Saskatchewan Health Quality Council, Saskatoon, Saskatchewan, Canada.
Department of Psychiatry and School of Public Health, University of Saskatchewan, Saskatoon, Canada.
PLoS One. 2020 Dec 16;15(12):e0242911. doi: 10.1371/journal.pone.0242911. eCollection 2020.
The prevalence of cognitive impairment or dementia is of public health concern globally. Accurate estimates of this debilitating condition are needed for future public health policy planning. In this study, we estimate prevalence and modifiable risk factors for cognitive impairment by sex over approximately 16 years.
Canadian Study of Health and Aging (CSHA) baseline data conducted between 1991-1992 were used to measure the prevalence of cognitive impairment and dementia among adults aged 65+ years. The standard Modified Mini-Mental State Examination (3MS) was used for the screening test for cognitive impairment. We compared the CSHA data with Canadian Community Health Survey-Healthy Aging (CCHS-HA) conducted between 2008-2009. The CCHS-HA used a four-dimension cognitive module to screen for cognitive impairment. Only survey community-dwelling respondents were included in the final sample. After applying exclusion criteria, final samples of (N = 8504) respondents in the CSHA sample and (N = 7764) respondents for CCHS-HA sample were analyzed. To account for changes in the age structure of the Canadian population, prevalence estimates were calculated using age-sex standardization to the 2001 population census of Canada. Logistic regression analyses were used to examine predictors of cognitive impairment. A sex stratified analysis was used to examine risk factors for cognitive impairment in the survey samples.
We found that prevalence of cognitive impairment among respondents in CSHA sample was 15.5% in 1991 while a prevalence of 10.8% was reported in the CCHS-HA sample in 2009, a 4.7% reduction [15.5% (CI = 14.8-16.3), CSHA vs 10.8% (CI = 10.1-11.5), CCHS-HA]. Men reported higher prevalence of cognitive impairment in CSHA study (16.0%) while women reported higher prevalence of cognitive impairment in CCHS-HA (11.6%). In the multivariable analyses, risk factors such as age, poor self-rated health, stroke, Parkinson's disease, and hearing problems were common to both cohorts. Sex differences in risk factors were also noted.
This study provides suggestive evidence of a potential reduction in the occurrence of cognitive impairment among community-dwelling Canadian seniors despite the aging of the Canadian population. The moderating roles of improved prevention and treatment of vascular morbidity and improvements in the levels of education of the Canadian population are possible explanations for this decrease in the cognitive impairment.
认知障碍或痴呆的患病率是全球公共卫生关注的问题。为了未来的公共卫生政策规划，需要对这种使人衰弱的疾病进行准确的估计。在这项研究中，我们在大约 16 年的时间里按性别估算了认知障碍的患病率和可改变的风险因素。
使用 1991-1992 年进行的加拿大老龄化健康研究（CSHA）的基线数据来衡量 65 岁以上成年人的认知障碍和痴呆患病率。标准的改良简易精神状态检查（3MS）用于认知障碍的筛查测试。我们将 CSHA 数据与 2008-2009 年进行的加拿大社区健康调查-健康老龄化（CCHS-HA）进行了比较。CCHS-HA 使用四维度认知模块来筛查认知障碍。只有接受调查的社区居住者被纳入最终样本。在应用排除标准后，CSHA 样本的最终样本（N=8504）和 CCHS-HA 样本的最终样本（N=7764）进行了分析。为了考虑到加拿大人口年龄结构的变化，使用年龄性别标准化方法对 2001 年加拿大人口普查数据进行了患病率估计。使用逻辑回归分析检查认知障碍的预测因素。使用性别分层分析检查调查样本中认知障碍的风险因素。
我们发现，CSHA 样本中受访者的认知障碍患病率在 1991 年为 15.5%，而在 2009 年 CCHS-HA 样本中的患病率为 10.8%，降低了 4.7%[15.5%（CI=14.8-16.3），CSHA 与 10.8%（CI=10.1-11.5），CCHS-HA]。男性在 CSHA 研究中报告的认知障碍患病率较高（16.0%），而女性在 CCHS-HA 中报告的认知障碍患病率较高（11.6%）。在多变量分析中，年龄、自我报告的健康状况差、中风、帕金森病和听力问题等风险因素在两个队列中都很常见。还注意到了风险因素中的性别差异。
尽管加拿大人口老龄化，但这项研究提供了有说服力的证据，表明居住在社区的加拿大老年人中认知障碍的发生可能有所减少。血管发病率的预防和治疗的改善以及加拿大人口教育水平的提高可能是认知障碍减少的原因。
