Mild cognitive impairment (MCI) and dementia in a sample of adults in the city of Bogotá

ABSTRACT The low prevalence of dementia described in communities is likely due to the low sensitivity of screening tests and an absence of evaluation by specialists. OBJECTIVE: To estimate the prevalence of mild cognitive impairment (MCI) and dementia in adults older than 50 years. METHODS: A two-phase, cross-sectional study was conducted by specialists to evaluate cognition and associated demographic risk factors in 1,235 independent community-dwelling adults from Bogotá. In Phase I, screening was performed using the MMSE and MoCA tests. In Phase II, after application of a comprehensive neuropsychological battery with neurologic and psychiatric evaluations, a cognitive diagnosis was established by consensus. RESULTS: The prevalence found for MCI was 34% and for dementia was 23%. MCI was associated with incomplete high school, OR=1.74 (95%CI=1.23-2.45), and with an age of 70-79 years, OR=1.93 (95%CI=1.47-2.53). A total of 73% of MCI cases were amnestic. Dementia was associated with incomplete primary education, OR=8.98 (95%CI=5.56-14.54), complete primary education, OR=6.23 (95%CI=3.70-10.47), and age older than eighty years, OR=3.49 (95%CI=2.23-5.44). CONCLUSION: The prevalence of dementia found was greater than the rates reported in previous studies. Low educational level was the main risk factor for cognitive impairment and should be considered in strategic planning for the local health system.

摘要 社区中报道的痴呆患病率偏低，可能源于筛查试验灵敏度不足，且缺乏专科医师评估。
研究目的：评估50岁以上成年人轻度认知障碍（mild cognitive impairment, MCI）与痴呆的患病率。
研究方法：本研究为两阶段横断面研究，由专科医师对来自波哥大的1235名独立居住于社区的成年人开展认知功能及相关人口统计学危险因素评估。第一阶段采用简易精神状态检查表（Mini-Mental State Examination, MMSE）与蒙特利尔认知评估量表（Montreal Cognitive Assessment, MoCA）进行筛查；第二阶段在实施成套神经心理测评并结合神经科与精神科评估后，通过专家共识确定认知障碍诊断。
研究结果：轻度认知障碍患病率为34%，痴呆患病率为23%。轻度认知障碍与未完成高中学业（优势比（Odds Ratio, OR）=1.74，95%置信区间（Confidence Interval, CI）=1.23~2.45）、年龄70~79岁（OR=1.93，95%CI=1.47~2.53）显著相关。其中73%的轻度认知障碍病例为遗忘型。痴呆与未完成小学学业（OR=8.98，95%CI=5.56~14.54）、完成小学学业（OR=6.23，95%CI=3.70~10.47）以及年龄80岁以上（OR=3.49，95%CI=2.23~5.44）显著相关。
研究结论：本次研究测得的痴呆患病率高于既往研究报道的水平。低受教育程度是认知障碍的主要危险因素，在当地卫生系统的战略规划中应予以充分考量。