Valenzuela Michael J, Sachdev Perminder
School of Psychiatry, University of New South Wales, The Neuropsychiatric Institute, Prince of Wales Hospital, NSW, Australia.
Psychol Med. 2007 Jul;37(7):1015-25. doi: 10.1017/S003329170600938X. Epub 2006 Nov 20.
Brain reserve is a property of the central nervous system related to complex mental activity which may mediate the course and clinical expression of brain injury. Since there is no instrument that comprehensively assesses complex mental activity through the lifespan, we developed and tested the Lifetime of Experiences Questionnaire (LEQ) in a prospective study of healthy ageing.
The LEQ assesses educational, occupational and cognitive lifestyle activities at different stages through life. Test-retest, item analysis and Item Response Theory (IRT) were used to determine reliability. Dimensionality was evaluated using factor analysis. Validity was established through IRT analysis of test performance, correlation with an extant contemporaneous instrument (Cognitive Activities Scale; CAS) and prediction of global cognitive change over 18 months controlling for age, baseline cognition and hypertension.
In a sample of healthy older individuals (n=79) the LEQ was found to be consistent, coherent and discriminate between individuals with high and low mental activity levels. Factor analysis revealed a dominant factor which loaded heavily on education, occupation and leisure activity. Total LEQ was significantly correlated with the CAS. Furthermore, individuals with higher LEQ scores showed less cognitive decline over 18 months, independent of covariates (r=0.37, p=0.003).
The LEQ is a reliable and valid instrument for assessing complex lifespan mental activity which is protective against cognitive decline. The LEQ is therefore proposed as a useful tool for estimating brain reserve in older individuals and further development is anticipated.
脑储备是中枢神经系统的一种特性，与复杂的精神活动相关，可能介导脑损伤的病程和临床表现。由于尚无一种仪器能在整个生命周期内全面评估复杂的精神活动，我们在一项健康老龄化的前瞻性研究中开发并测试了终身经历问卷（LEQ）。
LEQ评估人生不同阶段的教育、职业和认知生活方式活动。采用重测法、项目分析和项目反应理论（IRT）来确定信度。使用因子分析评估维度。通过对测试表现的IRT分析、与现有同期仪器（认知活动量表；CAS）的相关性以及在控制年龄、基线认知和高血压的情况下对18个月内整体认知变化的预测来确定效度。
在一组健康老年人样本（n = 79）中，发现LEQ具有一致性、连贯性，能够区分精神活动水平高和低的个体。因子分析揭示了一个主要因子，该因子在教育、职业和休闲活动方面负荷很重。LEQ总分与CAS显著相关。此外，LEQ得分较高的个体在18个月内认知下降较少，与协变量无关（r = 0.37，p = 0.003）。
LEQ是一种可靠且有效的工具，用于评估对认知衰退具有保护作用的复杂的终身精神活动。因此，LEQ被提议作为评估老年人脑储备的有用工具，预计将进一步发展。
