Validation of the Cognitive Assessment of Later Life Status (CALLS) instrument: a computerized telephonic measure

<p>Abstract</p> <p>Background</p> <p>Brief screening tests have been developed to measure cognitive performance and dementia, yet they measure limited cognitive domains and often lack construct validity. Neuropsychological assessments, while comprehensive, are too costly and time-consuming for epidemiological studies. This study's aim was to develop a psychometrically valid telephone administered test of cognitive function in aging.</p> <p>Methods</p> <p>Using a sequential hierarchical strategy, each stage of test development did not proceed until specified criteria were met. The 30 minute Cognitive Assessment of Later Life Status (CALLS) measure and a 2.5 hour in-person neuropsychological assessment were conducted with a randomly selected sample of 211 participants 65 years and older that included equivalent distributions of men and women from ethnically diverse populations.</p> <p>Results</p> <p>Overall Cronbach's coefficient alpha for the CALLS test was 0.81. A principal component analysis of the CALLS tests yielded five components. The CALLS total score was significantly correlated with four neuropsychological assessment components. Older age and having a high school education or less was significantly correlated with lower CALLS total scores. Females scored better overall than males. There were no score differences based on race.</p> <p>Conclusion</p> <p>The CALLS test is a valid measure that provides a unique opportunity to reliably and efficiently study cognitive function in large populations.</p

Is cognitive lifestyle associated with depressive thoughts and self-reported depressive symptoms in later life?

© 2015, The Author(s). Key components of cognitive lifestyle are educational attainment, occupational complexity and engagement in cognitively stimulating leisure activities. Each of these factors is associated with experiencing fewer depressive symptoms in later life, but no study to date has examined the relationship between overall cognitive lifestyle and depressive symptoms. This task is made more complex because relatively few older participants in cross-sectional studies will be currently experiencing depression. However, many more will show evidence of a depressive thinking style that predisposes them towards depression. This study aimed to investigate the extent to which cognitive lifestyle and its individual components are associated with depressive thoughts and symptoms. Two hundred and six community-dwelling participants aged 65+ completed the depressive cognitions scale, the geriatric depression scale and the lifetime of experiences questionnaire, which assesses cognitive lifestyle. Correlational analysis indicated that each of the individual lifestyle factors—education, occupational complexity and activities in young adulthood, mid-life and later life—and the combined cognitive lifestyle score was positively associated with each other and negatively with depressive symptoms, while all except education were negatively associated with depressive thoughts. Depressive thoughts and symptoms were strongly correlated. Cognitive lifestyle score explained 4.6 % of the variance in depressive thoughts and 10.2 % of the variance in depressive symptoms. The association of greater participation in cognitive activities, especially in later life, with fewer depressive symptoms and thoughts suggests that preventive interventions aimed at increasing participation in cognitively stimulating leisure activity could be beneficial in decreasing the risk of experiencing depressive thoughts and symptoms in later life

The impact of ENSO on Southern African rainfall in CMIP5 ocean atmosphere coupled climate models

We study the ability of 24 ocean atmosphere global coupled models from the Coupled Model Intercomparison Project 5 (CMIP5) to reproduce the teleconnections between El Niño Southern Oscillation (ENSO) and Southern African rainfall in austral summer using historical forced simulations, with a focus on the atmospheric dynamic associated with El Niño. Overestimations of summer rainfall occur over Southern Africa in all CMIP5 models. Abnormal westward extensions of ENSO patterns are a common feature of all CMIP5 models, while the warming of the Indian Ocean that happens during El Niño is not correctly reproduced. This could impact the teleconnection between ENSO and Southern African rainfall which is represented with mixed success in CMIP5 models. Large-scale anomalies of suppressed deep-convection over the tropical maritime continent and enhanced convection from the central to eastern Pacific are correctly simulated. However, regional biases occur above Africa and the Indian Ocean, particularly in the position of the deep convection anomalies associated with El Niño, which can lead to the wrong sign in rainfall anomalies in the northwest part of South Africa. From the near-surface to mid-troposphere, CMIP5 models underestimate the observed anomalous pattern of pressure occurring over Southern Africa that leads to dry conditions during El Niño years

Predicting the seasonal evolution of southern African summer precipitation in the DePreSys3 prediction system

We assess the ability of the DePreSys3 prediction system to predict austral summer precipitation (DJF) over southern Africa, defined as the African continent south of 15°S. DePresys3 is a high resolution prediction system (at a horizontal resolution of ~ 60 km in the atmosphere in mid-latitudes and of the quarter degree in the Ocean) and spans the long period 1959–2016. We find skill in predicting interannual precipitation variability, relative to a long-term trend; the anomaly correlation skill score over southern Africa is greater than 0.45 for the first summer (i.e. lead month 2–4), and 0.37 over Mozambique, Zimbabwe and Zambia for the second summer (i.e. lead month 14–16). The skill is related to the successful prediction of the El-Nino Southern Oscillation (ENSO), and the successful simulation of ENSO teleconnections to southern Africa. However, overall skill is sensitive to the inclusion of strong La-Nina events and also appears to change with forecast epoch. For example, the skill in predicting precipitation over Mozambique is significantly larger for the first summer in the 1990–2016 period, compared to the 1959–1985 period. The difference in skill in predicting interannual precipitation variability over southern Africa in different epochs is consistent with a change in the strength of the observed teleconnections of ENSO. After 1990, and consistent with the increased skill, the observed impact of ENSO appears to strengthen over west Mozambique, in association with changes in ENSO related atmospheric convergence anomalies. However, these apparent changes in teleconnections are not captured by the ensemble-mean predictions using DePreSys3. The changes in the ENSO teleconnection are consistent with a warming over the Indian Ocean and modulation of ENSO properties between the different epochs, but may also be associated with unpredictable atmospheric variability