	3.68–3.73
80–84	5.46	5.37–5.55	5.51	5.42–5.60	6.14	6.09–6.18	6.08	6.04–6.12
≥85	7.58	7.45–7.71	7.58	7.45–7.71	10.88	10.81–10.96	10.64	10.56–10.71
Trend test	β = 0.4907,		β = 0.4913,		β = 0.5799,		β = 0.5732,
Sex (ref. = male)
Female	1.11	1.10–1.12	1.15	1.14–1.16	1.10	1.09–1.11	1.11	1.09–1.12

IRR, incidence rate ratio; PRR, prevalence rate ratio; CI, confidence interval; Ref., reference. .