Catherine Grotz

Occupational activity and cognitive reserve: implications in terms of prevention of cognitive aging and Alzheimer's disease.

This paper investigates the relationship between the concept of activity (including both professional and nonprofessional) and cognitive functioning among older European individuals. In this research, we used data collected during the first wave of SHARE (Survey on Health, Ageing and Retirement in Europe), and a measurement approach known as stochastic frontier analysis, derived from the economic literature. SHARE includes a large population (n > 25,000) geographically distributed across Europe, and analyzes several dimensions simultaneously, including physical and mental health activity. The main advantages of stochastic frontier analysis are that it allows estimation of parametric function relating cognitive scores and driving factors at the boundary and disentangles frontier noise and distance to frontier components, as well as testing the effect of potential factors on these distances simultaneously. The analysis reveals that all activities are positively related to cognitive functioning in elderly people. Our results are discussed in terms of prevention of cognitive aging and Alzheimer’s disease, and regarding the potential impact that some retirement programs might have on cognitive functioning in individuals across Europe.

Why is later age at retirement beneficial for cognition? Results from a French population-based study

ObjectiveTo determine whether and how age at retirement influences the risk of dementia. The association between the age at retirement, the number of working years and the risk of dementia was evaluated over 12 years of follow-up.DesignA prospective population-based study.SettingThree-City cohort, a French population-based study of community-dwelling individuals aged 65 to 95.ParticipantsThe sample consisted of 1,658 non-demented participants at baseline.MeasurementsAll participants were evaluated at home at the initial visit and at two years interval for a period of 12 years. An active research of dementia was conducted at each follow-up; all suspected cases were analysed by an independent committee of neurologists. Information regarding retirement age and number of working years was collected at baseline using a structured questionnaire.ResultsThe multivariate Cox model, including both the age at retirement and the number of working years and adjusted for potential confounders, revealed that the risk of dementia was independently associated with the age at retirement (p=0.022) but not with the number of working years (p=0.296).ConclusionAlthough our results are in accordance with previous studies (i.e., older age at retirement is associated with decreased risk of dementia), it provides additional information regarding the possible explanation for such results. Given that a longer working life did not reduce the risk of dementia, the age at retirement cannot be considered as a new factor of cognitive reserve but rather seems to be a psycho-social vulnerability factor. Further evidence is necessary to identify work and retirement related factors that influence the association between the age at retirement and the risk of dementia.

Retirement Age and the Age of Onset of Alzheimer’s Disease: Results from the ICTUS Study

Objectives To test whether deferred retirement is associated with delayed onset of Alzheimer’s disease (AD), and, if so, to determine whether retirement age still predicts the age at onset of AD when two potential biases are considered. Methods The study sample was gathered from the Impact of Cholinergic Treatment Use/Data Sharing Alzheimer cohort (ICTUS/DSA), a European study of 1,380 AD patients. Information regarding retirement age, onset of symptoms and covariates was collected at baseline whereas age at diagnosis was gathered from the patient’s medical record prior to study entry. Linear mixed models, adjusted for gender, education, occupation, center, country, household income, depression and cardiovascular risk factors were conducted on 815 patients. Results (1) The global analyses (n = 815) revealed that later age at retirement was associated with later age at diagnosis (β = 0.31, p < 0.0001); (2) once the selection bias was considered (n = 637), results showed that this association was weaker but remained significant (β = 0.15, p = 0.004); (3) once the bias of the reverse causality (i.e., the possibility that subjects may have left the workforce due to prior cognitive impairment) was considered (n = 447), the effect was no longer significant (β = 0.06, p = 0.18). Conclusion The present study supports that there is an association between retirement age and age at onset of AD. However, the strength of this association appears to be overestimated due to the selection bias. Moreover, the causality issue remains unresolved. Further prospective investigations are mandatory in order to correctly address this question.

The association of timing of retirement with cognitive performance in old age: The role of leisure activities after retirement

BACKGROUND The role of timing of retirement on cognitive functioning in old age is inconclusive so far. Therefore, the present study set out to investigate the association of timing of retirement with cognitive performance and its interplay with key correlates of cognitive reserve in a large sample of older adults. METHODS Two thousand two hundred and sixty three older adults served as sample for the present study. Different psychometric tests (Trail Making Test part A (TMT A), Trail Making Test part B (TMT B), Mill Hill) were administered. In addition, individuals were interviewed on their retirement, occupation, educational attainment, and regarding 18 leisure activities that have been carried out after retirement. RESULTS Earlier retirement (compared to retirement at legal age) was significantly associated with better performance in the TMT A, the TMT B, and the Mill Hill vocabulary test. Moderation analyses showed that in individuals with a moderate number of leisure activities in old age, earlier retirement was related to better cognitive performance, but not in those with a relatively large number of leisure activities. Hierarchical regression analyses revealed that entering leisure activities as additional predictor significantly increased explained variance in the cognitive measures over and above all other investigated markers of cognitive reserve (i.e. occupation and education). CONCLUSIONS Present data further corroborate the view that leisure activities even in old age may lead to further enrichment effects and thereby may be related to better cognitive functioning. The role of engaging in activities in the context of major life events such as retirement is discussed.

How should proxies of Cognitive Reserve be evaluated in a population of healthy older adults

BACKGROUND While some tools have been developed to estimate an individuals cognitive reserve (CR), no study has assessed the adequacy of the method used for assessing these CR proxy indicators. Therefore, we aimed to determine the most appropriate method to estimate CR by comparing two approaches: (1) the common assessment of CR proxies in the literature (e.g. years of education) and (2) the calculation of a comprehensive index based on most significant parameters used in the estimation of CR. METHODS Data on CR proxies (i.e. education, occupation, and leisure activities) were obtained in a sample of 204 older adults. Regression analyses were used to develop the two indices of CR (i.e. ICR-standard and ICR-detailed) and to determine which index best represented the level of ones CR. RESULTS The ICR-standard was calculated using a combination of the three most common measures of reserve in the literature: number of schooling years, complexity of the primary occupation, and amount of current participation in stimulating activities. The ICR-detailed was calculated using the most significant parameters (established in initial analyses) of CR: highest level of education combined with the number of training courses, last occupation, and amount of current participation in social and intellectual activities. The comparison of both indices showed that higher levels of ICR-standard and ICR-detailed were associated with a greater minimization of the effects of age on cognition. However, the ICR-detailed was more strongly associated to this minimization than the ICR-standard, suggesting that the ICR-detailed best reflect ones CR. CONCLUSIONS This study is the first to show that it is of great importance to question methods measuring CR proxies in order to develop a clinical tool allowing a comprehensive and accurate estimation of CR.

Psychological transition and adjustment processes related to retirement: influence on cognitive functioning

ABSTRACT Objective: To investigate the relationship between psychological transition and adjustment to retirement and cognitive performances in older adults. Methods: The studys sample was taken from the Approche Multidisciplinaire Intégrée cohort, a French prospective study of retirees from agriculture, aged 65 and over, living in rural settings in southwestern France. The cross-sectional analyses were conducted on a sample of 590 elderly people without dementia at baseline and for whom information on perception of the work setting, experience of the retirement transition and adaptation to retirement life (nine variables) as well as neuropsychological measures (global cognitive functioning, episodic memory, verbal fluency, attention and psychomotor speed) were available at first visit. Results: Multivariable linear regression analyses, including nine variables related to retirement and adjusted for potential confounding factors, indicated that three of them – positive consideration of former work situation, development of new activities during retirement and good adaptation to free time – were associated with better cognitive performances. Conclusions: We found that several factors proved to be determinants of good cognitive functioning at retirement and could serve as a basis for the development of more efficient intervention programs aimed at helping retirees to maintain good cognitive functioning after retirement.

Management of demented patients with urinary incontinence: A case study

Objective: To assess whether a demented patient with urinary incontinence (UI) could learn to use an adapted version of timed voiding (i.e., instead of being led by a caregiver, the patient learns to perform timed voiding by herself). Indeed, UI affects a large number of patients with dementia and creates a substantial burden to the caregiver. UI is the most common complaint at the time of institutionalization and it is often the cause of premature institutionalization. Timed voiding is a promising intervention, but one whose effectiveness remains to be demonstrated. Additionally, timed voiding has the disadvantage of being constraining for caregivers, requiring them to be present to stimulate the patient to urinate at each of the scheduled occasions. Method: The present intervention required the patient to learn (1) to associate an auditory signal from a timer to the action of urination, (2) to reprogram the timer, using the spaced retrieval technique. An ABAB paradigm was used to assess the effectiveness of this program to eliminate urinary accidents. Results: The results of the intervention showed that the use of the timer was effective in helping the patient to reduce her urinary leaks from 1.5 diurnal accidents per week to zero during four months. Conclusion: UI in patients with dementia seems treatable. Such intervention could contribute to delay institutionalization of patients with dementia through maintaining their autonomy and reducing the burden of caregivers.

Complexity of Work and Incident Cognitive Impairment in Puerto Rican Older Adults

OBJECTIVE We investigated complexity of work in main occupation in relation to incident cognitive impairment in older Puerto Ricans. METHOD A population-based sample of 1,673 adults age 60+ for the Puerto Rican Elderly: Health Conditions (PREHCO) study was used. Cognition was measured at baseline and 4 years later using the Mini-Mental Cabán (MMC), with scoring 1.5 SD below the MMC score adjusted for age, education, gender, and reading ability comprising cognitive impairment. Complexity scores were derived from the 1970 U.S. Census, 1977 and 2000 Dictionary of Occupational Titles, and 2001 O*Net. RESULTS Controlling for baseline age, gender, childhood economic hardship, adult money problems, depressive symptoms, and self-reported health, greater scores for most work complexity measures were associated with significantly lower risk of cognitive impairment (ps < .05), with significant odds ratios ranging between 0.74, reflecting 26% reduction in risk for every extra standard deviation of complexity, and 0.81. Controlling for education reduced these effects slightly but also reduced most associations to nonsignificant. The results were stronger for those with less childhood economic hardship or education (ps < .05). DISCUSSION Complexity of work may reduce risk of cognitive impairment in Puerto Rican older adults, especially when combined with favorable childhood economic conditions and higher educational attainment.