Matthews Fiona, Brayne Carol
MRC Biostatistics Unit, Institute of Public Health, University Forvie Site, Robinson Way, Cambridge, United Kingdom.
PLoS Med. 2005 Aug;2(8):e193. doi: 10.1371/journal.pmed.0020193. Epub 2005 Aug 23.
Although incidence of dementia is known to vary between nations, variation within country has not been explored because most incidence studies are single site or have insufficient numbers to compare sites. Few countries have conducted multisite incidence studies in order to facilitate national comparisons. This study aims to provide robust measures of the variation of the incidence of dementia across sites within England and Wales and produce overall estimates by age and sex.
The Medical Research Council Cognitive Function and Ageing Study used identical methodology in five diverse sites across the United Kingdom, each with different risk patterns and mortality rates. Incidence has been estimated using likelihood-based methods between the first two waves of interviews. Incidence rates rise with age, particularly above the age of 75 y, from 6.7 [corrected] (95% confidence interval, 3.8 [corrected]-12.4 [corrected]) per 1,000 person years at age 65-69 y to 68.5 [corrected] (95% confidence interval, 52.5 [corrected]-88.1 [corrected]) per 1,000 person years at age 85 y and above. The rate of increase for both sexes is marked, and continues into the oldest age groups. Hence, it is estimated that approximately 163,000 [corrected] new cases of dementia occur in England and Wales each year. There is no convincing evidence of variation across sites, and incidence rates do not reflect the variations in the prevalence of possible risk factors in these sites.
There is no evidence, within England and Wales, of variation in dementia incidence across sites. Dementia incidence rates do not tail off at the oldest ages.
虽然已知痴呆症发病率在不同国家之间存在差异，但国内差异尚未得到探究，因为大多数发病率研究都是单中心的，或者样本数量不足以进行不同地点之间的比较。很少有国家开展多中心发病率研究以方便进行全国性比较。本研究旨在提供关于英格兰和威尔士境内不同地点痴呆症发病率差异的可靠衡量指标，并按年龄和性别得出总体估计值。
医学研究理事会认知功能与衰老研究在英国五个不同地点采用了相同的方法，每个地点具有不同的风险模式和死亡率。发病率通过两轮访谈之间基于似然性的方法进行估计。发病率随年龄增长而上升，尤其是在75岁以上，从65 - 69岁时每1000人年6.7[校正后]（95%置信区间，3.8[校正后] - 12.4[校正后]）升至85岁及以上时每1000人年68.5[校正后]（95%置信区间，52.5[校正后] - 88.1[校正后]）。两性的增长速度都很显著，且在最高年龄组中仍持续。因此，据估计英格兰和威尔士每年约有163,000[校正后]例新发痴呆症病例。没有令人信服的证据表明不同地点之间存在差异，发病率也未反映这些地点潜在风险因素患病率的差异。
在英格兰和威尔士，没有证据表明不同地点之间痴呆症发病率存在差异。痴呆症发病率在最高年龄时并未下降。
