Variation in Thresholds for Reporting Mobility Disability Between National Population Subgroups and Studies

Time perspective profile and self-reported health on the EQ-5D

OBJECTIVES

Time perspective (TP) is a psychological construct that is associated with several health-related behaviours, including healthy eating, smoking and adherence to medications. In this study, we aimed to examine the associations of TP profile with self-reported health on the EQ-5D-5L and to detect which domains display response heterogeneity (cut-point shift) for TP.

METHODS

We conducted a secondary analysis of EQ-5D-5L data from a representative general population sample in Hungary (n = 996). The 17-item Zimbardo Time Perspective Inventory was used to measure individuals' TP on five subscales: past-negative, past-positive, present-fatalist, present-hedonist and future. The associations between TP subscales and EQ-5D-5L domain scores, EQ VAS and EQ-5D-5L index values were analysed by using partial proportional odds models and multivariate linear regressions.

RESULTS

Respondents that scored higher on the past-negative and present-fatalist and lower on the present-hedonist and future subscales were more likely to report more health problems in at least one EQ-5D-5L domain (p < 0.05). Adjusting for socio-economic and health status, three EQ-5D-5L domains exhibited significant associations with various TP subscales (usual activities: present-fatalist and future, pain/discomfort: past-negative and future, anxiety/depression: past-negative, present-fatalist, present-hedonist and future). The anxiety/depression domain showed evidence of cut-point shift.

CONCLUSIONS

This study identified response heterogeneity stemming from psychological characteristics in self-reported health on the EQ-5D-5L. TP seems to play a double role in self-reported health, firstly as affecting underlying health and secondly as a factor influencing one's response behavior. These findings increase our understanding of the non-health-related factors that affect self-reported health on standardized health status measures.

Health Needs and Their Relationship with Life Expectancy in People with and without Intellectual Disabilities in England

Health needs are common in people living with intellectual disabilities, but we do not know how they contribute to life expectancy. We used the Clinical Practice Research Datalink (CPRD) linked with hospital/mortality data in England (2017–2019) to explore life expectancy among people with or without intellectual disabilities, indicated by the presence or absence, respectively, of: epilepsy; incontinence; severe visual loss; severe visual impairment; severe mobility difficulties; cerebral palsy and PEG feeding. Life expectancy and 95% confidence intervals were compared using flexible parametric methods. At baseline, 46.4% (total n = 7794) of individuals with intellectual disabilities compared with 9.7% (total n = 176,807) in the comparison group had ≥1 health need. Epilepsy was the most common health need (18.7% vs. 1.1%). All health needs except hearing impairment were associated with shorter life expectancy: PEG feeding and mobility difficulties were associated with the greatest loss in life years (65–68% and 41–44%, respectively). Differential life expectancy attenuated but remained (≈12% life years lost) even after restricting the population to those without health needs (additional years expected to live at 10 years: 65.5 [60.3, 71.1] vs. 74.3 [73.8, 74.7]). We conclude that health needs play a significant role but do not explain all of the differential life expectancy experienced by people with intellectual disabilities.

Health Trajectories in Swedish Centenarians

Background

Longitudinal studies describing centenarians’ health trajectories are currently lacking. We compared health trajectories of older adults becoming centenarians and their shorter-living counterparts in terms of chronic diseases, disability, and cognitive decline.

Methods

We identified 3,573 individuals participating in the Kungsholmen Project and the Swedish National Study on Aging and Care in Kungsholmen who lived <100 years and 222 who survived to their 100th birthday. Trajectories of chronic diseases, disability (impaired activities of daily living), and cognitive status were obtained via linear mixed models over 13 years.

Results

Centenarians had fewer chronic diseases than noncentenarians. Before age 85, centenarians showed slower health changes. In centenarians, multimorbidity, disability, and cognitive impairment occurred 4 to 9 years later than in noncentenarians. After age 85, the speed of accumulation of chronic diseases, disabilities, and cognitive decline accelerated in centenarians. At age 100, 39% of the centenarians were cognitively intact and 55% had escaped disability. Only 5% were free of multimorbidity at age 100. When compared with their shorter lived counterparts, in terms of years spent in poor health, centenarians experienced more years with multimorbidity (9.4 vs 6.8 years; p < .001), disability (4.3 vs 3.1 years; p = .005), and cognitive impairment (6.3 vs 4.3 years; p < .001).

Conclusions

Older people who become centenarians present a delay in the onset of morbidity, but spend more years in this condition compared to their shorter lived peers. The observation of older adults’ health trajectories might help to forecast healthier aging, and plan future medical and social care delivery.

How do Japanese rate the severity of different diseases and injuries?-an assessment of disability weights for 231 health states by 37,318 Japanese respondents

Background

Disability weights (DWs) are weight factors that reflect the severity of health states for estimates of disability-adjusted life years. A new set of global DWs was published for the Global Burden of Diseases and Injuries (GBD) 2013 study, which relied on sampling from various world regions, but included little data for countries in East Asia. This study aimed to measure DWs in Japan using comparable methods, and compare the results with previous estimates from the GBD 2013 DW study.

Methods

We conducted a web-based survey in 2019 to estimate DWs for 231 health states for the Japanese population. The survey included five new health states but otherwise followed the method of the GBD DW measurement study. The survey consisted of 15 paired comparison (PC) questions and 3 population health equivalence questions (PHE) per respondent. We analyzed PC data using probit regression and rescaled results to DW units between 0 (equivalent to full health) and 1 (equivalent to death).

Findings

We considered 37,318 nationally representative respondents. The values of the resulting DWs ranged from 0.707 (95% uncertainty interval (UI) 0.527–0.842) for spinal cord injury at neck level (untreated) to 0.004 (UI 0.001–0.009) for mild anemia. High correlation between Japanese DW and GBD 2013 DW was observed, but there was considerable disagreement. Out of 226 comparable health states, 55 (24.3%) showed more than a factor-of-two difference, of which 41 (74.6%) had a higher value in Japanese DW. Many of the health states with higher DW in the Japan study were injuries, including amputation and fracture, and hearing and vision loss, while mental, behavioral, and substance use disorders generally tended to be lower.

Conclusions

This study has created an empirical basis for assessment of Japanese DWs of health status. The findings from this study based on the Japanese population suggest that there might be contextual differences in rating the severity of health states compared to previous surveys conducted elsewhere.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12963-021-00253-4.

Change in Mobility: Consistency of Estimates and Predictors Across Studies of Older Adults

OBJECTIVES

This study compares estimates and determinants of within-individual changes in mobility across surveys of older U.S. adults.

METHODS

Data come from the Health and Retirement Study (HRS) and the Midlife in the United States (MIDUS) study. Measures of mobility comprise self-reported level of difficulty with walking several blocks, going up several flights of stairs, lifting and carrying 10 pounds, and stooping. Predictors include sociodemographic characteristics and indicators of health and health behaviors. We pool the datasets and estimate weighted lagged dependent variable logistic regression models for each activity, assessing cross-study differences using interaction terms between a survey indicator and relevant variables.

RESULTS

Estimates of declines in mobility differ substantially across surveys for walking, lifting and carrying, and stooping, but there are no between-survey differences in the probability of (not) recovering from a limitation. With the exception of age, determinants of change are similar between studies. For lifting/carrying and stooping, the age-related increase in developing limitations is less steep at younger ages for HRS respondents than MIDUS respondents, but steeper at older ages.

DISCUSSION

To compare estimates of mobility change across surveys, mobility measures would need to be harmonized. Determinants of mobility change, however, are more comparable.

Wearable Sensors Technology as a Tool for Discriminating Frailty Levels During Instrumented Gait Analysis

Background and objectives: One of the greatest challenges facing the healthcare of the aging population is frailty. There is growing scientific evidence that gait assessment using wearable sensors could be used for prefrailty and frailty screening. The purpose of this study was to examine the ability of a wearable sensor-based assessment of gait to discriminate between frailty levels (robust, prefrail, and frail). Materials and methods: 133 participants (≥60 years) were recruited and frailty was assessed using the Fried criteria. Gait was assessed using wireless inertial sensors attached by straps on the thighs, shins, and feet. Between-group differences in frailty were assessed using analysis of variance. Associations between frailty and gait parameters were assessed using multinomial logistic models with frailty as the dependent variable. We used receiver operating characteristic (ROC) curves to calculate the area under the curve (AUC) to estimate the predictive validity of each parameter. The cut-off values were calculated based on the Youden index. Results: Frailty was identified in 37 (28%) participants, prefrailty in 66 (50%), and no Fried criteria were found in 30 (23%) participants. Gait speed, stance phase time, swing phase time, stride time, double support time, and cadence were able to discriminate frailty from robust, and prefrail from robust. Stride time (AUC = 0.915), stance phase (AUC = 0.923), and cadence (AUC = 0.930) were the most sensitive parameters to separate frail or prefrail from robust. Other gait parameters, such as double support, had poor sensitivity. We determined the value of stride time (1.19 s), stance phase time (0.68 s), and cadence (101 steps/min) to identify individuals with prefrailty or frailty with sufficient sensitivity and specificity. Conclusions: The results of our study show that gait analysis using wearable sensors could discriminate between frailty levels. We were able to identify several gait indicators apart from gait speed that distinguish frail or prefrail from robust with sufficient sensitivity and specificity. If improved and adapted for everyday use, gait assessment technologies could contribute to frailty screening and monitoring.

Prospects of activity limitations among older adults in 23 low and middle income countries

Increasing life expectancy and a growing share of older people around the world spotlight the issue of health during additional years of life. Research on trends of proportions of older people with activity limitations for low and middle income countries is sparse. We use data from the World Health Survey and the UN World Population Prospects to predict prevalence of activity limitations for 23 low and middle income countries for the upcoming 30 years. Our projections highlight huge variation in the proportion of older adults with limitations across investigated countries and this variation is not expected to diminish. However, these countries are facing considerable demographic changes and even though prevalence rates appear almost constant, absolute numbers are changing which require policy interventions. Furthermore, variations across countries reflect not only disparities in health conditions, but also differences in cultural peculiarities of reporting and historical perception of health.

Age, Period, and Cohort Effects on Activities of Daily Living, Physical Performance, and Cognitive Functioning Impairment Among the Oldest-Old in China

BACKGROUND

The aim of this study was to examine the trends in impairment regarding activities of daily living (ADL), physical performance, and cognitive function among the oldest-old (those aged 80 and older) in China between 1998 and 2014.

METHODS

We used data on 34,297 oldest-old individuals from the seven waves of the Chinese Longitudinal Healthy Longevity Study. We estimated age, period, and cohort effects on the prevalence of self-reported ADL impairment, tested physical performance and cognitive function impairment using the age-period-cohort model.

RESULTS

Regarding age, the prevalence of ADL, physical performance, and cognitive function impairment were highest in the centenarians, but they did not increase with age in this population. Among the literate subgroup, the prevalence of cognitive impairment increased more rapidly with age than that in the illiterate subgroup. Regarding period, the prevalence of self-reported and tested physical impairment slowly increased between 1998 and 2014, but cognitive impairment remained stable. Regarding cohort, ADL impairment continuously decreased. However, physical and cognitive impairment remained stable after a brief decline in the early birth cohorts.

CONCLUSIONS

The results suggest that the age effect is still the most obvious effect regarding several types of functional impairment. The likelihood of a younger person experiencing functional impairment may not change significantly, but ADL is likely to be amenable to improvement resulting from improved medical and social care. Therefore, increased care for the oldest-old may considerably improve their quality of life, particularly regarding their basic ADL.

Is there an accurate relationship between simple self-reported functional limitations and the assessment of physical capacity in early old age?

Study design

Observational study.

Objective

To assess the relationship between individual self-reports and measurements of physical condition in early old age.

Background

The use of self-reported questions assessing physical limitations remains questionable in large epidemiological studies. We aimed to test whether there is an accurate relationship between objective measures of physical capabilities and answers given to questions asked of general early old age populations.

Methods

20,335 subjects (45 to 69 years old) performed two gait speed tests at usual and at rapid speeds, and a hand grip strength test. They also completed an interview which included questions about general and specific limitations on their ability to walk one kilometer, climb stairs, and carry 5 kg over a distance of 10 meters. The questions were coded by the patients on a 4-point scale according to the severity of the limitation. Analyses were performed using description of distributions and related tests were carried out.

Results

A fair association was found between individual self-reports and measurements of physical state: limitations on walking one kilometer and climbing stairs were more closely related to rapid than to usual gait speed and to carrying a 5 kg load. For general limitations, the strength of these associations was weaker than the other scores. The association between hand grip strength and the reported score for carrying a mass was better than that for gait speed tests.

Conclusion

Such simple self-assessment questions on physical performance might be useful tools for evaluating functional limitations across a large early old age population in epidemiological research.

Predictive Capacity of Frailty Phenotype Toward Patterns of Disability Identified Using Latent Class Analysis

OBJECTIVES

Frailty phenotype (FP) has low sensitivity toward the identification of older people who will lose 1 or more activities of daily living. Nevertheless, the definition of disability in terms of activities of daily living may not resemble the pattern of functional impairment occurring during aging. The aim of this study was to examine the discriminative capacity of the FP toward the identification of patterns of disabilities in an extended list of tasks, identified among community-dwelling older people.

DESIGN

Longitudinal cohort study.

SETTING AND PARTICIPANTS

We included 997 persons age 65 years and older selected from the Invecchiare in Chianti (InCHIANTI) Study population.

MEASURES

Using latent class analysis, we assessed the pattern of 3-year changes in 24 functional tasks. Then, we calculated the discriminative capacity of the FP for each pattern of disability. Analyses were stratified by sex.

RESULTS

In both men and women, we recognized 3 classes: stable function; disability in complex tasks; and global functional disability. Among women, ability of FP to identify persons in global functional disability showed sensitivity = 0.42, specificity = 0.98, positive and negative predictive values 0.75 and 0.91; the corresponding values for prediction of disability in complex tasks were 0.13, 0.98, 0.68, and 0.75. Similar results were obtained among men.

CONCLUSIONS/IMPLICATIONS

Over 3 years, older people of the InCHIANTI population remained largely functional stable, some persons developed deficiency in complex tasks, and a minority developed global functional disability. Trying to predict these 3 patterns may be useful for the care of older people in order to promote individualized interventions to reduce the burden of disabilities and their consequences. To this purpose, FP showed a fairly good capacity to identify people at risk of functional decline, but further studies are needed to identify instruments with better prognostic capacity.

Exploring Racial and Ethnic Differences in Recovery Maintenance From Mobility Limitation

Objective: This research examines whether racial and ethnic minorities experience less recovery maintenance (i.e., maintaining their recovery status 2 years later). Method: Using Waves 4-12 (1998-2014) of Health and Retirement Study (HRS), this research examines recovery maintenance among a group of older adults who have previously recovered from mobility limitation. Outcomes included newly acquired mobility limitation (reference), recovery maintenance, and death/attrition. Additional analyses examined whether recovery maintenance predicted disability onset. Results: Analyses used multinomial logistic regression to estimate the odds of recovery maintenance 2 years later. After adjusting for socioeconomic status, there were no significant differences in recovery maintenance among older White and minority adults. Recovery maintenance was a robust predictor of subsequent disability onset; there was suggestive evidence that the effect of recovery maintenance on disability onset varied by race. Discussion: This research provides evidence that the higher rates of recovery among minorities is a form of physical resilience.

Wearable Sensors and the Assessment of Frailty among Vulnerable Older Adults: An Observational Cohort Study

Background: The geriatric syndrome of frailty is one of the greatest challenges facing the U.S. aging population. Frailty in older adults is associated with higher adverse outcomes, such as mortality and hospitalization. Identifying precise early indicators of pre-frailty and measures of specific frailty components are of key importance to enable targeted interventions and remediation. We hypothesize that sensor-derived parameters, measured by a pendant accelerometer device in the home setting, are sensitive to identifying pre-frailty. Methods: Using the Fried frailty phenotype criteria, 153 community-dwelling, ambulatory older adults were classified as pre-frail (51%), frail (22%), or non-frail (27%). A pendant sensor was used to monitor the at home physical activity, using a chest acceleration over 48 h. An algorithm was developed to quantify physical activity pattern (PAP), physical activity behavior (PAB), and sleep quality parameters. Statistically significant parameters were selected to discriminate the pre-frail from frail and non-frail adults. Results: The stepping parameters, walking parameters, PAB parameters (sedentary and moderate-to-vigorous activity), and the combined parameters reached and area under the curve of 0.87, 0.85, 0.85, and 0.88, respectively, for identifying pre-frail adults. No sleep parameters discriminated the pre-frail from the rest of the adults. Conclusions: This study demonstrates that a pendant sensor can identify pre-frailty via daily home monitoring. These findings may open new opportunities in order to remotely measure and track frailty via telehealth technologies.

Can we determine whether physical limitations are more prevalent in the US than in countries with comparable life expectancy?

We evaluate the variability in estimates of self-reported physical limitations by age across four nationally representative surveys in the US. We consider its implications for determining whether, as previous literature suggests, the US estimates reveal limitations at an earlier age than in three countries with similar life expectancy: England, Taiwan, and Costa Rica. Based on cross-sectional data from seven population-based surveys, we use local mean smoothing to plot self-reported limitations by age for each of four physical tasks for each survey, stratified by sex. We find substantial variation in the estimates in the US across four nationally-representative surveys. For example, one US survey suggests that American women experience a walking limitation 15 years earlier than their Costa Rican counterparts, while another US survey implies that Americans have a 4-year advantage. Differences in mode of survey may account for higher prevalence of limitations in the one survey that used a self-administered mail-in questionnaire than in the other surveys that used in-person or telephone interviews. Yet, even among US surveys that used the same mode, there is still so much variability in estimates that we cannot conclude whether Americans have better or worse function than their counterparts in the other countries. Seemingly minor differences in question wording and response categories may account for the remaining inconsistency. If minor differences in question wording can result in such extensive variation in the estimates within a given population, then lack of comparability is likely to be an even greater problem when examining results across countries that do not share the same language or culture. Despite the potential utility of self-reported physical function within a survey sample, our findings imply that absolute estimates of population-level prevalence of self-reported physical limitations are unlikely to be strictly comparable across countries—or even across surveys within the same population.

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Self-reported physical limitation estimates vary widely across US national surveys.

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Thus, we cannot determine whether Americans have worse function than others.

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Differences in mode of survey may account for some of the variability.

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Minor differences in question wording and response categories may also play a role.

Air Pollution and Performance-Based Physical Functioning in Dutch Older Adults

BACKGROUND

Functional limitations are a major cause for needing care and institutionalization among older adults. Exposure to air pollution has been suggested to be associated with increased functional limitations in older people.

OBJECTIVE

Our objective was to assess the association between air pollution and physical functioning in Dutch older adults.

METHODS

We analyzed data on performance-based (walking speed, ability to rise from a chair, putting on and taking off a cardigan, balance test) and self-reported physical functioning for 1,762 participants of the Longitudinal Aging Study Amsterdam, who participated in measurement cycles performed in 2005/2006, 2008/2009, and 2011/2012. Annual average outdoor air pollution concentrations [nitrogen dioxide (NO₂), nitrogen oxides (NO_x), particulate matter with diameters ≤2.5μm (PM_2.5), ≤10μm (PM₁₀), and 2.5-10μm (PM_coarse), and PM_2.5 absorbance] at the home address at the start of the first measurement cycle were estimated using land-use regression models. Analyses were performed using mixed models with random participant intercepts adjusting for potential confounders.

RESULTS

Exposure to most air pollutants was associated with reduced performance-based physical functioning; for example, an interquartile range increase in NO₂ exposure was associated with a 0.22 (95% confidence interval: 0.03, 0.42) lower performance test score in fully adjusted models, equivalent to the difference in performance score between participants who differed by 9 mo in age. Exposure to air pollution was generally not statistically significantly associated with self-reported functional limitations, and not associated with a faster decline in performance-based physical functioning over the study period.

CONCLUSION

This study suggests that exposure to air pollution may adversely affect physical performance of older adults in the Netherlands. https://doi.org/10.1289/EHP2239.

Gender Roles and Physical Function in Older Adults: Cross-Sectional Analysis of the International Mobility in Aging Study (IMIAS)

OBJECTIVES

To examine the relationships between physical function and gender-stereotyped traits and whether these relationships are modified by sex or social context.

METHODS

A total of 1995 community-dwelling older adults from the International Mobility in Aging Study (IMIAS) aged 65 to 74 years were recruited in Natal (Brazil), Manizales (Colombia), Tirana (Albania), Kingston (Ontario, Canada), and Saint-Hyacinthe (Quebec, Canada). We performed a cross-sectional analysis. Study outcomes were mobility disability, defined as having difficulty in walking 400 meters without assistance or climbing a flight of stairs without resting, and low physical performance, defined as a score < 8 on the Short Physical Performance Battery. The 12-item Bem Sex Role Inventory (BSRI) was used to classify participants into four gender roles (Masculine, Feminine, Androgynous, and Undifferentiated) using site-specific medians of femininity and masculinity as cut-off points. Poisson regression models were used to estimate prevalence rate ratios (PRR) of mobility disability and poor physical performance according to gender roles.

RESULTS

In models adjusted for sex, marital status, education, income, and research site, when comparing to the androgynous role, we found higher prevalence of mobility disability and poor physical performance among participants endorsing the feminine role (PRR = 1.20, 95% confidence interval (CI) 1.03-1.39 and PRR = 1.37, CI 1.01-1.88, respectively) or the undifferentiated role (PRR = 1.23, 95% CI 1.07-1.42 and PRR = 1.58, CI 1.18-2.12, respectively). Participants classified as masculine did not differ from androgynous participants in prevalence rates of mobility disability or low physical performance. None of the multiplicative interactions by sex and research site were significant.

CONCLUSION

Feminine and undifferentiated gender roles are independent risk factors for mobility disability and low physical performance in older adults. Longitudinal research is needed to assess the mediation pathways through which gender-stereotyped traits influence functional limitations and to investigate the longitudinal nature of these relationships.

Benefits for elders with vulnerable health from the Chronic Disease Self-management Program (CDSMP) at short and longer term

Background

When health declines, older persons may benefit from an intervention program that strengthens their self-management and empowers them to keep in control of their own body and life. Therefore we conducted a Randomized Controlled Trial using the Chronic Disease Self-Management Program (CDSMP) in a sample of 169 older persons in frail health and in need of elderly care.

Methods

We assessed psychological coping resources and wellbeing, pre- and posttreatment and at 6-month follow-up, and investigated whether specific subgroups would benefit in particular from the intervention.

Results

The CDSMP appeared effective with respect to sense of mastery but only in the lower educated participants (p < .05). Furthermore, the intervention stabilized valuation of life in participants, whereas in the controls valuation of life decreased. The high appreciation score and low drop-out are indicative for the applicability of the CDSMP for this specific target group.

Conclusions

We recommend integration of the ingredients of the program into the daily healthcare practice of professionals working with vulnerable older persons. This would involve professional guidance starting from interpersonal equality and emphasising a persons possibilities given their physical or cognitive limitations. This will help older vulnerable persons to focus on their own attainable goals and to experience being successful.

Trial registration

The trial was registered in the Dutch Trial Register as NTR 1173 at 08-03-2008; ‘Is selfmanagement benefical for well-being of average older persons?’ http://www.trialregister.nl/trialreg/admin/rctview.asp?TC=1173

Physical ACtivity facilitation for Elders (PACE): study protocol for a randomised controlled trial

Background

As people live longer, their risk of disability increases. Disability affects quality of life and increases health and social care costs. Preventing or delaying disability is therefore an important objective, and identifying an effective intervention could improve the lives of many older people. Observational and interventional evidence suggests that physical activity may reduce the risk of age-related disability, as assessed by physical performance measures. However it is unclear what approach is the most cost-effective intervention in changing long-term physical activity behaviour in older adults. A new theory-driven behavioural intervention has been developed, with the aim of increasing physical activity in the everyday lives of older adults at risk of disability. This pilot study tests the feasibility and acceptability of delivering this intervention to older adults.

Methods/Design

A randomised controlled trial (RCT) design will be used in the pilot study. Sixty patients aged 65 years and older will be recruited from primary care practices. Patients will be eligible to participate if they are inactive, not disabled at baseline, are at risk of developing disability in the future (Short Physical Performance Battery score <10/12), and have no contraindications to physical activity. Following baseline measures, participants will be randomised in a 2:1 ratio to the intervention or to a control arm and all participants will be followed-up after 6 months. Those randomised to the intervention arm will receive sessions with a trained Physical Activity Facilitator, delivering an intervention based on self-determination theory. Control participants receive a booklet on healthy ageing. The main outcomes of interest are recruitment, adherence, retention and acceptability. Data will also be collected on: self-report and accelerometer-recorded physical activity; physical performance; depression; wellbeing; cognitive function; social support; quality of life, healthcare use, and attitudes to physical activity. A mixed-methods process evaluation will run alongside the RCT.

Discussion

The intervention, if effective, has the potential to reduce disability and improve quality of life in older adults. Before proceeding to a full-scale trial a pilot trial is necessary to ensure intervention feasibility and acceptability, and that the intervention shows evidence of promise.

Trial registration

Current Controlled Trials ISRCTN80470273. Registered 25 October 2013.

Contribution of chronic diseases to the disability burden in a population 15 years and older, Belgium, 1997-2008

Background

Age-associated disability reduces quality of life in older populations and leads to wide-range implications for social and health policy. The identification of diseases that contribute to the disability burden is crucial to the development of prevention and intervention strategies to reduce disability. In this study, we assessed the contribution of chronic diseases to the prevalence of disability in Belgium.

Methods

Data from 35,837 individuals aged 15 years or older who participated in the 1997, 2001, 2004, or 2008 Belgian Health Interview Surveys were used. Disability was defined as difficulties in doing at least one of six activities of daily living (transfer in and out of bed, transfer in and out of chair, dressing, washing hands and face, feeding, and going to the toilet) and/or mobility limitations (ability to walk without stopping less than 200 m). Multiple additive regression models were fitted separately for men and women to estimate the age-specific background disability rate (experienced by everyone, independent of the presence of specific diseases) and disease-specific disability rates (disability rate in subjects who reported selected chronic diseases).

Results

Musculoskeletal, cardiovascular, and respiratory diseases were the main contributors to the disability burden in Belgium. Musculoskeletal diseases were the most prevalent diseases in men and women in all age groups. Neurological diseases and stroke were the most disabling diseases, i.e. caused the highest level of disability among the diseased individuals, in all age groups for men and women, respectively. Back pain was the main cause of disability in men aged 15 to 64 years, while heart attack was the major contributor to the disability prevalence in men aged 65 or older. Likewise, arthritis was the main cause of disability among women across all age groups. Depression was also an important contributor in young subjects (15–54 years). Cancer was not an important contributor to the disability prevalence in Belgium.

Conclusions

To reduce the burden of disability in Belgium, interventions should target musculoskeletal, cardiovascular and respiratory diseases especially among elderly. Furthermore, attention should also be given to depression in young individuals.

Electronic supplementary material

The online version of this article (doi:10.1186/s12889-015-1574-z) contains supplementary material, which is available to authorized users.

A framework for collecting inclusive design data for the UK population

Successful inclusive product design requires knowledge about the capabilities, needs and aspirations of potential users and should cater for the different scenarios in which people will use products, systems and services. This should include: the individual at home; in the workplace; for businesses, and for products in these contexts. It needs to reflect the development of theory, tools and techniques as research moves on. And it must also to draw in wider psychological, social, and economic considerations in order to gain a more accurate understanding of users' interactions with products and technology. However, recent research suggests that although a number of national disability surveys have been carried out, no such knowledge currently exists as information to support the design of products, systems and services for heterogeneous users. This paper outlines the strategy behind specific inclusive design research that is aimed at creating the foundations for measuring inclusion in product designs. A key outcome of this future research will be specifying and operationalising capability, and psychological, social and economic context measures for inclusive design. This paper proposes a framework for capturing such information, describes an early pilot study, and makes recommendations for better practice.

Wearable sensor-based in-home assessment of gait, balance, and physical activity for discrimination of frailty status: baseline results of the Arizona frailty cohort study

BACKGROUND

Frailty is a geriatric syndrome resulting from age-related cumulative decline across multiple physiologic systems, impaired homeostatic reserve, and reduced capacity to resist stress. Based on recent estimates, 10% of community-dwelling older individuals are frail and another 41.6% are prefrail. Frail elders account for the highest health care costs in industrialized nations. Impaired physical function is a major indicator of frailty, and functional performance tests are useful for the identification of frailty. Objective instrumented assessments of physical functioning that are feasible for home frailty screening have not been adequately developed.

OBJECTIVE

To examine the ability of wearable sensor-based in-home assessment of gait, balance, and physical activity (PA) to discriminate between frailty levels (nonfrail, prefrail, and frail).

METHODS

In an observational cross-sectional study, in-home visits were completed in 125 older adults (nonfrail: n=44, prefrail: n=60, frail: n=21) living in Tucson, Ariz., USA, between September 2012 and November 2013. Temporal-spatial gait parameters (speed, stride length, stride time, double support, and variability of stride velocity), postural balance (sway of hip, ankle, and center of mass), and PA (percentage of walking, standing, sitting, and lying; mean duration and variability of single walking, standing, sitting, and lying bouts) were measured in the participant's home using validated wearable sensor technology. Logistic regression was used to assess the most sensitive gait, balance, and PA variables for identifying prefrail participants (vs. nonfrail). Multinomial logistic regression was used to identify variables sensitive to discriminate between three frailty levels.

RESULTS

Gait speed (area under the curve, AUC=0.802), hip sway (AUC=0.734), and steps/day (AUC=0.736) were the most sensitive parameters for the identification of prefrailty. Multinomial regression revealed that stride length (AUC=0.857) and double support (AUC=0.841) were the most sensitive gait parameters for discriminating between three frailty levels. Interestingly, walking bout duration variability was the most sensitive PA parameter for discriminating between three frailty levels (AUC=0.818). No balance parameter discriminated between three frailty levels.

CONCLUSION

Our results indicate that unique parameters derived from objective assessment of gait, balance, and PA are sensitive for the identification of prefrailty and the classification of a subject's frailty level. The present findings highlight the potential of wearable sensor technology for in-home assessment of frailty status.

Wearable sensor-based in-home assessment of gait, balance, and physical activity for discrimination of frailty status: baseline results of the Arizona frailty cohort study

BACKGROUND

Frailty is a geriatric syndrome resulting from age-related cumulative decline across multiple physiologic systems, impaired homeostatic reserve, and reduced capacity to resist stress. Based on recent estimates, 10% of community-dwelling older individuals are frail and another 41.6% are prefrail. Frail elders account for the highest health care costs in industrialized nations. Impaired physical function is a major indicator of frailty, and functional performance tests are useful for the identification of frailty. Objective instrumented assessments of physical functioning that are feasible for home frailty screening have not been adequately developed.

OBJECTIVE

To examine the ability of wearable sensor-based in-home assessment of gait, balance, and physical activity (PA) to discriminate between frailty levels (nonfrail, prefrail, and frail).

METHODS

In an observational cross-sectional study, in-home visits were completed in 125 older adults (nonfrail: n=44, prefrail: n=60, frail: n=21) living in Tucson, Ariz., USA, between September 2012 and November 2013. Temporal-spatial gait parameters (speed, stride length, stride time, double support, and variability of stride velocity), postural balance (sway of hip, ankle, and center of mass), and PA (percentage of walking, standing, sitting, and lying; mean duration and variability of single walking, standing, sitting, and lying bouts) were measured in the participant's home using validated wearable sensor technology. Logistic regression was used to assess the most sensitive gait, balance, and PA variables for identifying prefrail participants (vs. nonfrail). Multinomial logistic regression was used to identify variables sensitive to discriminate between three frailty levels.

RESULTS

Gait speed (area under the curve, AUC=0.802), hip sway (AUC=0.734), and steps/day (AUC=0.736) were the most sensitive parameters for the identification of prefrailty. Multinomial regression revealed that stride length (AUC=0.857) and double support (AUC=0.841) were the most sensitive gait parameters for discriminating between three frailty levels. Interestingly, walking bout duration variability was the most sensitive PA parameter for discriminating between three frailty levels (AUC=0.818). No balance parameter discriminated between three frailty levels.

CONCLUSION

Our results indicate that unique parameters derived from objective assessment of gait, balance, and PA are sensitive for the identification of prefrailty and the classification of a subject's frailty level. The present findings highlight the potential of wearable sensor technology for in-home assessment of frailty status.

Beyond Self-Reports: Changes in Biomarkers as Predictors of Mortality

The proliferation of biosocial surveys has increased the importance of weighing the costs and benefits of adding biomarker collection to population-based surveys. A crucial question is whether biomarkers offer incremental value beyond self-reported measures, which are easier to collect and impose less respondent burden. We use longitudinal data from a nationally representative sample of older Taiwanese (n = 639, aged 54+ in 2000, examined in 2000 and 2006 with mortality follow-up through 2011) to address that question with respect to predicting all-cause mortality. A summary measure of biomarkers improves mortality prediction (as measured by the area under the receiver operating characteristic curve) compared with self-reports alone, but individual biomarkers perform better than the summary score. We find that incorporating change in biomarkers over a six-year period yields a small improvement in mortality prediction compared with one-time measurement. But, is the incremental value worth the costs?

Social class differences in physical functions in middle-aged men and women

OBJECTIVE

The objective of the present study is to analyze gender differences and social class gradients in physical functions; and to study whether the social class gradients in physical functions in midlife differed between men and women.

METHOD

This study used traditionally used physical performance tests and we added several tests of vigorous physical functioning (trunk muscle strength and power and sagittal flexibility). We measured reaction time, one-legged balance, sagittal flexibility, jump height, chair rise ability, trunk muscle- and handgrip strength in 5,412 participants aged 50 to 60 years (68.5% men).

RESULTS

We found gender differences and social class gradients for all physical performance tests. We did not find an interaction between social class and gender, indicating that the social gradient in physical functions did not differ between men and women.

DISCUSSION

Including measures of vigorous physical functioning may add to the existing knowledge on development of functional limitation and poorer functional health later in life.

What do older people understand by mobility-related difficulties?

Despite the centrality of the difficulty concept in the study of disability, there has been little research on its significance from the point of view of people with functional limitations. The main objective of this study was to describe what older people understand when asked about difficulty in undertaking mobility activities. As a secondary objective, we considered whether there are any differences depending on the type of activities, according to the International Classification of Functioning (ICF) mobility domains.

METHODS

Seventeen community-dwelling men and women aged 70 years old or over were interviewed by means of a questionnaire containing 55 items covering the ICF mobility domains. The participants responded to the items while thinking aloud, saying what led them to give a specific answer about their level of difficulty. Inductive content analysis was conducted and categories, subthemes and themes were identified.

RESULTS

Causes of difficulty (pathologies, impairments, symptoms) and accommodations (task modifications and use of aids) were the two themes identified; and their importance (and that of the subthemes included) varied across the types of activity. All the participants said that they had no difficulty in at least one task, despite mentioning changes in the way they performed them.

CONCLUSIONS

Older people's opinions were consistent with theoretical models of disability and with the standard practice of measuring functional limitations by asking about the degree of difficulty; however, the design of these measures needs to be improved in order to detect perceptions of no difficulty in the presence of task modification.

Frailty among rural elderly adults

Background

This study aimed to estimate the prevalence and associated factors related to frailty, by Fried criteria, in the elderly population in a rural area in the Andes Mountains, and to analyze the relationship of these with comorbidity and disability.

Methods

A cross-sectional study was undertaken involving 1878 participants 60 years of age and older. The frailty syndrome was diagnosed based on the Fried criteria (weakness, low speed, low physical activity, exhaustion, and weight loss). Variables were grouped as theoretical domains and, along with other potential confounders, were placed into five categories: (a) demographic and socioeconomic status, (b) health status, (c) self-reported functional status, (d) physical performance-based measures, and (e) psychosocial factors. Chi-square, ANOVA, and multinomial logistic regression analyses were used to test the prognostic value of frailty for the outcomes of interest.

Results

The prevalence of frailty was 12.2%. Factors associated with frailty were age, gender, health status variables that included self-perceived health and number of chronic conditions, functional covariate variables that included disability in activities in daily living (ADL), disabilities in instrumental ADL, chair stand time, and psychosocial variables that included depressive symptoms and cognitive impairment. Higher comorbidity and disability was found in frail elderly people. Only a subset of frail elderly people (10%) reported no disease or disability.

Conclusions

A relevant number of elderly persons living in rural areas in the Andes Mountains are frail. The prevalence of frailty is similar to that reported in other populations in the Latin American region. Our results support the use of modified Cardiovascular Health Study criteria to measure frailty in communities other than urban settings. Frailty in this study was strongly associated with comorbidities, and frailty and comorbidity predicted disability.

Marital status, self-rated health, and mortality: overestimation of health or diminishing protection of marriage?

This study challenges two well-established associations in medical sociology: the beneficial effect of marriage on health and the predictive power of self-rated health on mortality. Using The National Health Interview Survey 1986-2004 with 1986-2006 mortality follow-up (789,096 respondents with 24,095 deaths) and Cox Proportional Hazards Models, we find the protective effect of marriage against mortality decreases with deteriorating health so that the married and unmarried in poor health are at similar risk for death. We also find the power of self-rated health to predict mortality is higher for the married than for any unmarried group. By using ordered logistic regression models, we find thresholds shift such that, compared to the unmarried, the married may not report poorer health until developing more severe health problems. These findings suggest the married tend to overestimate their health status. These two phenomena (diminishing protection and overestimation) contribute to but do not completely explain each other.

Using the Short Physical Performance Battery to screen for frailty in young-old adults with distinct socioeconomic conditions

AIM

To analyze the Short Physical Performance Battery's (SPPB) ability in screening for frailty in community-dwelling young elderly from cities with distinct socioeconomic conditions.

METHODS

Elderly (65-74 years-of-age) from Canada (Saint Bruno; n = 60) and Brazil (Santa Cruz; n = 64) were evaluated with the SPPB to assess physical performance. Frailty was defined as the presence of ≥ 3 of the following criteria: weight loss, exhaustion, weakness, mobility limitation and low physical activity. Linear regression and receiver operating characteristics analyses were carried out.

RESULTS

The SPPB correlated with frailty (R(2) = 0.33), with better results for Saint Bruno. A cut-off of 9 in the SPPB had good sensitivity (92%) and specificity (80%) in discriminating frail from non-frail in Saint Bruno (area under the curve [AUC] = 0.81), but showed fair results in Santa Cruz (AUC = 0.61, sensitivity = 81% and specificity = 52%).

CONCLUSIONS

The SPPB better discriminated frailty in elderly with higher socioeconomic conditions (Saint Bruno).

Asthma in the elderly: Current understanding and future research needs--a report of a National Institute on Aging (NIA) workshop

Asthma in the elderly is underdiagnosed and undertreated, and there is a paucity of knowledge on the subject. The National Institute on Aging convened this workshop to identify what is known and what gaps in knowledge remain and suggest research directions needed to improve the understanding and care of asthma in the elderly. Asthma presenting at an advanced age often has similar clinical and physiologic consequences as seen with younger patients, but comorbid illnesses and the psychosocial effects of aging might affect the diagnosis, clinical presentation, and care of asthma in this population. At least 2 phenotypes exist among elderly patients with asthma; those with longstanding asthma have more severe airflow limitation and less complete reversibility than those with late-onset asthma. Many challenges exist in the recognition and treatment of asthma in the elderly. Furthermore, the pathophysiologic mechanisms of asthma in the elderly are likely to be different from those seen in young asthmatic patients, and these differences might influence the clinical course and outcomes of asthma in this population.

Does self-reported health bias the measurement of health inequalities in U.S. adults? Evidence using anchoring vignettes from the Health and Retirement Study

OBJECTIVES

Measurement of health inequalities based on self-reports may be biased if individuals use response scales in systematically different ways. We use anchoring vignettes to test and adjust for reporting differences by education, race/ethnicity, and gender in self-reported health in 6 domains (pain, sleep, mobility, memory, shortness of breath, and depression).

METHOD

Using data from the 2006 U.S. Health and Retirement Study (HRS) and the 2007 Disability Vignette Survey, we estimated generalized ordered probit models of the respondent's rating of each vignette character's health problem, allowing cut-points to vary by age, gender, education, and race/ethnicity. We then used one-step hierarchical ordered probit (HOPIT) models to jointly estimate the respondent's cut-points from the vignettes and the severity of the respondent's own health problems based on these vignette cut-points.

RESULTS

We found strong evidence of reporting differences by age, gender, education, and race/ethnicity, with the magnitude depending on the specific health domain. Overall, traditional models not accounting for reporting differences underestimated the magnitude of health inequalities by education and race/ethnicity.

DISCUSSION

These results suggest caution in relying on self-reported health measures to quantify and explain health disparities by socioeconomic status and race/ethnicity/ethnicity in the United States. The findings support expansion of the use of anchoring vignettes to properly account for reporting differences in self-reports of health.

Perspectives on use of mobility aids in a diverse population of seniors: implications for intervention

BACKGROUND

Many older adults who might benefit from using mobility aids do not or will not use them. Studies show that attitudes and beliefs strongly affect the decision to use mobility aids. Despite the growing diversity of the population, no prior studies have compared attitudes towards and beliefs about mobility aids by race and ethnicity.

OBJECTIVE

This study aimed to explore whether and how attitudes towards and beliefs about mobility aid use vary by race and ethnicity.

METHODS

We conducted 12 focus groups with 61 community dwelling persons age 65+ years from three groups: White, non-Hispanic Black, and Hispanic. Data were coded and compared across groups.

RESULTS

For all groups, perceived benefits of mobility devices in maintaining independence and control produced positive attitudes. However, the association of mobility aid use with aging and physical decline contributed to stigmatizing attitudes. Black and Hispanic participants expressed apprehension about using unsafe or inappropriate secondhand equipment, heightened concerns about mobility aid users becoming subjects of negative biases, and a preference for fashionable aids. Hispanic participants expressed a preference for human assistance. Participants of all groups perceived physicians as influencing their decisions to use aids.

CONCLUSIONS

Social pressures and perceived stigma deter mobility aid use, particularly in minority populations. Greater physician involvement, positive peer models and affordable, safe, visually appealing devices would promote greater acceptance of mobility aids.

Lower extremity physical performance, self-reported mobility difficulty, and use of compensatory strategies for mobility by elderly women

OBJECTIVE

To describe the relationship between lower extremity physical performance, self-reported mobility difficulty, and self-reported use of compensatory strategies (CSs) for mobility inside the home.

DESIGN

Cross-sectional exploratory study.

SETTING

Community-dwelling elders.

PARTICIPANTS

Disabled, cognitively intact women 65 years or older (N=1002), from the Women's Health and Aging Study I.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

CS scale: no CS, behavioral modifications (BMs) only, durable medical equipment (DME) with or without use of BMs, and any use of human help (HH); and 3 dichotomous CS measures: any CS (vs none); DME+HH (vs BMs only, among users of any CS); any HH (vs DME only, among users of any DME/HH).

RESULTS

Self-reported mobility difficulty and physical performance were significantly correlated with one another (r=-.57, P<.0001) and with the CS scale ([r=.51, P<.001] and [r=-.54, P<.0001], respectively). Sequential logistic regressions showed self-reported difficulty and physical performance were significant independent predictors of each category of CS. For the any CS and DME+HH models, the odds ratio for self-reported difficulty decreased by approximately 50% when physical performance was included in the model, compared with difficulty alone ([18.0 to 8.6] and [7.3 to 3.8], respectively), but both physical performance and difficulty remained significant predictors (P<.0001). The effects of covariates differed for the various CS categories, with some covariates having independent relationships to CS, and others appearing to have moderating or mediating effects on the relationship of self-reported difficulty or physical performance to CS.

CONCLUSIONS

Physical performance, self-reported difficulty, health conditions, and contextual factors have complex effects on the way elders carry out mobility inside the home.

Demographic and socioeconomic status differences in perceptions of difficulty with mobility in late life

OBJECTIVES

This study assesses whether socioeconomic and demographic differences in reported mobility limitations are attributable to differential perceptions of mobility difficulty that result in the differential use of response categories.

METHODS

Data come from the Social Environment and Biomarkers of Aging Study and its parent study, the Taiwan Longitudinal Study of Aging. Ordered probit models with person-specific cut-points are used to test whether, after controlling for underlying mobility using objective performance measures, cut-points for reporting mobility limitations vary across groups defined by demographic and socioeconomic characteristics.

RESULTS

Age is the only characteristic that is consistently associated with the location of the cut-points for reporting mobility difficulty: At the same level of underlying mobility difficulty, older adults are more likely than younger adults are to report difficulty with all tasks except short walks. Other variables showed differences but only for one specific activity, for example, urban residents are more likely to report difficulty running than are rural residents with the same underlying level of mobility function.

DISCUSSION

For most mobility activities, there are no systematic differences in the perception of difficulty by individual characteristics. Thus, for older Taiwanese adults, differences in mobility limitations associated with socioeconomic status are more likely to reflect underlying differences in function than differences in how these groups report the same capacity. The usual loss of mobility with age, however, reflects both a decrease in capacity and a lowering of the threshold for reporting difficulty.

Effect of new disability subtype on 3-year mortality in Chinese older adults

OBJECTIVES

To examine a new method of classifying disability subtypes by combining self-reported and performance-based tools to predict mortality in older Chinese adults.

DESIGN

Prospective cohort study.

SETTING

Community-dwelling older adults.

PARTICIPANTS

Sixteen thousand twenty Chinese adults aged 65 and older from the Chinese Longitudinal Healthy Longevity Survey (CLHLS).

MEASUREMENTS

Self-reported activities of daily living (ADLs) and physical performance (PP) tests (chair standing, lifting a book from floor, turning 360°) cross-classified to create mutually exclusive disability subtypes: subtype 0 (no limitations in PP or ADLs), subtype 1 (limitations in PP, no limitations in ADLs), subtype 2 (no limitations in PP, limitations in ADLs), and subtype 3 (limitations in PP and ADLs). Outcome was mortality over 3 years.

RESULTS

Cox proportional hazard models, controlling for sociodemographic variables, living situation, healthcare access, social support, health status, and life-style, showed that older adults without any limitations in ADLs or PP had significantly lower mortality risk than those with other disability subtypes and that there was a graded pattern of greater mortality according to subtype 1 (hazard ratio (HR)=1.31, 95% confidence interval (CI)=1.20-1.42), 2 (HR=1.39, 95% CI=1.23-1.59), and 3 (HR=1.88, 95% CI=1.72-2.05). When compared with the average survival curve in the cohort, subtypes of isolated performance deficits or self-reported disability did not substantially discriminate risks of death over 3 years.

CONCLUSION

Combined use of self-reported and PP tools is necessary when screening for mutually exclusive disability subtypes that confer significantly higher or lower mortality risks on a population of older adults.

Chronic medical conditions and the sex-based disparity in disability: the Cardiovascular Health Study

BACKGROUND

Older women experience disability more commonly than their male peers. This disparity may be due, in part, to sex-based differences in the prevalence or the disabling effects of common medical conditions. The objectives of this analysis were to (a) quantify the extent to which excess disability in women is explained by higher prevalence of selected medical conditions and (b) evaluate whether the same conditions have differing effects on disability in men and women.

METHODS

We analyzed cross-sectional data from 5,888 community-dwelling older men and women. Disability was defined as difficulty with greater than or equal to one activity of daily living. Thirteen medical conditions were assessed by self-report, testing, or record review.

RESULTS

Controlling for age, race, education, and marital status, women were more likely to experience disability (odds ratio = 1.70, 95% confidence interval = 1.36-2.11). Higher prevalence of arthritis and obesity in women explained 30.2% and 12.9%, respectively, of the sex-based difference in disability rates, whereas male prevalent diseases like vascular conditions and emphysema narrowed the disability gap. Women with arthritis, hearing problems, coronary artery disease, congestive heart failure, stroke, and claudication were more likely to exhibit disability compared with men with the same conditions (p < .001).

CONCLUSIONS

Efforts to lessen sex-based inequality in disability should focus on reducing the prevalence of arthritis and obesity. Future generations may see greater functional disparity if rates of vascular disease and emphysema rise among women. Several conditions were more often associated with disability in women, suggesting additional sex-based differences in the disablement process.

Considering the inclusion of metabolic and cardiovascular markers in the Panel Study of Income Dynamics

The inclusion of biomarkers in social surveys such as the Panel Study of Income Dynamics (PSID) has the potential to answer many elusive questions in social science and public health, including the much-studied relationship between socioeconomic status and health. This article reviews the potential inclusion of biomarkers of cardiovascular and metabolic risk in the PSID. We first discuss the considerable analytical benefits of adding these biomarkers to the PSID, including the exploration of life course hypotheses and the potential to test causal relationships between the social environment and biological systems. Next, we review evidence on the reliability of self-reports of cardiovascular and metabolic risk factors, concluding that the potential bias from relying on self-reports may be substantial. Based on evidence of biological importance as well as practical considerations of ease of in-home collection, our first tier of recommended biomarkers includes measured height, weight, waist and hip circumference, diastolic and systolic blood pressure, resting heart rate, total and high-density lipoprotein (HDL) cholesterol, glycosylated hemoglobin (HbA1c), C-reactive protein (CRP), and cystatin C. Additional markers of secondary priority are also discussed.

Explaining health differences between men and women in later life: a cross-city comparison in Latin America and the Caribbean

This paper describes differences in health and functional status among older men and women and attempts to anchor the explanations for these differences within a lifecourse perspective. Seven health outcomes for men and women 60 years and older from seven Latin American and Caribbean cities are examined, using data from the 2000 SABE survey (Salud, Bienestar y Envejecimiento-n=10,587). Age-adjusted as well as city- and sex-specific prevalence was estimated for poor self-rated health, comorbidity, mobility limitations, cognitive impairment, depressive symptoms and disability in basic and instrumental activities of daily living. Logistic regressions were fitted to determine if the differences between men and women in each outcome could be explained by differential exposures in childhood (hunger, poverty), adulthood (education, occupation) and old age (income) and/or by differential vulnerability of men and women to these exposures. Sao Paulo, Santiago and Mexico, cities in countries with a high level of income inequalities, presented the highest prevalence of disability, functional limitations and poor physical health for both women and men. Women showed poorer health outcomes as compared with men for all health indicators and in all cities. Controlling for lifecourse exposures in childhood, adulthood and old age did not attenuate these differences. Women's unadjusted and adjusted odds of reporting poor self-rated health, cognitive impairment and basic activities of daily living disability were approximately 50% higher than for men, twice as high for number of comorbidities, depressive symptoms and instrumental activities of daily living disability, and almost three times as high for mobility limitations. Higher vulnerability to lifecourse exposures in women as compared with men was not found, meaning that lifecourse exposures have similar odds of poor health outcomes for men and women. A more integrated understanding of how sex and gender act together to influence health and function in old age needs consideration of additional biological and social factors.

Exceptional longevity does not result in excessive levels of disability

Late-life loss of independence in daily living is a central concern for the aging individual and for society. The implications of increased survival to advanced age may be different at the population level than at the individual level. Here we used a longitudinal multi-assessment survey of the entire Danish 1905 cohort from 1998 to 2005 to assess the loss of physical and cognitive independence in the age range of 92 to 100 years. Multiple functional outcomes were studied, including independence, which was defined as being able to perform basic activities of daily living without assistance from other persons and having a MiniMental State Examination (MMSE) score of 23 or higher. In the aggregate, the 1905 cohort had only a modest decline in the proportion of independent individuals at the 4 assessments between age 92 and 100 years: 39%, 36%, 32%, and 33%, with a difference between first and last assessment of 6% [95% confidence interval (CI), -1-14%]. For participants who survived until 2005, however, the prevalence of independence was reduced by more than a factor of 2, from 70% in 1998 to 33% in 2005 (difference, 37%; 95% CI, 28-46%). Similar results were obtained for the other functional outcomes. Analyses of missing data resulting from nonresponse and death suggest that the discrepancy between the population trajectory and the individual trajectory is caused by increased mortality among dependent individuals. For the individual, long life brings an increasing risk of loss of independence. For society, mortality reductions are not expected to result in exceptional levels of disability in cohorts of the very old.

Differential health reporting by education level and its impact on the measurement of health inequalities among older Europeans

BACKGROUND

This study aims to establish whether health reporting differs by education level and, if so, to determine the extent to which this biases the measurement of health inequalities among older Europeans.

METHODS

Data are from the Survey of Health, Ageing and Retirement in Europe (SHARE) covering eight countries. Differential reporting of health by education is identified from ratings of anchoring vignettes that describe fixed health states. Ratings of own health in six domains (mobility, pain, sleep, breathing, emotional health and cognition) are corrected for differences in reporting using an extended ordered probit model. For each country and health domain, we compare the corrected with the uncorrected age-sex standardized high-to-low education rate ratio for the absence of a health problem.

RESULTS

Before correction for reporting differences across the 48 combinations of country by health domain, there was no inequality in health by education (P > 0.05) in 32 of 48 cases. However, there were reporting differences by education (P < 0.05) in 29 out of 48 cases. In general, higher educated older Europeans are more likely to rate a given health state negatively (except for Spain and Sweden). Correcting for these differences generally increases health inequalities (except for Spain and Sweden) and results in the emergence of inequalities in 18 cases (P < 0.05), which may be considered 'statistically significant'. The greatest impact is in Belgium, Germany and The Netherlands, where inequalities (P < 0.05) appear only after adjustment in four of the six health domains.

CONCLUSIONS

These results emphasize the need to account for differences in the reporting of health. Measured health inequalities by education are often underestimated, and even go undetected, if no account is taken of these reporting differences.

Group exercise can improve participants' mobility in an outpatient rehabilitation setting: a randomized controlled trial

Objective: To establish the effects of group exercise on mobility and strength.

Design: Randomized controlled trial.

Setting: Two public hospital outpatient rehabilitation services.

Participants: One hundred and seventy-three people (mean age 74.9 years, SD 10.8) with impaired mobility were randomized and 159 people (92%) completed the trial.

Interventions: Five-week, twice-weekly `circuit-style' group exercise programme run by a physiotherapist (n = 85) and a no-intervention waiting list control group (n = 88).

Main outcome measures: Three aspects of mobility: balance while standing and stepping (Step Test, semi-tandem and tandem stance times); sit-to-stand ability (rate and minimum height) and gait (6-metre and 6-minute walk tests). Lower limb muscle strength (knee flexion and extension).

Results: At retest, exercise participants had improved significantly more than their control counterparts on measures of balance while stepping, sit to stand and gait. Exercise participants averaged 1.6 more steps on the 15-second Step Test (95% confidence interval (CI) 0.5 to 2.8, P=0.005), walked an average of 0.12 m/s faster (95% CI 0.05 to 0.2, P=0.002) and took 2.5 fewer steps in 6 metres (95% CI —4.2 to —0.8, P=0.004). Exercise participants also averaged 0.04 more sit-to-stands/second, (95% CI 0.003 to 0.08, P=0.037) and walked an average of 30.9 metres further in 6 minutes (95% CI 9.4 to 52.4, P=0.005). There were no clinically important or statistically significant between-group differences at retest for the measures of strength (knee extension and flexion), balance while standing or minimal sit-to-stand height.

Conclusion: This short-duration circuit class programme improved mobility, but not strength.

Explaining the effect of gender on functional transitions in older persons

BACKGROUND

Women live longer but experience greater disability than men. The reasons for this gender difference in disability are not well understood.

OBJECTIVE

Our objectives were to determine if the higher prevalence of disability in women is due to greater incidence of disability, longer duration of disability, or both, and to identify factors that potentially explain these gender differences.

METHODS

754 community-living persons aged 70 and older who were non-disabled (required no personal assistance) in four essential activities of daily living (ADLs) were assessed monthly for disability for up to 6 years. A multi-state extension of the proportional hazards model was used to determine the effects of gender on transitions between states of no disability, mild disability, severe disability, and death, and to evaluate potential mediators of these effects.

RESULTS

Women were more likely to make the transition from no disability to mild disability and less likely to make the transitions from mild to no disability and from both mild and severe disability to death. The gender difference in the transitions between no disability and mild disability was largely explained by differences in gait speed and physical activity, but gender difference in transitions to death persisted despite adjustment for multiple potential mediators.

CONCLUSION

The higher prevalence of disability in women versus men is due to a combination of higher incidence and longer duration, resulting from lower rates of recovery and mortality among disabled women.

Physical activity in middle-aged adults reduces risks of functional impairment independent of its effect on weight

OBJECTIVES

To assess the association between physical activity and subsequent physical functioning in middle-aged adults across a range of body mass index (BMI) categories.

DESIGN

Prospective nationally representative cohort studies.

SETTING

The United States and England.

PARTICIPANTS

Eight thousand seven hundred two individuals in the United States and 1,507 in England aged 50 to 69 and free of impairment at baseline, followed up for 6 years.

MEASUREMENTS

Self-reported and measured BMI and self-reported level of physical activity. Outcome measures were score on a physical performance battery and self-reported mobility impairment.

RESULTS

In both studies, being overweight and being obese were associated with greater risk of impairment (than being of recommended weight). In all weight categories and both countries, higher levels of physical activity were associated with lower risks of mobility impairment. For example, U.S. respondents of recommended weight (BMI 20-25) who were active on 3 or more days per week had a relative risk (RR) of incident mobility difficulties, compared with those who were less active, of 0.56 (95% confidence interval (CI)=0.40-0.78); for those who were obese (BMI >/=30) the corresponding RR was 0.59 (95% CI=0.45-0.76).

CONCLUSION

Excess bodyweight is a risk factor for impaired physical function in middle-aged and older people. Physical activity is protective of impaired physical functioning in this age group in subjects with recommended weight, overweight, and obesity. Older adults should be encouraged to engage in appropriate levels of physical activity irrespective of their weight.

Health-related fitness tests as predictors of difficulties in long-distance walking among high-functioning older adults

BACKGROUND AND AIMS

Health-related fitness (HRF) tests are valid predictors of self-reported mobility difficulties among high-functioning older adults. The aim of the present study was to identify optimal cut-off values for HRF tests predicting self-reported difficulties in walking 2 km (WD).

METHODS

Subjects were 55- to 69-year-old men and women who were free of WD at baseline. The HRF assessment in 1996 included seven test items, and postal questionnaires were used to assess occurrence of new WD in 2002. Analysis of covariance and receiver-operating characteristic analysis were used as statistical methods.

RESULTS

In a 1-km walk, the sensitivity and specificity at the optimal cut-off 10:15 (min:s) for men were 63% and 75%, and at the cut-off 10:47 for women 70% and 71%. In dynamic back extension, the sensitivity and specificity at the optimal cut-off 16.5 (repetitions) were 67% and 65% in men and 82% and 59% at cut-off 13.5 in women. Correspondingly, in backward walking, the sensitivity and specificity at the optimal cut-off 27.7 (seconds) were 65% and 69% in men and 74% and 61% at cutoff 35.0 in women.

CONCLUSIONS

The 1-km walk, dynamic back extension and backward walking tests had the best predictive value for WD. These tests, with identified cut-off values, can be used to screen individuals who are at increased risk of WD. Tests can also be used in physical activity counseling to target activity to those components of HRF that indicate poor fitness and are important for good walking ability.

Does the predictive power of self-rated health for subsequent mortality risk vary by socioeconomic status in the US?

BACKGROUND

The purpose of this study is to test whether the predictive power of an individual's self-rated health (SRH) on subsequent mortality risk differs by socioeconomic status (SES) in the United States.

METHODS

We use the National Health Interview Survey 1986-94 linked to Multiple Cause of Death Files 1986-97 (NHIS-MCD). Analyses are based on non-Hispanic Black and White adults 25 and older (n = 358,388). Cox proportional hazard models are used to estimate the effect of SRH on mortality risk during follow-up. Interactions of SRH and level of education and SRH and level of income are used to assess differences in the predictive power of SRH for subsequent mortality risk.

RESULTS

The effect of SRH on subsequent mortality risk differs by level of education and level of income. Lower health ratings are more strongly associated with mortality for adults with higher education and/or higher income relative to their lower SES counterparts.

CONCLUSIONS

Our findings suggest that individuals with different education or income levels may evaluate their health differently with respect to the traditional five-point SRH scale, and hence their subjective health ratings may not be directly comparable. These results have important implications for research that tries to quantify and explain socioeconomic inequalities in health based on self-rated health.

Multidimensional evaluation of home-dwelling elderly: The impact of medical and social factors on health status indices

Since 1980 the WHO has proposed at least tree indices to characterize health status (impairment, disease, disability). Their relationships have been examined in some chronic diseases, but little is known about elderly at risk of frailty. We studied the influence of gender, age and living conditions on these indices and on their relationships. A sample of 100 home-dwelling elderly subjects underwent a multidimensional assessment at home to collect biological, symptomatic and functional measures. The sample consists of 48 males and 47 females, their mean age was 80.2 years, the mean schooling was 4.7 years. Living at home alone 14%, with spouse 60%, other 26%. Applying a MANOVA that considered the above mentioned items as factors and the biological, symptomatic and functional measures as dependent variables, no significant difference was found in biological measures, whereas the interaction of (i) gender and living conditions, (ii) gender and age classes showed differences in affective symptoms. Moreover, gender alone resulted a significant source of differences in instrumental activities of daily living (IADL). To assay the impact of biological, symptomatic scores on disability, a backward linear regression was applied. The principal index of postural control, Tinetti scale score, alone explained 50% of variance in activities of daily living (ADL), this index together with the measures, respectively, of cognitive functioning (Camcog score) and behavioral profile neuro-psychological inventory (NPI) score resulted to be the main sources of the IADL variance. These preliminary data allow us to identify both medical and social factors able to enhance the risk of frailty; is worth wile to stress that prevention programs could be targeted on possible modification of these factors.