Temporal Trends and Geographic Variations in Dementia Mortality in China Between 2006 and 2012: Multilevel Evidence From a Nationally Representative Sample

Abstract

Objectives: We aimed to explore the temporal trends and geographic variations in dementia mortality in China.

Materials and methods: Annual dementia mortality counts (years 2006 to 2012) in 161 counties and districts (Disease Surveillance Points, DSP) were extracted from the nationally representative China Mortality Surveillance System and stratified by 5-year age group (aged >65), sex, and time. These counts were linked to annually adjusted denominator populations. Multilevel negative binomial regression with random intercepts and slopes were used to investigate spatiotemporal variation in dementia mortality.

Results: Dementia mortality varied over 2-fold between DSPs (median rate ratio: 2.59). Significant variation in DSP slopes through time (variance 0.075, SE 0.020) indicated spatiotemporal variations. Mortality rates were significantly higher in the east (rate ratio 2.28; 95% confidence intervals, 1.45-3.60) compared with the north. There was a declining trend in 2 (east and northwest) of the 7 regions. Dementia mortality decreased by 15% in urban areas but increased by 24% in rural areas.

Conclusions: Our findings indicate that regional inequalities in dementia mortality are salient, and the increase in mortality rates in rural areas is an emerging public health challenge in China. Tailored preventive health strategies should be in place to narrow down this avoidable and wholly unnecessary inequality.