Association of objective and subjective socioeconomic markers with cognitive impairment among older adults: cross-sectional evidence from a developing country

Age-related changes in connected speech production: evidence from eye-tracking in the culturally adapted picture description task

Purpose

Age-related changes in connected speech production remain a subject of debate, yielding inconsistent findings across various tasks and measures. This study aimed to investigate the effects of aging on picture description tasks using two types of pictures: a standardized picture (the Beach picture) and a culturally and linguistically modified picture tailored for Korean speakers (the Han River picture).

Method

Twenty-four young adults and 22 older adults participated in two picture description tasks while their eye movements were recorded. Word-level linguistic variables were used to assess informativeness (Correct Information Units per minute) and productivity (noun and verb counts per utterance) of connected speech production. Eye-movement measures were employed to evaluate real-time cognitive processing associated with planning connected speech (pre-speech fixation counts and durations; eye fixations before the speech onset of each utterance).

Results and conclusions

The findings revealed age-related declines in linguistic measures, with older adults exhibiting decreased CIUs per minute and smaller counts of nouns and verbs per utterance. Age-related changes in eye movement measures were evident in that older adults displayed longer pre-speech fixation durations. Unlike younger adults, older adults exhibited higher pre-speech fixation counts on the Han River picture compared to the Beach picture, suggesting cognitive challenges in performing the task that requires producing more words and detailed descriptions. These results suggest that aging is associated with reduced informativeness and productivity of connected speech, as well as a decline in cognitive processing efficiency.

Examining factors contributing to the socioeconomic inequalities in handgrip strength among older adults in India: a decomposition analysis

The purpose of this study was to examine (a) the socioeconomic status (SES)-related inequalities associated with handgrip strength (HGS); and (b) the extent to which several demographic, health, and behavioral factors contributed to such SES disparities in HGS among older adults in India. Data were drawn from the 2017-2018 wave 1 of the Longitudinal Ageing Study of India (LASI). The study sample included 27,707 older adults (13,199 men and 14,508 women) aged 60 years and older. HGS was assessed using a handheld Smedley's Hand Dynamometer with a cut-off of 19.5 kg for men and 12.5 kg for women. Bivariate analysis showed the weighted percentage distribution of weak HGS across respondent characteristics. Multivariate logistic regression assessed factors linked to weak HGS. The concentration curve and index (CCI) was used to determine the inequalities in the prevalence of weak HGS by wealth index scores. Wagstaff's decomposition approach was used to test the contribution of each explanatory variable to weak HGS. Around 9% of older adults in this study reported a weak HGS. It was significantly higher among those aged 80 or older (19.21%) and males (15.55%). Weak HGS was concentrated among older adults from poor SES (CCI: 0.05, p < 0.001). A higher percentage of wealth-based inequality in weak HGS was explained by being underweight (38.83%), belonging to the richest wealth quintile (27.95%), and having a higher subjective social status (32.20%). Moreover, about 23.29% of the inequality in weak HGS was explained by Western region and 22.54% by female gender. Additionally, having a secondary level of education explained a higher percentage (22.09%) of inequality, followed by current working status (- 20.68%). Rural residence (13.08%), limitations in instrumental activities of daily living (IADL) (12.21%), and engagement in yoga-related activities (11.55%) explained a higher percentage of wealth-based inequalities. The findings provide evidence of significant SES-related inequalities in HGS and the contribution of various demographic, health, and behavioral factors to such inequality. As such, public health policies and programs focusing on reducing the burden of disability must consider the contribution of social and economic equity to the preservation of muscle strength among older adults.

Association between subjective social status and physical frailty in older adults in India: perceived discrimination and III-treatment as mediators and moderators

BACKGROUND

While extensive research exists on physical frailty, including in low- and middle-income countries like India, studies have yet to appraise whether perceived social standing is associated with physical frailty. As such, this study examines (1) the association between subjective social status (SSS) and physical frailty among older adults in India; and (2) whether this association is mediated and moderated by perceived discrimination and experiences of III-treatment.

METHODS

Data came from the Longitudinal Aging Study in India with a sample of 31,464 older adults aged 60 and above. Physical frailty was assessed using an adapted version of the frailty phenotype developed by Fried and colleagues. SSS was assessed using the Macarthur scale. Multivariable logistic regression models along with Karlson-Holm-Breen (KHB) methodology were employed to examine the direct association, mediational pathways, and the interactions.

RESULTS

The prevalence of frailty was 30.65% and those with lowest SSS reported higher prevalence of frailty (42.06%). After adjusting for several confounders, odds of frailty were lower among persons with high SSS relative to those with low SSS, and the variance explained by the SSS was higher than that explained by household consumption quintiles. Moreover, the association between SSS and frailty was mediated and moderated by perceived discrimination and III-treatment.

CONCLUSIONS

Our findings underscore that when examining the association between socioeconomic status (SES) and physical frailty, it is important to consider SSS given that perceived social status likely reflects the less apparent psychosocial components associated with SES, and that perceived discrimination and III-treatment both mediate and moderate the association between SSS and physical frailty is critical to identifying those older Indians most susceptible to the functional health implications of lower SSS.

Subjective social status and functional and mobility impairments among older adults: life satisfaction and depression as mediators and moderators

BACKGROUND

While functional and mobility impairments (FMIs) have garnered the attention of health researchers in low and middle-income countries (LMICs), including India, research has yet to explore whether and to what extent the perception of one's social status is associated with FMIs. We fill this gap in the literature by examining (1) the association between subjective social status (SSS) and FMIs among older adults in India and (2) whether this association between SSS and FMIs is mediated and moderated by life satisfaction and depression.

METHODS

Data come from the 2017-18 wave 1 of the Longitudinal Aging Study in India (LASI) with a sample of 31,464 older adults aged 60 years and above. FMIs were assessed using established scales on impairments in activities of daily living (ADLs), instrumental activities of daily living (IADLs), and mobility. SSS was assessed using the Macarthur scale. Life satisfaction was measured using responses to five statements gauging respondent's overall satisfaction with life. Depression was calculated using the shortened version of the Composite International Diagnostic Interview (CIDI-SF). Multivariable regression was employed to examine the association between variables, and the interaction terms and Karlson-Holm-Breen (KHB) method were used separately to test the mediation and moderation effects.

RESULTS

39.11% of the sample had a low SSS, 8.26% were depressed, and 32.07% reported low life satisfaction. A total of 8.74%, 10.91%, and 8.45% of the study population reported at least one impairment in ADL, IADL, and mobility, respectively. Older adults in the higher SSS group were less likely to have ADL impairment (beta: -0.017, CI: -0.030, -0.0032) and mobility impairment (beta: -0.044, CI: -0.076, -0.013). Depression moderated the association between SSS and mobility impairment (p-value: 0.025), and life satisfaction moderated the association between SSS and ADL impairments (p-value: 0.041) and SSS and IADL impairments (p-value: 0.037). Depression mediated 20.28%, 31.88%, and 18.39% of the associations of SSS with ADL, IADL, and mobility impairments, respectively. Similarly, life satisfaction mediated 23.24%, 52.69%, and 27.22% of the associations of SSS with ADL, IADL, and mobility impairments.

CONCLUSIONS

That SSS is associated with FMIs among older Indians, even after considering their objective socioeconomic status (SES), suggests that the use of SSS is relevant to the study of health inequalities in India. The finding that life satisfaction and depression mediate and moderate this association is crucial in pinpointing those older Indians at risk of the functional and mobility-related repercussions of lower SSS.

Socioeconomic Disparities in Cognitive Functioning Trajectories Among Older Filipinos: Applying the Characteristics Approach

Health functioning declines with age, but there are disparities in its progression with regard to socioeconomic status, particularly education attainment, income, and wealth. This paper focused on the use of the characteristics approach to present the trajectories of cognitive performance among older adults with different education and wealth levels in the Philippines. Using an analytical sample of 5209 adults aged at least 60 years, extracted from the first wave of the 2018 Longitudinal Study on Ageing and Health in the Philippines, it was observed that having higher levels of education delayed lower cognitive performance, whereby men had further gains than women. Greater wealth and income were also shown to slow diminishing cognitive performance, and women gained more in this regard. Viewing health only from an age perspective is limiting; and the results show that the older population is heterogeneous and social gradients exhibit disparities in health performance at later ages.

The direct and mediating effects of cognitive impairment on the occurrence of falls: a cohort study based on community-dwelling old adults

Background

Cognitive impairment has been reported to be associated with falls in older adults. However, the complex relationship among falls, cognitive impairment and its associated factors, which could be targeted with specific interventions, remains to be elucidated. This study aimed to examine the direct effects of cognitive impairment on falls, to identify the factors associated with cognitive impairment and to explore the mediation role of cognitive impairment in the association of fall with cognition related factors.

Methods

This 1-year follow-up cohort study enrolled old adults aged 60  years or over. Information about demographic and anthropometric characteristics, fall outcomes, function and nutritional status were collected through face-to-face interview. Cognitive function was evaluated by the Montreal Cognitive Assessment (MoCA). Multivariable regression analyses were used to test the association between cognitive impairment and falls and to identify the factors related to cognitive impairment. Additionally, we conduct causal mediation analyses to estimate the mediation effects of cognitive impairment in the pathways of fall occurrence.

Results

Of the 569 participants included in this study, 366 (64.32%) had cognitive impairment, 96 (16.87%) had fall history in the past 1  year, 81 (14.24%) experienced fall and 47 (8.26%) received treatment because of falling during the 1-year follow-up. The association between cognitive impairment and 1-year fall risk was confirmed after adjusting for multiple covariates [odds ratio (OR):2.03, 95% confidence interval (CI): 1.13-3.80]. IADL disability, depression and low grip strength were associated with a higher prevalence of cognitive impairment. While overweight, higher education and higher income level were found to be related to a lower risk of cognitive impairment. Among these associated factors, cognitive impairment mediated the positive association of falling with IADL ability and depression, and a negative relationship with education and income level.

Conclusion

Our study not only confirmed the direct influence of cognitive impairment on fall risk in older adults, but also suggested a mediating role that cognitive impairment played in the pathways of fall occurrence. Our finding could help develop more specific interventions for fall prevention.

Life course rural/urban place of residence, depressive symptoms and cognitive impairment among older adults: findings from the Longitudinal Aging Study in India

BACKGROUND

Given the unique socioeconomic structures, and the rural/urban differentials in the prevalence of mental illnesses in the country, this study aimed to explore the associations of childhood, adulthood and late-life rural/urban place of residence with mental health outcomes, namely depressive symptoms and cognitive impairment, among older adults in India. The study also examined the relationship between older individuals' life-course rural/urban place of residence and late-life mental and cognitive health.

METHODS

Utilizing data from the Longitudinal Aging Study in India (n = 28,027 older adults age 60 years and above), the study employed multivariable logistic and linear regression models to examine the association between urban/rural residential status, life-course residence, depressive symptoms and cognitive impairment among older adults.

RESULTS

Childhood and adulthood place of residence was not associated with depressive symptoms in older men and women. Current rural place of residence was positively associated with depressive symptoms in older women [adjusted odds ratio (aOR): 1.37, confidence interval (CI): 1.05-1.80] but not men. Childhood [aOR: 1.88, CI: 1.16-3.04], adulthood [aOR: 2.00, CI: 1.26-3.16] and current rural residence [aOR: 1.93, CI: 1.27-2.91] was positively associated with cognitive impairment in men. Only current rural residence [aOR: 1.71, CI: 1.29-2.27] was associated with cognitive impairment in women. There was no significant association between life-course place of residence and depressive symptoms except in case of lifetime rural residence Respondents with urban-urban-urban (childhood-adulthood-current) place of residence were less likely to have depressive symptoms [adjusted coefficient (aCoef.): -0.14, CI: -0.21- -0.07] compared to those with rural-rural-rural place of residence. There were significant associations between life-course residence and cognitive impairment except among rural-urban-rural and urban-rural-rural migrants, showing an urban advantage in cognitive function among older adults.

CONCLUSIONS

This study showed significant associations between life-course residence and depressive symptoms among permanent rural/urban residents. The study also showed significant associations between life-course residence and cognitive impairment except among rural-urban-rural and urban-rural-rural migrants. Considering the rural disadvantage in mental and cognitive health among older adults, the government should continue to support policies that can improve access to education and healthcare among people residing in rural areas and women, in particular. The findings also urge social scientists and gerontologists in particular, to consider the importance of lifetime historical context while evaluating mental and cognitive health of older persons.

Low neighborhood deprivation buffers against hippocampal neurodegeneration, white matter hyperintensities, and poorer cognition

There is increasing recognition that socioeconomic inequalities contribute to disparities in brain and cognitive health in older adults. However, whether neighborhood socioeconomic status (SES) buffers individuals with low individual SES against neurodegeneration, cerebrovascular disease, and poorer cognitive function is not well understood. Here, we evaluated whether neighborhood deprivation (Townsend deprivation index) interacted with individual SES (composite household income and education levels) on hippocampus volume, regional cortical thickness, white matter hyperintensities, and cognition in 19,638 individuals (mean age = 54.8) from the UK Biobank. We found that individuals with low individual SES had the smallest hippocampal volumes, greatest white matter hyperintensity burden, and poorest cognition if they were living in high deprivation neighborhoods but that these deleterious effects on brain and cognitive function were attenuated if they were living in low deprivation neighborhoods (p for interactions < .05). While neighborhood deprivation did not interact with individual SES to influence regional cortical thickness, higher neighborhood deprivation was independently associated with lower cortical thickness in 16 regions (false discovery rate q < .05). Across multiple brain indices and cognitive function analyses, we found converging evidence suggesting that low neighborhood deprivation may have a neuroprotective effect against neurodegeneration, cerebrovascular pathology, and cognitive impairment, particularly in vulnerable individuals with low household income and education levels.

Does tandem balance test predict cognitive impairment among older adults? Findings from Longitudinal Ageing Study in India, 2017-18

BACKGROUND

Ageing entails a decline in physical and functional abilities including a reduced body balance due to complex integration and coordination of sensory acuity, motor control, neural and cognitive functions. This study aimed to examine the association between tandem balance test and cognitive impairment among older Indian adults. The study also examined the gender differentials in the associations with an interaction analysis.

METHODS

Data for this study were drawn from the recent release of the Longitudinal Ageing Study in India (2017-18). The total sample size for the present study included 26,539 older adults age 60 years and above. Descriptive statistics and bivariate analysis were used to present the preliminary results. Two sample proportion test was used to evaluate the significance for gender differences. Further, multivariable binary logistic regression analysis was used to evaluate the independent association of balance test performance and cognitive impairment among older adults.

RESULTS

Nearly 16% of male and 26% of female older adults could not finish full tandem test in this study. There were significant gender differences in cognitive impairment among older adults (male-6.5% and female-18.9%). The likelihood of cognitive impairment was significantly higher among older adults who could not finish the full tandem test compared to those who finished the tandem test [AOR: 1.22; CI: 1.09-1.36]. The interaction model revealed that older females who could not finish the full tandem test were 2.11 times significantly more likely to be cognitively impaired in reference to older males who finished the full tandem test [AOR: 2.11; CI: 1.81,2.45]. Similarly, older females who finished the full tandem test were 2.42 times significantly more likely to be cognitively impaired in reference to older males who finished the full tandem test [AOR: 2.42; CI: 2.02,2.88].

CONCLUSION

The findings of the study suggest that healthcare professionals working with older adults should consider the results of a balance test to screen for their risk of cognitive impairment. Results from the relationship between failing to finish the tandem test and cognitive impairment may be helpful for identifying older men and women who are at higher risk of experiencing mobility decline and their progression to dementia.

Decomposition of caste differential in life satisfaction among older adults in India

BACKGROUND

Being a multi-cultured country, India has varied social groups which largely shape the lives of individuals. Literature has shown that life satisfaction is highly associated with the social status of individuals. However, changing age dynamics (growing older) and definition of life among people presses the need to understand whether the additional years of life in older adults are manifested with the disparity in life satisfaction among the Scheduled Caste (SC)/ Scheduled Tribes (ST) and non-SC/ST social groups in recent years. The present study explored the factors contributing to such differences in life satisfaction across social groups.

METHODS

This study used data from the Longitudinal Aging Study in India conducted during 2017-18. The analytical sample of the study was 30,370 older adults. Life satisfaction was the outcome variable with a score ranging from 5 to 35. Descriptive statistics and bivariate analysis were conducted. Simple linear regression analysis was used to establish the association between the outcome and explanatory variables. Further, the Blinder-Oaxaca decomposition model was used to analyse the role of explanatory factors in the caste difference in life satisfaction among older people.

RESULTS

Overall, the life satisfaction score among older adults in the study was 23.9 (SD- 7.3). Older adults from non-SC/ST group had significantly higher likelihood of having life satisfaction in comparison to older adults from SC/ST group [Coef: 0.31; CI: 0.14, 0.49]. The decomposition results showed that the model explained 74.3% of the caste gap (between SC/ST and non-SC/ST) in life satisfaction among older adults in India. Subjective social status (39.0%) was widening the gap for life satisfaction among older adults from SC/ST and non-SC/ST group. Similarly, level of education (15.2%) followed by satisfaction with living arrangement (13.2%) and place of residence (5.3%) contributed for widening the gap for life satisfaction among older adults from SC/ST and non-SC/ST group. Region of country (- 11.5%) followed by self-rated health (- 3.0%) and major depression (- 2.7%) contributed for narrowing down the gap for life satisfaction among older adults from SC/ST and non-SC/ST group.

CONCLUSION

Older adults belonging to non-SC/ST groups were more likely to have a higher level of life satisfaction than those from the SC/ST group. Factors like subjective social status, educational level, living arrangement satisfaction, and place of residence explained the caste differential in life satisfaction among older adults. In addition, factors such as psychological health and perceived health status should be the area of concern and special focus for policy makers and researchers in terms of reducing social inequalities in wellbeing among older population.