Late Life Disability Research Articles

PHYSICAL FUNCTIONING AND BODY SIZE IN MID-LIFE WOMEN: THE STUDY OF WOMEN’S HEALTH ACROSS THE NATION

Abstract To evaluate patterns of age-related changes in physical functioning (PF) and associations with body size, we utilized data from the longitudinal Study of Women’s Health Across the Nation (SWAN). Participants (n=1,793) with self-reported SF-36 PF data at visit 4 (2000-01; mean age:50.0 years ±2.7), visit 15 (2016-17), plus one additional visit were included. Body weight and waist circumference were measured at each visit; change from visits 4 to 15 was calculated. Five PF trajectories were identified using latent class growth modeling (% of women): (1) persistently low (4.1%); (2) start moderate and improve slightly (5.4%); (3) start high and decline slightly (24.0%); (4) persistently high (59.5%); and (5) start high and decline substantially (7.0%). Participants with persistently low PF (Group 1) lost weight during follow-up (mean change: -3.2% body weight) whereas there was little change in all other groups (ANOVA p< 0.0001). Women with persistently low PF (Group 1) had < 2% increase in waist circumference over follow-up; all other groups had more than double that increase (range: 4.1%-6.1%; ANOVA p=0.002). No statistically significant differences in anthropometry changes across the PF groups were observed after adjustment for sociodemographic and time-variant health characteristics. PF trajectories may be associated with changes in body weight or waist circumference during midlife and transition to older adulthood; however, these associations may be explained by other major health-related variables. Future research is needed to understand the complex interplay between PF and body size, particularly for women at-risk for late-life disability that may benefit from preventive efforts in mid-life.

The prevalence of vision impairment and blindness among older adults in India: findings from the Longitudinal Ageing Study in India.

Vision impairment and blindness are strongly associated with aging and late-life disability. While home to about 17% of the world's population, an estimated 25% of visually impaired people globally live in India. This proportion is expected to increase as India's population rapidly ages and continues to grow. There is a need for up-to-date epidemiologic data on the prevalence of vision impairment and blindness in India and on the socioeconomic determinants of poor vision, especially among older adults, to promote visual and overall health and well-being in later life. This paper uses newly available data from Wave 1 (2017-2019) of the population-based Longitudinal Ageing Study in India to estimate the overall and sex-specific prevalence of presenting visual acuity impairment and blindness among individuals aged 45 and older at the national level and for all constituent states and union territories. Overall, 33.8% (95% confidence interval: 33.31%, 34.26%) of the Indian population aged 45 and older had distance visual acuity impairment or was blind (visual acuity in the better-seeing eye < 20/40). The age-standardized prevalence varied considerably among states (22.3-54.6%), and women were more likely than men to be visually impaired or blind in all states. Near visual acuity impairment was also highly prevalent (43.0%, 95% confidence interval: 42.45%, 43.46%). Vision impairment and blindness were more common among marginalized groups and were associated with lower socioeconomic status. Findings from this study are relevant for surveillance of vision health, design of targeted eye care policies and programs and efforts to promote human and economic development.

Association between oral health markers and decline in muscle strength and physical performance in later life: longitudinal analyses of two prospective cohorts from the UK and the USA

Poor oral health could be associated with changes in musculoskeletal health over time. This aim of this study was to investigate the longitudinal relationship between oral health and decline in physical function in later life. We did a prospective analysis of two cohorts of older adults (aged 70 years or older) including men from the British Regional Heart Study (BRHS; n=612), and men and women from the Health, Aging and Body Composition (Health ABC) Study (n=1572), followed up for about 8 years. Data were available for clinical or self-reported oral health measures, muscle (grip) strength, and physical performance (chair stand and gait speed). ANCOVA models were used to assess the association between oral health and follow-up physical function scores. Multivariate logistic regression models were used to examine the associations between oral health and decline in physical function over the follow-up period. In the BRHS, changes in oral health and physical function were also assessed. All models were adjusted for relevant sociodemographic, behavioural, and health-related factors. In the BRHS, complete tooth loss and difficulty eating were associated with weaker grip strength at follow-up, and periodontal status was associated with decline in gait speed. In the Health ABC Study, complete tooth loss, poor self-rated oral health, and the presence of one oral health problem were associated with slower gait speed at follow-up. In both studies, dry mouth was associated with declines in physical function. In the BRHS, deterioration of dentition (tooth loss) over the follow-up period was associated with decline in chair stand speed (adjusted odds ratio 2·34 [95% CI 1·20-4·46]), as was deterioration in difficulty eating (2·41 [1·04-5·60]). Oral health problems are associated with poorer physical function and greater decline in physical function in older adults, and could be an indicator of individuals at risk of reduced physical capacity and subsequent frailty and disability in later life. The Dunhill Medical Trust and the US National Institutes of Health-National Institute of Dental and Craniofacial Research.

Participation Among Community-Dwelling Older Adults During the COVID-19 Pandemic: A Cross-Sectional Analysis.

Participation in life situations is a critical aspect of health recognized by the World Health Organization. Guidelines to prevent spreading of COVID-19 place older adults at risk of worsening participation. The purpose of this study was to identify the factors associated with participation during the COVID-19 pandemic among community-dwelling older adults living in Hamilton, Ontario, Canada. Participants were recruited from identified census dissemination areas in Hamilton. Participants completed surveys either by phone or online during the months of May to August 2020. Measures were organized into factors related to body functions and structures, activities, participation, as well as personal and environmental contextual factors using the International Classification of Functioning, Disability, and Health (ICF) framework. Multivariable regression analysis was conducted to identify factors associated with participation as measured by the Late-Life Disability Instrument's (LLDI) frequency and limitations scales. A total of 272 older adults completed the survey (78 [7.3] years; 70% female). Use of a walking aid, driving status, perceived mental health status, nutrition risk, and physical function explained 48.2% of the variance observed in the LLDI-frequency scale scores. Use of a walking aid, driving status, perceived mental health status, receiving health assistance, and physical function explained 38.5% of the variance observed in the LLDI-limitation scale scores. Results highlighted factors across multiple ICF domains that are associated with participation restriction among a sample of community-dwelling older adults during the pandemic. Participation during the pandemic was greatest in those that were able to walk without needing to use a walking aid, being a licensed and current driver, perceiving good to excellent mental health, and having greater physical function. Our findings contribute to the literature on older adult participation during lockdowns, restrictions, pandemics, and/or other similar circumstances.

People with COPD have greater participation restrictions than age-matched older adults without respiratory conditions assessed during the COVID-19 pandemic.

Participation restriction has detrimental effects for older adults but it is unknown how participation differs for people with chronic obstructive pulmonary disease (COPD) compared to older adults of the same age without respiratory conditions. We compared scores on the Late Life Disability Instrument (LLDI) between people with COPD (study group) and a random sample of older adults (control group). Participants with COPD (study group) were recruited from two hospitals in Ontario and age- and sex-matched with a ratio of 1:2 with participants from a random sample of community-dwelling older adults who did not report having respiratory conditions (control group). The study group completed the LLDI prior to the COVID-19 pandemic and the control group completed the LLDI at the end of the first wave of the pandemic. LLDI frequency and limitation scores were compared between groups using Wilcoxon rank-sum tests. Forty-six study group participants (mean age 74.2 (SD 5.5) years) and 92 control group participants (mean age 74.4 (SD 5.4) years) were included. Fifty-four percent of the participants were female. The majority of the study group had severe COPD (median forced expiratory volume in one second of 34.5 (25th-75th percentile 27.0-56.0) % predicted). LLDI sores were lower for the study group compared to the control group for both the frequency (median difference -5.4 points, p<0.001) and limitation (median difference -7.6 points, p<0.001) domains. The personal subscale demonstrated the largest magnitude of difference between groups (median difference -13.4 points) and the social subscale demonstrated the smallest magnitude of difference (-5.2 points). People with COPD had greater participation restrictions than a random sample of older adults without ongoing respiratory conditions. The differences seen in participation between the two groups may have been reduced due to temporal confounding from the COVID-19 pandemic. While participation is relevant to all older adults, our results suggest that it is especially important that it be assessed in those with COPD.

Associations of source-specific PM2.5 and incident disability in older U.S. adults: the Health Retirement Study

Keywords: Air Pollution, emission sources, Activities of Daily Living, PM2.5 Background and Aims: Late-life disability is a common endpoint of the chronic health conditions that affect people as they age. Although fine particulate matter (PM2.5) is associated with chronic conditions that contribute to disability, associations with disability itself are understudied, and the most toxic emission sources have yet to be identified. We evaluated the association between long-term exposure to PM2.5 from specific emission sources and disability. Methods: We used biennial survey data between 2006 and 2016 on Activities of Daily Living (ADL) from participants &amp;#x3e;65 years of the Health and Retirement Study. Using a spatiotemporal prediction model, we estimated 10-year PM2.5 concentrations at participants&amp;#x27; residences and multiplied these values by spatially-resolved fractions of PM2.5 from sources including agriculture, energy production, industry, transportation, fires, and windblown dust, derived from a chemical transport model. We used Cox models to estimate the risk of incident ADL disability per 1-µg/m³ source-specific PM2.5, adjusting for individual- and area-level confounders, time, geography, and sampling weights. Results: Among 11,782 adults (72&amp;#xb1;6.8 years), 37% reported a new disability during follow-up. Overall, both total PM2.5 and source-specific PM2.5 were associated with increased incident of ADL disability. A 1-µg/m³ increment in total PM2.5 corresponded to a 2% (95% CI: 1.00, 1.04) greater hazard of ADL. In single-sector models, PM2.5 from each source was also positively associated with incident ADL. After adjusting for PM2.5 from other sources, associations with agriculture, non-road and road transportation, non-coal energy production, and windblown dust PM2.5 remained, whereas no associations were observed for the other sources. Conclusions: We found evidence that higher levels of PM2.5 from some but not all sources were associated with increased risk of disability, suggesting that selective interventions could be effective at improving health and function in late-life.

Trajectories of Physical Function and Disability Over 12 Months in Older Adults With Chronic Low Back Pain.

Understanding prognosis is critical for clinical care and health policy initiatives. The purpose of this study was to determine whether distinct prognostic trajectories of physical function and disability exist in a cohort of 245 community-dwelling older adults with chronic low back pain (LBP), and to characterize the demographic, health, and pain-related profiles of each trajectory subgroup. All participants underwent standard clinic examinations at baseline, 3 months, 6 months, and 12 months. At each time point, the Late Life Function & Disability Instrument (LLFDI) was used to measure general physical function (LLFDI Function) and disability (LLFDI Disability-Limitation); the Quebec LBP Disability Questionnaire was used to measure disability due to pain. Growth mixture modeling (GMM) was performed on each outcome to identify distinct trajectory classes/subgroups; baseline demographic (eg, age and sex), health (eg, comorbidities, depressive symptoms, and physical activity level), and pain-related (eg, LBP intensity, pain-related fear, and pain catastrophizing) characteristic profiles were compared across subgroups. GMM statistics revealed an optimal number of 3 to 4 trajectory subgroups, depending on the outcome examined. Subgroups differed across demographic, health, and pain-related characteristics; the classes with the most favorable prognoses had consistent profile patterns: fewer depressive symptoms, fewer comorbidities, higher physical activity levels, lower LBP intensities, less pain-related fear, and less pain catastrophizing. Our findings indicate that several distinct trajectory subgroups exist that would have been masked by observing mean cohort change alone. Furthermore, subgroup characteristic profiles may help clinicians identify likely prognostic trajectories for their patients. Future research should focus on identifying modifiable risk factors that best predict group membership, and tailoring interventions to mitigate the risk of poor prognosis.

Role of Medical Insurance in Reducing Place‐based Health Disparities: Functional Disability in Rural Appalachia

AbstractRural Appalachia, including the entire state of West Virginia, is characterized by high health disparities. Such place‐based health disparities contribute to disability across the lifespan and may exacerbate morbidity and disability in late life. Thus, examinations of the contributors to morbidity and disability at mid‐and late‐life are needed to inform policies and programs.Using the most recent data from the Centers for Disease Control and Prevention's (CDC) Behavioral Risk Factor Surveillance System (BRFSS), we examine some of the social determinants of health (e.g., age, gender, education, income) as predictors of access to health care and functional ability among 4,867 adults living in West Virginia. Access to health care was indexed by three variables, including whether one had financial barriers to medical care, the number of personal medical care professionals one saw, and the recency of wellness exams. Functional ability was indexed using items assessing difficulty with dressing, climbing stairs, and doing errands. The model fit the data well for the entire sample, X2 (DF = 29, N = 4867) = 411.30, p &lt; .001, CFI = .94, RMSEA = .052. Post hoc models with the age groups fit well, although some differences in specific paths emerged. Our results suggest that policies and programs that increase medical access for current middle‐aged and older adults might decrease functional ability. Moreover, as the younger adults age into midlife, they enter with lower economic and educational resources, further exacerbating their lack of access to health care and increasing disability in future generations of West Virginians.

Assessing Relationships between Physically Demanding Work and Late-Life Disability in Italian Nonagenarian Women Living in a Rural Area.

As more and more persons live into their 90s and beyond, investigating causes of disability in the oldest-old population is relevant for public health implications to plan preventive strategies and rehabilitation interventions. A negative association between physically demanding work and midlife physical function has been shown, but there is a paucity of longitudinal studies investigating possible work-related long-term effects in the oldest old. This study investigates the relationship between physically demanding work exposure and late-life physical performances, disability, general health status, and quality of life in a sample of women aged 90 years and over inside the Mugello Study. Sociodemographic data, cognitive and functional status, lifestyle, medical history, drug use, and work history were collected from 236 participants. Farmers had a lower percentage of individuals with preserved independence in basic activities of daily living compared to other occupations. However, in the multivariate analysis, only a higher cognitive function remained associated with functional independence. While confirming the well-known association between cognitive and functional decline in very old age, our results do not support the hypothesis that the negative effects of physical work exposure observed in midlife are relevant to predict disability in nonagenarian women.

Late-Life Disability and Care: An Update From the National Health and Aging Trends Study at Its 10-Year Mark.

Late-Life Disability and Care: An Update From the National Health and Aging Trends Study at Its 10-Year Mark.

Description and Functional Benefits of Meeting Frequency, Intensity, and Time of Resistance and Cardiovascular Exercises: A Study of Older Adults in a Community-Based, Slow-Stream Rehabilitation, Hospital-to-Home Transition Program.

This prospective cohort study described cardiovascular and resistance exercises completed by older adults in a community-based, slow-stream rehabilitation, hospital-to-home transition program; compared exercises completed to the American College of Sports Medicine (ACSM) exercise guidelines; and, assessed differences in Late Life Function and Disability Index (LLFDI)-Function Component (FC) between older adults who met and did not meet the ACSM guidelines. Descriptive statistics and Factorial ANCOVA were conducted. For cardiovascular exercise 59.3% of participants met frequency, 73.4% met intensity, and 35.9% met time. For resistance exercise, 67.2% of participants met frequency, 42.2% met intensity, and 76.6% number of repetitions. Participants who met both frequency and time for cardiovascular exercise had higher LLFDI-FC scores, as did those who met intensity and/or number of repetitions for resistance exercise. The findings provide support that older adults engaged in a slow-stream rehabilitation program can meet the ACSM exercise guidelines for community-dwelling older adults, and that meeting the guidelines improves function.

Do trajectories of occupational physical activity from midlife to retirement predict limitations in mobility and disability in later life? A multi-cohort study

Do trajectories of occupational physical activity from midlife to retirement predict limitations in mobility and disability in later life? A multi-cohort study

Factors associated with participation in life situations in people with COPD

ObjectiveTo examine potential determinants of participation frequency and limitations in people with Chronic Obstructive Pulmonary Disease (COPD).MethodsFor this secondary analysis, we grouped the following factors using the International Classification of Functioning, Disability and Health (ICF) components: age, psychological distress (Hospital Anxiety and Depression Scale (HADS)), gait aid use, supplemental oxygen use, grip strength, modified Medical Research Council Dyspnea scale, Short Physical Performance Battery, and Six-Minute Walk Test (6MWT). Participation was measured using the frequency and limitation domains of the Late Life Disability Instrument (LLDI). Relationships between factors and participation were examined using linear regression.ResultsNinety-six participants (age 68.7 ± 8.1 yrs; FEV1 %pred 34 IQR 25–54) were included in the analysis. Factors were linked to four ICF components: activity, body functions, personal, and environmental factors. The final model for LLDI-frequency contained HADS, use of gait aid, and 6MWT (F (3, 81) = 27.69 (p < .001), R2 = 0.51), and for LLDI-limitations, the final model included age, HADS, and 6MWT (F (3, 82) = 19.74 (p < .001), R2 = 0.42).DiscussionParticipation in life situations in people with COPD is associated with multiple ICF components. Psychological distress (i.e., anxiety and depression symptoms) and mobility were important determinants of participation frequency and limitations. Prospective studies are needed to confirm these relationships.

A Standardized Assessment of Movement-evoked Pain Ratings Is Associated With Functional Outcomes in Older Adults With Chronic Low Back Pain.

Despite high prevalence estimates, chronic low back pain (CLBP) remains poorly understood among older adults. Movement-evoked pain (MeP) is an understudied factor in this population that may importantly contribute to disability. This study investigated whether a novel MeP paradigm contributed to self-reported and performance-based function in older adults with CLBP. This secondary analysis includes baseline data from 230 older adults with CLBP in the context of a prospective cohort study. The Repeated Chair Rise Test, Six Minute Walk Test, and Stair Climbing Test were used to elicit pain posttest LBP ratings were aggregated to yield the MeP variable. Self-reported and performance-based function were measured by the Late Life Function and Disability Index (LLFDI) scaled function score and Timed Up-and-Go Test (TUG), respectively. Robust regression with HC3 standard errors was used to model adjusted associations between MeP and both functional outcomes; age, sex, body mass index, and pain characteristics (ie, intensity, quality, and duration) were utilized as covariates. MeP was present in 81.3% of participants, with an average rating of 5.09 (SD=5.4). Greater aggregated posttest MeP was associated with decreased LLFDI scores (b=-0.30, t=-2.81, P=0.005) and poorer TUG performance (b=0.081, t=2.35, P=0.020), independent of covariates. LBP intensity, quality and duration were not associated with the LLFDI or TUG, (all P>0.05). Aggregated posttest MeP independently contributed to worse self-reported and performance-based function among older adults with CLBP. To understand long-term consequences of MeP, future studies should examine longitudinal associations between MeP and function in this population.

Utility of the Late Life Function and Disability Instrument (LLFDI) in rehabilitation services for older adults

Employing Foreign Educated Nurses (FENs) helps address Registered Nurse (RN) shortages in long-term care (LTC) in the United States (US). However, examination of factors explaining differences in their employment outcomes relative to US Educated Nurses (USENs) is limited. This study uses 2018 National Sample Survey of Registered Nurses data to compare income, work hours, job satisfaction, and human capital, defined as personal characteristics (knowledge, work experience) and behaviors (job mobility), of FENS and USENs working full-time in LTC. A human capital score, consisting of highest nursing education, skill certifications, state licensures, years of experience, multi-state employment history, and multi-lingual status was constructed. Covariates included nurse demographics, direct care role, and ability to practice to full scope. Covariate-adjusted group differences in employment outcomes and human capital were compared using ANCOVA and logistic regression. Mediation analyses explored whether human capital explained FEN vs USEN differences. FENs earned higher hourly wages (p=0.0169), worked fewer hours annually (p=0.0163), and reported greater human capital (p<.0001) compared to USENs. FENs and USENs, however, had similar annual salaries (p=0.3101) and job satisfaction (p=0.1674). Human capital mediated FEN vs USEN effects on hourly wages but not annual work hours. FENs’ higher levels of human capital partially account for FEN vs USEN differences in hourly wages. Application of the human capital concept advanced our ability to examine differences in employment outcomes and highlight aspects of the value that FENs contribute to LTC settings.

Remote Monitoring Activity Trajectory-Associated Weight Loss and Functional Ability in Obese Older Adults

Functional decline in older adults can often be mitigated by physical activity. As older adults increasing adopt wearable technology, an understanding of how remotely monitored activity is associated with clinical outcomes is needed. Data was analyzed from two cohorts of older adults with obesity (□65 years, BMI (□30kg/m2)) who completed weekly dietary and exercise-based weight loss interventions (n=93). Follow-up time varied between cohorts (n=37: 12-weeks; n=56: 16 weeks). All participants were provided a Fitbit to monitor physical activity. Baseline and follow up weight, 6-minute walk distance, grip strength, and Late Life Function and Disability Instrument (LLFDI) were collected. We used k-means clustering for longitudinal data to identify physical activity trajectories from Fitbit steps at the daily level. Linear regression models tested for differences in each outcome between trajectories, adjusting for age and sex. Baseline characteristics did not vary across cohorts: mean age 72.7±4.5 years, 76.5% were female, and mean BMI was 36.4±5.1 kg/m2. Two physical activity trajectories were identified, termed high and low activity based on differences in mean daily steps (7,476±4,117 vs. 2,960±2,453, p <0.001). Participants in the high activity group experienced a 2.4% reduction in weight (p <0.001) and a 4.74% increase in LLFDI score (p=0.007) relative to the low activity cluster. Other outcomes were not significantly different between trajectories. These results demonstrate the potential for remote monitoring data to elucidate longitudinal trends in weight and functional ability. As such, older adults’ use of wearable technology may facilitate improvements in weight and functional ability in the community.

Gender Differences in Avoiding Later-Life Disability: A Life Course Perspective

Identifying the early origins of adult health has underscored how experiences in the earliest stages of life can have lasting consequences. Whereas most research on the early origins of adult health has linked childhood conditions to worse health in adulthood, this study considered whether childhood conditions are associated with healthy aging. Guided by the World Health Organization’s emphasis on functional ability as a core component of healthy aging, the present study investigated the association between childhood social conditions and avoiding later-life limitations in basic and instrumental activities of daily living, referred to as disability-free status. This study also tested potential health-related and socioeconomic mediators and examined whether these life course antecedents of healthy aging vary by gender. Analyzing a sample of 9,376 adults over age 50 from the Health and Retirement Study over 10 years (2006-2016) revealed that childhood socioeconomic disadvantage reduced the odds of avoiding disability over time. For women, adult health lifestyles mediated this relationship whereas adult socioeconomic status (SES) mediated this relationship for men. Conditional indirect effects indicated that the mediational effects of body mass and education differed between men and women (i.e., moderated mediation). The direct effects of childhood and adult SES also varied by gender. These results demonstrate that the life course antecedents, especially SES, of healthy aging are distinct for men and women. Interventions should prioritize reducing early-life exposure to socioeconomic disadvantage, especially for women. Given the gendered differences in the mediating effects, midlife interventions can be tailored for men and women.

Putting age-related hearing loss on the public health agenda in Australia.

Hearing loss is one of the most common long-term health conditions associated with ageing, and a considerable contributor to Australia's late-life disability burden. Acquired hearing loss in adulthood presents significant challenges for the social, physical, mental and cognitive health of many Australians. These wide-ranging individual and societal impacts have been highlighted by a number of high-profile national inquiries into Australia's hearing health during the past decade. Yet hearing loss remains poorly recognised and is undertreated in many communities. In this perspective article we argue that effective public health measures such as limiting occupational and recreational exposure to hazardous noise and ototoxic chemicals, promoting hearing health behaviours, early detection, improved access to hearing health services, and urban design, are all critical to mitigating these adverse outcomes. We also make the case for updated epidemiological data about hearing loss among older Australians.

Ocular manifestations in children with developmental delay in an eye hospital of northern Bangladesh

Background: The aim of this study was to identify common ocular manifestations in children with developmental delay in an eye hospital of northern part of Bangladesh.Methods: It was a retrospective medical record review of children with developmental delay who attended the pediatric ophthalmology department in an eye hospital from January 2019 to December 2019. Data were collected for their age, gender, past medical history, ophthalmic examination findings and systemic problems. Ophthalmic examination included examination of lid and adnexa, anterior and posterior segment examination and assessment of squint and refraction.Results: Medical records of 102 with developmental delay were identified and studied (59 boys and 43 girls, mean age 1.57 years, 53.9% aged &lt;1 year). Of these children, 44 (43.1%) were referred by the pediatricians. The most common past medical histories were perinatal asphyxia (42.2%), history of convulsion (30.4%), neonatal seizures (9.8%) and history of speech delay (1%). On ophthalmic examination, 30 (29.5%) had poor vision, 20 (19.6%) had refractive error, 23 (22.5%) had Strabismus and 11 (10.8%) had nystagmus. Optic atrophy was also observed among 11 children (10.8%).Conclusions: Ocular manifestations are commonly seen in children with developmental delay which can be cause of severe visual impairment and overall disability in later life. Hence an early ophthalmologic screening and intervention in these children by developing good referral network between ophthalmologist and pediatricians can help to substantially improve the developmental and academic achievement.

Late-life disability trajectories in Yoruba Nigerians and the Spanish population: a state space model in continuous time

Objectives We compared the trajectory of activities of daily living (ADL) in a nationally representative sample of older Nigerians with their Spanish peers and identified factors to explain country-specific growth models. Methods Data from two household multistage probability samples were used, comprising older adults from Spain (n = 2,011) and Nigeria (n = 1,704). All participants underwent assessment for ADL. Risk factors including sex, household income, urbanicity, years of education, depression, alcohol consumption and smoking were assessed using validated methods. State-space model in continuous time (SSM-CT) methods were used for trajectory comparison. Results Compared with Nigerians (µADL80=0.44, SE = 0.015, p < 0.001), Spanish older adults had higher disability scores (µADL80=1.23, SE = 0.021, p < 0.001). In SSM-CT models, the rate of increase in disability was faster in Nigerians (Nigeria: β = 0.061, p<.01; Spain: β = 0.028, p < 0.010). An increasing course of disability in the Spanish sample was predicted by female sex, lower education and depression diagnosis. Conclusion The rate of increase in disability was faster in older Nigerians living in an economically disadvantaged context.