Women's Health And Aging Study Research Articles

Frailty in older breast cancer survivors: age, prevalence, and associated factors.

To describe frailty and associated factors in breast cancer survivors (BCSs) and evaluate whether BCSs are frail at an earlier age than female participants from in two large epidemiological studies. Descriptive, cross-sectional. School of Nursing at Oregon Health and Science University. 216 BCSs aged 53-87 years who were a mean 5-7 years post-treatment and not currently participating in exercise. Performance tests, clinical measures, and self-reported questionnaires provided baseline data on five criteria for frailty. Frailty was defined as meeting three of the five criteria of the frailty phenotype: shrinking, exhaustion, low activity, slowness, and weakness. Data were compared to published data from women in the Cardiovascular Health Study (CHS) and Women's Health and Aging Study (WHAS). Eighteen percent of BCSs aged 70-79 years were frail compared to 11% of women of the same age in the CHS and WHAS. Frailty was more common at a younger age in BCSs, and more BCSs were frail in all age groups compared to women in the CHS study until about age 80 years, when prevalence of frailty was similar in the two groups. Fifty percent of BCSs were classified as prefrail because they met one or two of the five frailty criteria. Higher body mass index increased the odds of frailty, and higher physical activity decreased the odds of frailty (odds ratio [OR] = 1.12, p = 0.003, and OR = 0.99, p = 0.000, respectively). Frailty and prefrailty may be common in BCSs and may occur at an earlier age than in adults without a history of breast cancer. Nurses should be alert to prefrailty or frailty at a younger age in BCSs. Awareness and early intervention may delay or prevent frailty. BCSs may be frail even when they are not yet considered older adults. Prefrailty in BCSs is important to recognize because it suggests impending frailty that could lead to reduced physical functioning or poor health. Prefrailty and frailty could be assessed in BCSs aged 50 years and older in a clinical setting using a few questions about weight, fatigue, and activity levels, in addition to simple tests of walking speed and grip strength, if warranted.

Serum ceramides predict incident Alzheimer's disease: The women's health and aging study (WHAS) II

Serum ceramides predict incident Alzheimer's disease: The women's health and aging study (WHAS) II

Surrogate screening models for the low physical activity criterion of frailty

Low physical activity, one of five criteria in a validated clinical phenotype of frailty, is assessed by a standardized, semiquantitative questionnaire on up to 20 leisure time activities. Because of the time demanded to collect the interview data, it has been challenging to translate to studies other than the Cardiovascular Health Study (CHS), for which it was developed. Considering subsets of activities, we identified and evaluated streamlined surrogate assessment methods and compared them to one implemented in the Women's Health and Aging Study (WHAS). Using data on men and women ages 65 and older from the CHS, we applied logistic regression models to rank activities by "relative influence" in predicting low physical activity.We considered subsets of the most influential activities as inputs to potential surrogate models (logistic regressions). We evaluated predictive accuracy and predictive validity using the area under receiver operating characteristic curves and assessed criterion validity using proportional hazards models relating frailty status (defined using the surrogate) to mortality. Walking for exercise and moderately strenuous household chores were highly influential for both genders. Women required fewer activities than men for accurate classification. The WHAS model (8 CHS activities) was an effective surrogate, but a surrogate using 6 activities (walking, chores, gardening, general exercise, mowing and golfing) was also highly predictive. We recommend a 6 activity questionnaire to assess physical activity for men and women. If efficiency is essential and the study involves only women, fewer activities can be included.

Severe osteopenia and osteoporosis, sarcopenia, and frailty status in community-dwelling older women: Results from the Women's Health and Aging Study (WHAS) II

ObjectivesThe goal of this study was to examine the associations between severe osteopenia and osteoporosis and/or sarcopenia on frailty status, a major geriatric syndrome in community-dwelling older women. DesignCross-sectional analysis. SettingWomen's Health and Aging Studies II (WHAS-II), Baltimore, Maryland. Participants and measurementsThe analytic sample for this study included 250 women aged 76–86years old who underwent DXA evaluation at round 4. Frailty was determined using validated screening criteria. Severe osteopenia was defined as BMD between −2.0 SD and −2.49 SD and osteoporosis as BMD less than −2.5 SD (lumbar spine and/or proximal femur). Sarcopenia was determined by the appendicular lean mass by height2 (aLM/ht2 method) and considered present when the value was less then −2 SD compared to young women. ResultsMean age of study subjects was 79.6 (±2.7) years. Overall prevalence of frailty was 6.8% (n=17). Severe osteopenia/osteoporosis occurred in 42.1% (n=7) in the frail group, 28% (n=33) in the pre frail group and 25.2% in the robust group. Sarcopenia was present in 52.9% (n=9) in the frail group, 42% (n=50) in the pre frail and 41.2% (n=47) in the robust group. Almost sixteen percent (n=39) had severe osteopenia/osteoporosis concomitant to sarcopenia. In an adjusted logistic regression model, severe osteopenia/osteoporosis (OR: 2.1; 95% CI: 0.68–6.6, p=0.196) and sarcopenia (OR: 3.1; 95% CI: 0.88–11.1; p=0.077) were individually associated with frailty, though not statistically significant. On the other hand, the likelihood of being frail was substantially higher in the presence of these two syndromes (OR: 6.4; 95% CI: 1.1–36.8, p=0.037). ConclusionThese findings suggest a concomitant impact of severe osteopenia/osteoporosis plus sarcopenia in regard to frailty status in a sample of oldest old women living in the community.

A genome-wide association analysis of serum iron concentrations

AbstractTo investigate genetic variants that affect iron concentrations in persons not affected by overt genetic disorders of iron metabolism, a genome-wide association study was conducted in the InCHIANTI Study (N = 1206) and the Baltimore Longitudinal Study of Aging (N = 713). The top 2 single-nucleotide polymorphisms were examined for replication in the Women's Health and Aging Study (WHAS) I and II (N = 569). The single-nucleotide polymorphism most strongly associated with lower serum iron concentration was rs4820268 (P = 5.12 × 10−9), located in exon 13 of the transmembrane protease serine 6 (TMPRSS6) gene, an enzyme that promotes iron absorption and recycling by inhibiting hepcidin antimicrobial peptide transcription. The allele associated with lower iron concentrations was also associated with lower hemoglobin levels, smaller red cells, and more variability in red cell size (high red blood cell distribution width). Our results confirm the association of TMPRSS6 variants with iron level and provide further evidence of association with other anemia-related phenotypes.

Executive Decline and Dysfunction Precedes Declines in Memory: The Women's Health and Aging Study II

Understanding preclinical transitions to impairment in cognitive abilities associated with risks for functional difficulty and dementia. This study characterized in the Women's Health and Aging Study (WHAS) II 9-year declines and transitions to impairment across domains of cognition. The WHAS II is an observational study of initially high-functioning, community-dwelling women aged 70-80 years at baseline. Random-effects models jointly compared rates of decline, and discrete-time Cox models estimated hierarchies of incident clinical impairment on measures of psychomotor speed and executive function (EF) using the Trail Making Test and in immediate and delayed verbal recall using the Hopkins Verbal Learning Test. Patterns of transition were related to incidence of global cognitive impairment on the Mini-Mental State Exam (MMSE). Mean decline and impairment occurred first in EF and preceded declines in memory by about 3 years. Thereafter, memory decline was equivalent to that for EF. Over 9 years, 49% developed domain-specific impairments. Risk of incident EF impairment occurred in 37% of the sample and was often the first impairment observed (23.7%), at triple the rate for psychomotor speed (p < .01). Risk of immediate and delayed recall impairments was nearly double that for psychomotor speed (p values <.01). Incident impairment in EF and delayed recall was associated with greater risk for MMSE impairment. Executive dysfunction developed first among nearly one quarter of older women and was associated with elevated risk for global cognitive impairment. Because EF declines preceded memory declines and are important to efficient storage and retrieval EF represents an important target for interventions to prevent declines in memory and MMSE both of which are associated with progression to dementia.

Oxidative protein damage is associated with poor grip strength among older women living in the community

Grip strength, an indicator of muscle strength, has been shown to be a predictor of poor outcomes among older adults. Protein carbonylation, an indicator of oxidative damage to proteins, leads to cellular dysfunction and a decline in tissue function. Oxidative stress has been implicated in the pathogenesis of sarcopenia. The objective was to determine whether serum protein carbonyl concentrations are associated with grip strength in older women living in the community. A cross-sectional study was conducted in 672 women, aged 65 and older, from the Women's Health and Aging Study (WHAS) I, the one-third most disabled women residing in the community in Baltimore, MD. Protein carbonyl and grip strength were measured in each patient. In a multivariate analysis adjusting for age, race, body mass index, and Mini-Mental Status Examination score, protein carbonyls (nmol/mg) were associated with grip strength (β = −6.77, P < 0.01). The statistical association was unchanged after the analysis adjusted for hypertension, congestive heart failure, and depression. Ordered logistic regression models adjusted for the above factors showed that protein carbonyls are associated with increased odds of being in the lower quartiles of grip strength (odds ratio 8.74, 95% confidence interval 1.06–71.89, P = 0.043). These results suggest oxidative protein damage is independently associated with low grip strength among older women living in the community. Increased oxidative stress may be contributing to loss of muscle strength in older adults.

Oxidative protein damage is associated with poor grip strength among older women living in the community

Grip strength, an indicator of muscle strength, has been shown to be a predictor of poor outcomes among older adults. Protein carbonylation, an indicator of oxidative damage to proteins, leads to cellular dysfunction and a decline in tissue function. Oxidative stress has been implicated in the pathogenesis of sarcopenia. The objective was to determine whether serum protein carbonyl concentrations are associated with grip strength in older women living in the community. A cross-sectional study was conducted in 672 women, aged 65 and older, from the Women's Health and Aging Study (WHAS) I, the one-third most disabled women residing in the community in Baltimore, MD. Protein carbonyl and grip strength were measured in each patient. In a multivariate analysis adjusting for age, race, body mass index, and Mini-Mental Status Examination score, protein carbonyls (nmol/mg) were associated with grip strength (beta = -6.77, P < 0.01). The statistical association was unchanged after the analysis adjusted for hypertension, congestive heart failure, and depression. Ordered logistic regression models adjusted for the above factors showed that protein carbonyls are associated with increased odds of being in the lower quartiles of grip strength (odds ratio 8.74, 95% confidence interval 1.06-71.89, P = 0.043). These results suggest oxidative protein damage is independently associated with low grip strength among older women living in the community. Increased oxidative stress may be contributing to loss of muscle strength in older adults.

Association Between Mild Anemia and Executive Function Impairment in Community‐Dwelling Older Women: The Women's Health and Aging Study II

To evaluate the relationship between mild anemia and executive function in community-dwelling older women. Cross-sectional. Community-based. High-functioning subjects participating in the baseline assessment of the Women's Health and Aging Study (WHAS) II, Baltimore, Maryland, 1994 to 1996. WHAS II eligibility criteria included aged 70 to 80, a Mini-Mental State Examination score of 24 or greater, and absence of advanced disability (difficulty in no more than 1 domain of physical function). Included in this study were 364 subjects with a hemoglobin concentration 10 g/dL or greater and known executive function status. Trail Making Test (TMT) Parts B and A. Tertiles of time to complete each test were used to define best (bottom), intermediate, and worst (top) performance. Tertiles of the difference TMT-B minus TMT-A were calculated. Anemia defined as hemoglobin concentration less than 12 g/dL. The percentage of subjects in the worst TMT-B, TMT-A, and TMT-B minus TMT-A performance tertile was highest for those with anemia. Prevalent anemia substantially increased the likelihood of performing worst (as opposed to best) on the TMT-B (odds ratio (OR) = 5.2, 95% confidence interval (CI) = 1.3-20.5), TMT-A (OR = 4.8, 95% CI = 1.5-15.6), and TMT-B minus TMT-A (OR = 4.2, 95% CI = 1.0-17.2), even after controlling for age, education, race, prevalent diseases, and relevant physiological and functional parameters. This study provides preliminary evidence in support of the hypothesis that mild anemia might be an independent risk factor for executive function impairment in community-dwelling older adults. Whether such an association is causal or noncausal remains to be determined.

RESPONSE LETTER TO DR. GAYNES

To the Editor: We thank Dr. Gaynes for taking interest in our study to understand the role of vision in one's ability to take medications. We agree that taking medications is a complex instrumental activity of daily living (IADL) that likely relies on components of vision. The major, and largely unsubstantiated, premises of Dr. Gaynes' letter, that the Hopkins Medication Schedule (HMS) did not adequately measure ability and that vision was poorly measured, expose fundamental misunderstandings regarding (1) the import of the HMS and its application here and (2) vision assessments and interpretation. Regarding the former, Dr. Gaynes fails to distinguish between ability and adherence, further reinforcing the importance of methods that differentiate these. We refer him to the HMS validation paper1 to understand the import of developing a standard, objective measure of one's ability to understand and implement a medication prescription, independent of other determinants of adherence. Medication-taking ability was assessed using an ecologically valid, standardized instrument that mimics the commonly used medication organizer with a simple medication regimen. The HMS-based measure of ability incorporates correctness and speed of task completion, as do many measures of functional or IADL ability; faster was not assumed to be better. With regard to vision assessments, we are confident in the standardized, validated methods developed by vision experts and employed in the Women's Health and Aging Study (WHAS) II.2-4 Although near acuity was not evaluated, it is well known that distance and near acuities are correlated,5, 6 and the observed association between distance acuity and ability remains an important finding. Nevertheless, we agree that the association with near visual acuity may be informative. We disagree with Dr. Gaynes' statement that a modified Pelli-Robson contrast at closer distance would have been more meaningful. Test distance over the range in question does not affect Pelli-Robson contrast sensitivity.7 The Mars Letter Contrast Sensitivity he recommended was not available at the time of WHAS II, but a recently published validation showed excellent agreement between Mars and Pelli-Robson contrast sensitivities.8 Dr. Gaynes' statements regarding stereopsis were based on a study of young participants (mean ages 29, vs 77 in WHAS II) with normal stereoacuity (mean 17.6 vs 100 seconds of arc);9 those findings should not be generalized to older persons with impaired stereoacuity. In older adults, stereopsis has been associated with activity of daily living disability and function.10, 11 Regarding dexterity and “alertness,” as we described, testers assisted participants opening containers, thus limiting contamination by dexterity problems. Adjusting for hand osteoarthritis did not substantially change our findings. A previous study suggesting that vision might facilitate adaptations to age-related functional and cognitive declines12 was the impetus for including interactions between vision and cognition. In summary, Dr. Gaynes' comments extend our line of inquiry by positing that the significance of near visual acuity to medication taking should be measured. We welcome a formal test of this hypothesis, because this is the means by which scientific advances are made and translated into clinical practice for maintenance of independent function. Financial Disclosures: The research referred to in this article was supported by National Institute on Aging Grant R01 AG11703–01A1 and by National Institutes of Health (NIH)—National Center for Research Resources, Outpatient General Clinical Research Center Grant RR00722. Dr. Griswold and Dr.Windham were supported by the NIH T-32 Training Grant entitled “The Epidemiology and Biostatistics of Aging” when this study was conducted. Author Contributions: Windham: study concept and design, data analysis and interpretation, manuscript preparation, letter to editor draft and revision. Griswold: study design, data analysis and interpretation, manuscript preparation, letter to editor revision. Fried: WHAS II principle investigator, study concept and design, acquisition of subjects, data interpretation, manuscript editing, letter to editor revision. Rubin: study design, data interpretation, manuscript editing, letter to editor revision. Xue: data interpretation, manuscript editing. Carlson: study concept and design, data interpretation, manuscript editing, letter to editor revision. Sponsor's Role: None.

Association of Mild Anemia and Executive Cognitive Function Impairment in High Functioning Community-Dwelling Older Women.

Background: Anemia in the elderly is common and may be associated with atypical clinical presentations. Although the impact of severe anemia on cognition has been studied in patients with cancer, less is known about the association of mild anemia on cognitive function in the elderly. Executive cognitive functioning (ECF) refers to the execution of complex activities that involve a set of higher-order cognitive abilities primarily dependent on the frontal lobes. ECF plays a major role in the maintenance of the functional status of older adults. Knowledge about potentially modifiable risk factors for ECF impairment in older adults is limited. The goal of this study was to test the hypothesis that mild anemia is associated with ECF impairment in high functioning, community-dwelling older women.Methods: Cross-sectional analysis of baseline data from the Women's Health and Aging Study (WHAS) II, 1994–1996, Baltimore, MD. WHAS II is a population-based study of 436 cognitively intact (Mini-Mental State Exam >24) and highly physically functioning women aged 70–80 years. The analytic sample included 364 subjects with Hb >10 g/dL and the following ECF test components: Trail Making Tests part B (TMTB) - primary outcome - and part A (TMTA), and the difference TMTB-TMTA. Multivariate polytomous logistic regression models were used to model the relationship between performance (based on tertiles) on each ECF test as a function of Hb, while controlling for age, education, cardiovascular disease, and a number of other potential confounders, such as hypertension, diabetes, depressive symptoms, calculated creatinine clearance, forced expiratory volume in the first second, thyroid stimulating hormone, total cholesterol levels, body mass index, walking speed, and prevalent mobility difficulty.Results: Subjects with mild anemia (Hb 10–12 g/dL) performed worst in all ECF tests; i.e., the percentage of subjects in the best performance tertile for each test was lowest for those with Hb within 10–12 g/dL. Estimates from multivariate models revealed that, as compared to those with Hb≥12 g/dL, those with Hb within 10–12 g/dL were substantially less likely to be in the best performance tertile of the TMTB [odds ratio (OR).23, 95% confidence interval (CI):.06–.86; p=.029], TMTA (OR.27, 95%CI:.07–.98; p=.047), and TMTB-TMTA (OR.30, 95%CI:.10–.89; p=.031), even after comprehensive adjustment.Conclusion: In this cross-sectional study, mild anemia was an independent risk factor for prevalent ECF impairment in high functioning community-dwelling older women. This raises the hypothesis that correction of mild anemia could potentially provide an opportunity for prevention of cognitive and functional decline in older adults. To test this hypothesis, prospective observational studies and clinical trials are warranted.

The Effects of Widowhood on Disabled Older Women (The Women's Health and Aging Study)

This study examined the effects of becoming widowed for older women with pre-existing physical disability. Data from three consecutive interviews from the Women's Health and Aging Study (WHAS) were used to compare depression, quality of life, and functional difficulty for widowed and non-widowed women. The two groups of 24 women were matched by age, disability level, domains of disability, and race. Repeated measures of analyses of variance (ANOVAs) revealed that, for both groups, depression scores were low and remained relatively stable and they were satisfied with their quality of life at all three time points (T1 = 0–6 months pre-bereavement, T2 = 0–6 months bereaved, T3 = 6–12 months bereaved), with no significant group by time interaction effects. The two groups were no different on their levels of functional difficulty at T1 and T2 but by T3, surprisingly, the widows reported slightly less difficulty. Overall, the findings show that disabled women who became widows demonstrate a noticeable degree of resiliency and hardiness.

Short-term change in physical function and disability: the Women's Health and Aging Study.

Although measures of physical function are predictive of future disability, little is known about the short-term impact of changes in physical function on disability. Data from 93 of the 102 women who participated in the Weekly Substudy of the Women's Health and Aging Study (WHAS) were used to explore the association of changes in physical function with disability. The WHAS Substudy included 24 weekly assessments of three standard performance tests and self-reported disability in activities of daily living (ADLs) and basic mobility. Using random-effects models, we found small but significant (ps <.01) changes in ADL and mobility disability during weekly follow-up. Baseline performance scores were significantly associated with both ADL and mobility disability (ps <.001), accounting for 27% and 36% of the between-person variability in each type of disability, respectively. After adjustment for baseline scores, change in performance scores was significantly associated with ADL disability (beta = 0.08, p <.01) and mobility disability (beta = 0.12, p <.001), but accounted only for a small proportion (<10%) of the variability in the rate of change in disability outcomes. There was no evidence for an additional effect on either type of disability because of having a single episode of a higher or lower than usual performance score, or because of periods of at least 4 consecutive higher or lower than usual performance test scores. Basic physical functions account for a substantial proportion of the heterogeneity in ADL and mobility disability among older disabled women, but have a relatively small impact on short-term changes in either type of disability. Effective prevention of disability may require attention to a wider array of risk factors than just limitations in basic physical functions.

Change in physical performance over time in older women: the Women's Health and Aging Study.

Although lower and upper extremity performance measures are widely used and represent validated physical function measures in older adults, there is limited information regarding the magnitude of changes in these measures over time. This study (i) assesses prospective changes in physical performance measures, (ii) defines a summary score that demonstrates a significant amount of change over time, and (iii) examines rates of decline according to age and baseline performance levels. Data from the Women's Health and Aging Study (WHAS) were analyzed to assess change in the one third most disabled older women living in the community. Lower extremity function was assessed using walking speed, balance, and chair stands tests. The putting-on-blouse test, the lock and key test, the Purdue Pegboard test, and grip strength were used to gauge upper extremity function. Continuous and categorical summary performance scores were calculated using continuous and categorical data of lower and upper performance measures. After 3 years, lower extremity performance measures declined by 16%-27%, while upper extremity performance measures declined less (7%-24%). For lower extremity function, the continuous summary performance score showed a slightly greater 3-year decline from baseline (decline vs baseline mean: 23%; decline vs SD of the baseline mean: 59%) than the categorical score (22% and 41%, respectively). Older age and intermediate level of baseline performance were associated with the greatest decline, especially for lower extremity function. In moderately to severely disabled women aged 65 or older, lower extremity measures show more change over 3 years than upper extremity measures. Among the lower extremity summary scores, the continuous score changes more over time than the categorical score with respect to the baseline SD. The lower extremity continuous summary performance score may be a useful outcome measure for clinical studies of physical performance in older women.

Designing a Community Study of Moderately to Severely Disabled Older Women: The Women's Health and Aging Study

PURPOSE: This paper reports on the design of a community-based study focusing on the effects of prevalent and incident disease and other modifying influences, on changes in functioning among moderately and severely disabled elderly women over a 3-year period [the Women's Health and Aging Study (WHAS)]. METHODS: An approach to conceptualizing and assessing disability which captured functional difficulty across a broad range of activities and tasks was developed, tested on existing national data, and used, in the form of a brief screening instrument, to identify moderately to severely disabled elderly women in a large community sample representative of women 65 and older. Women meeting study criteria were recruited for a baseline interview, a 3-hour in-home clinical exam, as well as follow-up interviews and physical performance tests at 6-month intervals for three years. RESULTS: Prevalence of moderate to severe disability among the screened population proved similar to that expected from analysis of national data (about one-third). The screening interview response rate was 78%, and 71% of women eligible by disability criteria participated. Only women completing both the baseline interview and clinical exam were counted as respondents. Analysis of characteristics of participants and nonparticipants indicated no selection bias related to levels of disability. However, education, race, and age were associated with participation. Women with some college education, black women, and younger women were more likely to participate. CONCLUSIONS: The approach used to identify and recruit moderately to severely disabled elderly women in the WHAS is both feasible and applicable to other community-based research where inclusion of elderly people with moderate to severe disability across several areas of functioning is an objective. Other aspects of study design, such as use of proxy respondents, will also affect recruitment of individuals with impaired functioning into epidemiologic studies.

Association between executive attention and physical functional performance in community-dwelling older women.

Executive functions supervise the contents of working memory, where information from long-term memory is integrated with information in the immediate present. This study examined whether executive attentional abilities were uniquely associated with the performance of complex, instrumental activities of daily living (IADLs) in cognitively intact and physically high-functioning older women. Participants were 406 community-residing, older women aged 70-80 years in the Women's Health and Aging Study (WHAS) II, screened to be physically high functioning and cognitively intact using the Mini-Mental State Exam. Hierarchical regression models, adjusted for demographic and disease variables, were used to evaluate the association of cognitive domains, including executive attention, memory, psychomotor speed, and spatial ability with summary measures of IADL (e.g., looking up and dialing a telephone number) and mobility-based ADL (e.g., walking 4 meters) function. Tests of executive attention were associated with performance on IADLs (6.6%) and, to a lesser degree, mobility-based ADLs (1%), adjusting for demographic and disease variables. In particular, the mental flexibility component of the Trail Making Test accounted for the majority of attentional variance in IADL performance. Older age, lower education, and African American race were also associated with poorer physical test performances. Executive difficulties in flexibly planning and initiating a course of action were selectively associated with slower performance of higher-order IADL tests, relative to other domains of cognition, in a high-functioning, community-based older cohort. These results suggest that executive functions may be important in mediating the onset and progression of physical functional declines.

Coimpairments: strength and balance as predictors of severe walking disability.

Little information is available on the joint effects of multiple impairments (coimpairments) on the risk of disability. Our aim was to study the joint effects of strength and balance impairments on severe walking disability. The data are from the baseline of the Women's Health and Aging Study (WHAS), a study of moderately to severely disabled women. A total of 1,002 women aged 65 and older participated in the tests, which took place in their homes. Severe walking disability was defined as self-reported inability to walk one-quarter mile and customary walking speed in a 4-meter test of < or =0.4 m/s. Balance was measured as an ability to hold progressively more difficult stands (feet side-by-side, semitandem and tandem stands). Maximal knee extension strength was measured using a hand-held dynamometer. There were 129 women who were severely walking disabled but able to walk at least minimally. In logistic regression analysis, balance and knee extension strength were independent predictors of severe walking disability. To study the combined effects, nine groups were formed on the basis of strength tertiles by balance categories in the entire population. In the best balance category, the crude prevalences of severe walking disability were 1.2%, 4.9%, and 14.3% in the highest to lowest strength tertiles. In the middle balance category, the rates were 2.9%, 10.0%, and 45.4.1%, and in the poorest balance category 4.9%, 22.1%, and 42.6%, correspondingly. The age, body weight, and height-adjusted odds ratios (OR) showed that the risk of severe walking disability in the subgroup with best balance and strength was less than 5% of the risk in the subgroup with poorest balance and strength (OR .034, 95% confidence interval [CI] .007-.166). Correspondingly, in the subgroups with poorest strength and best balance (OR .097, 95% CI .025-.38) or poorest balance and best strength (OR .102, 95% CI .012-.866) the risk was about 10%. The age-specific estimates of prevalence of severe walking disability in women were: 2.0% for ages 65-74 years, 3.4% for ages 75-84 years, and 9.1% for ages 85 years and older. The burden of coimpairments seems to be greater than the sum of single impairments involved. An effective way to reduce severe disabilities could be prevention of coimpairments.

Disability, physical activity, and muscle strength in older women: The women's health and aging study

Objective: To study associations of motor disability, physical activity, and muscle strength in older women, in particular to investigate whether model of spiraling decrease is expressed in the data. Design: Cross-sectional analysis using data from the base-line measurements of The Women's Health and Aging Study (WHAS). Setting: Participants' homes. Participants: A total of 1,002 disabled women aged 65 years and older living in the community. Outcome Measures: Motor disability was measured by the number of self-reported difficulties in grasping, lifting 101b, walking across a small room, walking 1 4 mile, climbing 10 steps, and doing heavy housework. Level of physical activity was determined from response to a series of questions on the frequency and amount of common activities and physical exercise. Hand grip and knee extension forces were measured using portable hand-held dynamometers. Results: Disability and physical activity were inversely associated, with inactivity being most common among the most disabled women. Those with poorer strength reported more difficulties in motor activities. Greater strength was found among the physically more active. In stratified analyses, the positive association of physical activity on knee extension strength was consistent across disability levels. Multiple regression analysis showed that both physical activity and muscle strength were significant predictors for severity of disability. Structural equation model (LISREL) showed that muscle strength had a mediating role between physical activity and disability; disability was associated with physical inactivity, which correlated with lower muscle strength, which was associated with greater degree of disability. Conclusion: Even though causality cannot be confirmed in this cross-sectional analysis, our findings suggested a spiraling model of decline in which muscle strength has a significant role.

Methodology and feasibility of a home-based examination in disabled older women: the Women's Health and Aging Study.

To ascertain disease and functional capacity in community-resident disabled older women in the Women's Health and Aging Study (WHAS), a prospective investigation of the causes and course of disability, a home-based standardized physical examination and performance test battery were developed. Thirty-nine tests were administered, 9 by a lay interviewer and 30 by a nurse. This scope and intensity of testing had not been performed previously in a home environment or on such a functionally limited population. Thus, substantial developmental work was required. This report describes the administrative procedures and field experience for each exam component, highlighting innovations pertinent to home administration. Exclusion criteria, safety issues, administration time, completion rates, and reasons for incomplete data are reported. Administration time is based on 30 exams conducted over a 3-week period 90% of the way through baseline data collection. Completion status was determined using all 1,002 participants and is categorized as follows: complete; partial; not done, health; not done, other; and refused. Seventy-two percent of the screened, eligible respondents completed the 30-min interviewer-administered physical assessment and the 2-hr, 10-min nurse examination. Classifiable data were obtained for 90% of participants on 36 examination items. Lower completion rates were obtained on the other three tests primarily due to exclusions for health-related conditions; environmental constraints and participant refusal were minimal. Extensive, research-oriented physical evaluation can be successfully and safely performed in a home setting. In future studies, home-based examination may be preferable, as participation in the WHAS examination substantially exceeded rates for clinic-based exams in similar populations.