Methods of cognitive function investigation in the Longitudinal Study on Adult Health (ELSA-Brasil)

CONTEXT AND OBJECTIVE:Many uncertainties concerning risk factors and evolution of cognitive disorders remain. We describe the methods and preliminary results from the investigation of the cognitive function in the Longitudinal Study on Adult Health (ELSA-Brasil).DESIGN AND SETTING:Multicenter cohort study on public employees at six public teaching and research institutions.METHODS:The participants were interviewed and examined to obtain a broad range of social, clinical and environmental characteristics. The following standardized tools were used to assess memory, language and visuospatial and executive functions: words or figure memory test; semantic (animals) and phonemic (letter F) verbal fluency tests; and trail test B.RESULTS:15,101 out of 15,105 participants took the cognitive tests: 54% were women; the mean age was 51 years; and 52% had a university degree. 14,965 participants (99%) did the word test and 136 (1%) did the figure test due to low schooling level. The scores from the semantic verbal fluency tests (mean = 18.42 ± 5.29; median = 18 words) were greater than the scores from the phonemic verbal fluency tests (mean = 12.46 ± 4.5; median = 12 words). The median time taken to perform the trail test was 1.6 minutes.CONCLUSION:The large cohort size, of young age, and the extensive amount of clinical and epidemiological data available will make it possible to investigate the prognostic value of biological, behavioral, environmental, occupational and psychosocial variables over the short and medium terms in relation to cognitive decline, among adults and elderly people.

研究背景与目的：目前学界对认知障碍的危险因素及其病程演变仍存在诸多未解之处。本研究阐述巴西成人健康纵向研究（Longitudinal Study on Adult Health, ELSA-Brasil）中认知功能调查的研究方法与初步结果。
研究设计与研究地点：本研究为多中心队列研究，研究对象为6所公共教学与科研机构的公职人员。
研究方法：对参与者进行访谈与体格检查，以获取多维度的社会、临床及环境特征数据。本研究采用以下标准化工具评估记忆、语言、视空间与执行功能：词语或图形记忆测验；语义（动物类别）与语音（字母F）言语流畅性测验；以及连线测验B。
研究结果：15105名参与者中共有15101人完成了认知测验；其中女性占比54%，平均年龄51岁，52%的参与者拥有大学学历。14965名参与者（99%）完成了词语记忆测验，另有136名参与者（1%）因受教育程度较低完成了图形记忆测验。语义言语流畅性测验得分（平均值=18.42±5.29；中位数=18个词语）高于语音言语流畅性测验得分（平均值=12.46±4.5；中位数=12个词语）。完成连线测验的中位耗时为1.6分钟。
研究结论：本队列样本量大、受试者年龄偏轻，且可获取丰富的临床与流行病学数据，这将为开展短期及中期范围内成人与老年人群体中与认知衰退相关的生物学、行为学、环境、职业及社会心理变量的预后价值研究提供支撑。