Comorbidity and its impact on disability

Improving function in age-related macular degeneration: design and methods of a randomized clinical trial

Age-Related Macular Degeneration (AMD) is the leading cause of severe vision loss in older adults and impairs the ability to read, drive, and live independently and increases the risk for depression, falls, and earlier mortality. Although new medical treatments have improved AMD's prognosis, vision-related disability remains a major public health problem. Improving Function in AMD (IF-AMD) is a two-group randomized, parallel design, controlled clinical trial that compares the efficacy of Problem-Solving Therapy (PST) with Supportive Therapy (ST) (an attention control treatment) to improve vision function in 240 patients with AMD. PST and ST therapists deliver 6 one-hour respective treatment sessions to subjects in their homes over 2 months. Outcomes are assessed masked to treatment assignment at 3 months (main trial endpoint) and 6 months (maintenance effects). The primary outcome is targeted vision function (TVF), which refers to specific vision-dependent functional goals that subjects highly value but find difficult to achieve. TVF is an innovative outcome measure in that it is targeted and tailored to individual subjects yet is measured in a standardized way. This paper describes the research methods, theoretical and clinical aspects of the study treatments, and the measures used to evaluate functional and psychiatric outcomes in this population.

In-hospital death and adverse clinical events in elderly patients according to disease clustering: the REPOSI study

OBJECTIVE

The aim of the study was to recognize clusters of diseases among hospitalized elderly and to identify groups of patients at risk of in-hospital death and adverse clinical events according to disease clustering.

METHOD

This was a cross-sectional study conducted in 38 internal medicine and geriatric wards in Italy participating in the Registro Politerapie SIMI (REPOSI) study during 2008. The subjects were 1,332 inpatients aged 65 years or older. Clusters of diseases (i.e., two or more co-occurrent diseases) were identified using the odds ratios (OR) for the associations between pairs of conditions, followed by cluster analysis. Logistic regression models were used to evaluate the effect of disease clusters on in-hospital death and adverse clinical events.

RESULTS

A total of 86.7% of the patients were discharged, 8.3% were transferred to another hospital unit, and 5.0% died during hospitalization; 36.4% of the patients had at least one adverse clinical event. Patients affected by the clusters, including heart failure (HF) and either chronic renal failure (CRF) or chronic obstructive pulmonary disease, had a significant association with in-hospital death (OR, 4.3;95% confidence interval [CI], 1.6-11.5; OR, 2.9; 95% CI, 1.1-8.3, respectively), as well as patients affected by CRF and anemia (OR, 6.1; 95% CI, 2.3-16.2). The cluster including HF and CRF was also associated with adverse clinical events (OR, 3.5; 95% CI, 1.5-7.8). The effect of both HF and CRF and anemia and CRF on in-hospital death was additive.

CONCLUSION

Several groups of older patients at risk of in-hospital death and adverse clinical events were identified according to disease clustering. Knowledge of the relationship among co-occurring diseases may help developing strategies to improve clinical practice and preventative interventions.

Comorbidity among older American Indians: the native elder care study

Comorbidity is a growing challenge and the older adult population is most at risk of developing comorbid conditions. Comorbidity is associated with increased risk of mortality, increased hospitalizations, increased doctor visits, increased prescription medications, nursing home placement, poorer mental health, and physical disability. American Indians experience some of the highest rates of chronic conditions, but to date there have been only two published studies on the subject of comorbidity in this population. With a community-based sample of 505 American Indians aged 55 years or older, this study identified the most prevalent chronic conditions, described comorbidity, and identified socio-demographic, functional limitations, and psychosocial correlates of comorbidity. Results indicated that older American Indians experience higher rates of hypertension, diabetes, back pain, and vision loss compared to national statistics of older adults. Two-thirds of the sample experienced some degree of comorbidity according to the scale used. Older age, poorer physical functioning, more depressive symptomatology, and lower personal mastery were all correlates of higher comorbidity scores. Despite medical advances increasing life expectancy, morbidity and mortality statistics suggest that the health of older American Indians lags behind the majority population. These findings highlight the importance of supporting chronic care and management services for the older American Indian population.

The measurement of multiple chronic diseases--a systematic review on existing multimorbidity indices

BACKGROUND

Multimorbidity, defined as the coexistence of 2 or more chronic diseases, is a common phenomenon especially in older people. Numerous efforts to establish a standardized instrument to assess the level of multimorbidity have failed until now, and indices are primarily characterized by their high heterogeneity. Thus, the objective is to provide a comprehensive overview on existing instruments on the basis of a systematic literature review.

METHODS

The review was performed in MedLine. All articles published between January 1, 1960 and August 31, 2009 in German or English language, with the primary focus either on the development of a weighted index or on the effect of multimorbidity on different outcomes, were identified.

RESULTS

A total of 39 articles met the inclusion criteria. In the majority of studies (59.0%), the list of included diseases was presented without any selection criteria. Only the high prevalence of diseases (17.9%), their impact on mortality, function, and health status served as a point of reference. Information on the prevalence of chronic conditions mostly rely on self-reports. On average, the 39 indices included 18.5 diseases, ranging between 4 and 102 different conditions. Most frequently mentioned diseases were diabetes mellitus (in 97.5% of indices), followed by stroke (89.7%), hypertension, and cancer (each 84.6%). Overall, three different weighting methods could be distinguished.

CONCLUSIONS

The systematic literature further emphasis the heterogeneity of existing multimorbidity indices. However, one important similarity is that the focus is on diseases with a high prevalence and a severe impact on affected individuals.

Gender differences in physical disability among older adults in underprivileged communities in Lebanon

OBJECTIVE

To examine the role of health conditions, socioeconomic, and socioenvironmental factors in explaining gender differences in physical disability among older adults.

METHOD

We compared 412 women and 328 men residing in underprivileged communities in Lebanon on their activities of daily living (ADL), instrumental activities of daily living (IADL), and physical tasks (PT). Binary logistic regression analyses adjusting for possible explanatory covariates were conducted sequentially.

RESULTS

Women showed higher prevalence rates of ADL, IADL, and PT compared to men. Gender disparities in ADL disability were explained by chronic-disease risk factors and health conditions (OR = 1.46; 95% CI = 0.94-2.25). The odds of disability in IADL and PT remained significantly higher for women compared to men after accounting for all available covariates.

DISCUSSION

These results suggest underlying differences in functional status between women and men, yet, may have been influenced by the sensitivity of the measures to the social context and gendered environment surrounding daily activities.

Population attributable risk for functional disability associated with chronic conditions in Canadian older adults

OBJECTIVES

to investigate the population impact on functional disability of chronic conditions individually and in combination.

METHODS

data from 9,008 community-dwelling individuals aged 65 and older from the Canadian Study of Health and Aging (CSHA) were used to estimate the population attributable risk (PAR) for chronic conditions after adjusting for confounding variables. Functional disability was measured using activity of daily living (ADL) and instrumental activity of daily living (IADL).

RESULTS

five chronic conditions (foot problems, arthritis, cognitive impairment, heart problems and vision) made the largest contribution to ADL- and IADL-related functional disabilities. There was variation in magnitude and ranking of population attributable risk (PAR) by age, sex and definition of disability. All chronic conditions taken simultaneously accounted for about 66% of the ADL-related disability and almost 50% of the IADL-related disability.

CONCLUSIONS

in community-dwelling older adults, foot problems, arthritis, cognitive impairment, heart problems and vision were the major determinants of disability. Attempts to reduce disability burden in older Canadians should target these chronic conditions; however, preventive interventions will be most efficient if they recognize the differences in the drivers of PAR by sex, age group and type of functional disability being targeted.

Trajectory of functional status among older Taiwanese: Gender and age variations

Current findings on gender and age differences in health trajectories in later life are equivocal and largely based upon data derived from Western developed nations. This study examines gender and age variations in the trajectory of functional status among older adults in Taiwan, a non-Western newly industrialized society. Data came from a sample of some 3500 Taiwanese aged 60 and over, initially surveyed in 1989 and subsequently followed in 1993, 1996, 1999, and 2003. Hierarchical linear models with time-varying covariates were employed in depicting the dynamics of functional status across gender and age. Women and the old-old experienced higher levels of disability and rates of increase than their male and young-old counterparts. Moreover, older women bore a disproportionately larger burden of disability. There are therefore significant gender and age variations in the trajectory of functional status among older Taiwanese. These findings provide evidence for the generalizability of prior observations to a non-Western society.

Development of CRIteria to assess appropriate Medication use among Elderly complex patients (CRIME) project: rationale and methodology

Pharmacological treatment of complex older adults with comorbidities, multiple impairments in function, cognition, social status and geriatric syndromes represents a challenge for prescribing physicians and often results in a high rate of iatrogenic illnesses. Clinical guidelines are commonly used to indicate appropriate prescription, but they are often based on the results of clinical trials that are conducted on young subjects with a low level of complexity. Therefore, the recommendations of clinical guidelines may be difficult to apply to older complex adults. In this paper we present the rationale and methodology of the Development of CRIteria to assess appropriate Medication use among Elderly complex patients (CRIME) project, a study aimed at producing recommendations to evaluate the appropriateness of pharmacological prescription in older complex patients, translating the recommendations of clinical guidelines to this type of patient. A literature search will be performed to integrate and revise the recommendations of disease-specific guidelines on the pharmacological treatment of patients with common chronic conditions. New recommendations will be provided and approved in a consensus meeting of international experts. Both data from randomized controlled trials and observational studies will be used to meet this aim. Recommendations provided by the CRIME project are not meant to replace existing clinical guidelines, but they may be used to help physicians in the prescribing process. Once completed these recommendations should be validated in interventional studies.

[Comorbidity in the elderly: utility and validity of assessment tools]

Comorbidity is common in the elderly and contributes to the complexity of this population subgroup. This problem is a risk factor for major adverse events such as functional decline, disability, dependency, poor quality-of-life, institutionalization, hospitalization and death, but is not the most important factor. Age and risk of functional decline rather than comorbidity (understood as a compilation of diseases) are the main characteristics defining the target population attended by geriatricians. Comorbidity indexes should not be interpreted independently in the elderly, but within a context of comprehensive geriatric assessment that includes age-related preclinical dysfunctions, frailty measures, and functional, mental and psychosocial issues. The clinical management of comorbidity in the elderly requires advanced knowledge of geriatrics because the treatment of one condition may worsen or lead to the development of others and because preclinical physiological dysfunctions modulate drug response. Recommending a specific comorbidity index is difficult and depends on multiple factors, due to their psychometric characteristics, applicability in the elderly and their construct. However, the Cumulative Illness Rating Scale, in the version adapted to the elderly, could be highly suitable. Other instruments, such as the Charlson index, the Index of CoExistent Disease and the Kaplan index are also valid and reproducible.

Are features of the neighborhood environment associated with disability in older adults?

PURPOSE

To explore the association of features of a person's neighborhood environment with disability in daily activities.

METHOD

We recruited 436 people aged 65 years and over (mean 70.4 years (SD = 3.9)) with functional limitations from the Multicenter Osteoarthritis Study (MOST). Features of the neighborhood environment were assessed using the Home and Community Environment (HACE) survey. The Late-Life Disability Instrument (LLDI) was used to assess disability in daily activities. We used logistic regression to examine the association of individual environmental features with disability. RESULTS. Older adults whose neighborhoods did not have parks and walking areas less frequently engaged in a regular fitness program (OR = 0.4, 95% CI (0.2, 0.7)), and in social activities (OR = 0.5, 95% CI (0.3, 1.0)). Those whose neighborhoods had adequate handicap parking had 1.5-1.8 higher odds of engagement in several social and work role activities. The presence of public transportation was associated with 1.5-2.9 higher odds of not feeling limited in social, leisure, and work role activities, and instrumental activities of daily living.

CONCLUSION

Our exploratory study suggests that parks and walking areas, adequate handicap parking, and public transportation are associated with disability in older adults.

Maintaining independence in older people

Appropriate social and medical interventions may help maintain independence in older people. Determinants of functional decline, disability and reduced independence are recognized and specific interventions target the treatment of clinical conditions, multiple health problems and geriatric conditions, prevention of falls and fractures, and maintenance of physical and cognitive function and social engagement.

Preventive strategies to identify and treat diverse unmet needs of older people have been researched extensively. We reviewed systematically recent randomized controlled trials evaluating these ‘complex’ interventions and incorporated the findings of 21 studies into an established meta-analysis that included 108,838 people in 110 trials. There was an overall benefit of complex interventions in helping older people to live at home, explained by reduced nursing home admissions rather than death rates. Hospital admissions and falls were also reduced in intervention groups. Benefits were largely restricted to earlier studies, perhaps reflecting general improvements in health and social care for older people. The wealth of high-quality trial evidence endorses the value of preventive strategies to help maintain independence in older people.

Prevalence and correlates of functional status in an older community--representative sample in Brazil

OBJECTIVE

Information on dependency level of elderly in rapidly aging developing countries is limited, but this is needed to ascertain the extent of need for help with activities of daily living (ADLs).

METHOD

In-person information was obtained in 1995 from a statewide survey of representative community residents >/=60 years of age in the state of Rio Grande do Sul, Brazil (N = 7,040), on demographic characteristics, health conditions, social ties, health behaviors, and ADL performance.

RESULTS

Nearly 40% needed help with one or more ADLs. In controlled analyses, need for help approximately doubled with each succeeding decade. Increased education and income and regular physical activity reduced risk. Selected health conditions (stroke, depression, poor self-rated health) were consistently associated with need for help.

DISCUSSION

A large proportion of noninstitutionalized elderly have ADL problems. In addition to health care, interventions promoting equity of access to education and economic opportunity could reduce ADL dependency in coming generations.

Underuse of indicated medications among physically frail older US veterans at the time of hospital discharge: results of a cross-sectional analysis of data from the Geriatric Evaluation and Management Drug Study

BACKGROUND

Medication underutilization, or the omission of a potentially beneficial medication indicated for disease management, is common among older adults but poorly understood.

OBJECTIVES

The aims of this work were to assess the prevalence of medication underuse and to determine whether polypharmacy or comorbidity was associated with medication underuse among physically frail older veterans transitioning from the hospital to the community.

METHODS

This was a cross-sectional analysis of patients who were discharged from 11 US veterans' hospitals to outpatient care, based on data from the Geriatric Evaluation and Management Drug Study, a substudy of the Veterans Affairs Cooperative Study of geriatric evaluation and management. Patients were enrolled between August 31, 1995, and January 31, 1999. To qualify for the study, patients had to be aged > or =65 years, hospitalized in a medical or surgical ward for >48 hours, and meet > or =2 of the following criteria: moderate functional disability; recent cerebrovascular accident with residual neurological deficit; history of > or =1 fall in the previous 3 months; documented difficulty with walking (ie, requiring personal assistance or equipment), not including preadmission use of a wheelchair with ability to transfer to and from chair independently; malnutrition (admission serum albumin of 3.5 g/dL, <80% of ideal body weight, or recent > or =15-lb weight loss reported in admission history); dementia; depression; documented diagnosis of new fracture or revision needed of older fracture; unplanned admission within 3 months of previous admission; and prolonged bed rest. Clinical pharmacist/physician pairs reviewed medical records and medication lists and independently applied the Assessment of Underutilization (AOU) index to determine omissions of indicated medications. Discordances in index ratings were resolved during clinical consensus conferences. The primary outcome measure was the percentage of patients with > or =1 medication omission detected by the AOU. Multivariable logistic regression analyses identified factors associated with underuse.

RESULTS

A total of 384 patients were included in the study. The majority (53.6%) were between the ages of 65 and 74 years, and the mean (SD) Charlson comorbidity index was 2.44 (1.93). Overall, 374 patients (97.4%) were men and 274 (71.4%) were white. Medication undertreatment occurred in 238 participants (62.0%). Diseases of the Accepted for publication October 26, 2009. circulatory, endocrine/nutritional, musculoskeletal, and respiratory systems were the most commonly undertreated conditions. The indicated medications most likely to be omitted were nitrates for those with a history of myocardial infarction, multivitamins in those with malnutrition, and inhaled anticholinergics for chronic obstructive airways disease. Statistically significant factors associated with medication underuse included limitations in activities of daily living (adjusted odds ratio [AOR], 2.17 [95% CI, 1.27-3.71]; P = 0.01), being white (AOR, 1.70 [95% CI, 1.06-2.71]; P = 0.03), and Charlson comorbidity index (AOR, 1.13 for each 1-point increase [95% CI, 1.00-1.27]; P = 0.04). Discharge from a general medicine service as opposed to a surgical service was associated with lower risk of medication underuse (AOR, 0.61 [95% CI, 0.38-0.98]; P = 0.04).

CONCLUSIONS

Medication underuse was relatively common in this study. Patients with greater comorbidity, but not polypharmacy, had increased odds of undertreatment.

Understanding factors that influence success of home- and community-based services in keeping older adults in community settings

OBJECTIVE

To understand factors that influence success of home- and community-based services in keeping older adults in community settings, we examined the causal relationships among older adults' personal factors, older adults' home- and community-based services use, and older adults' remaining in communities.

METHODS

Structural equation modeling was employed to test a home- and community-based services model based on Andersen's Health Behavioral Model. Data from 5,294 elders in a nationally representative dataset, the Second Longitudinal Study of Aging, were included for analysis.

RESULTS

Two significant supportive factors for older adults to remain in communities were use of paid instrumental activities of daily living (IADL) personal care services and awareness of unmet needs.

DISCUSSION

Our findings suggest the importance of encouraging older adults to acknowledge their unmet needs and to seek community-based support services early, rather than wait until they have developed more serious needs, such as difficulties in activities of daily living (ADL).

Predictors of daily mobility skills 6 months post-discharge from acute care or rehabilitation in older adults with stroke living at home

PURPOSE

To determine the evolution of daily mobility skills from the timed up-and-go (TUG) upto 6 months after home return in older adults with stroke discharged from acute care or rehabilitation; and to identify the best predictive factors of the TUG at 6 months post-discharge.

METHODS

In this longitudinal prospective study, people with stroke aged 65 years or more and discharged home from an acute care hospital (n = 82) or a rehabilitation service (n = 109) were included. The TUG was measured at discharge (T1), and at 3 and 6 months post-discharge (T2 and T3). Correlations between the TUG at T3 and sociodemographic and clinical variables, as well as physical, cognitive, perceptual and psychological measures at T1, were used in a multiple regression model to identify the best predictors of TUG at T3.

RESULTS

TUG did not change between T1, T2 and T3 in the two groups of participants. The best predictors of TUG at T3 in participants from acute care were the use of a walking aid in daily life, age, deficits in oral expression and the presence of depressive symptoms. In participants from rehabilitation, predictors were the stage of motor recovery of the foot, the use of a walking aid in daily life, number of schooling years and memory impairments.

CONCLUSION

Daily mobility skills, as assessed with the TUG, did not deteriorate upto 6 months after home return in older adults with stroke. The best predictor of the TUG at T3 is the use of a walking aid during daily life in participants from acute care, and motor recovery of the foot in participants from rehabilitation.

Perceived need for mental health care among community-dwelling older adults

Only half of older adults with a mental disorder use mental health services, and little is known about the causes of perceived need for mental health care (MHC). We used logistic regression to examine relationships among depression, anxiety, chronic physical illness, alcohol abuse and/or dependence, sociodemographics, and perceived need among a national sample of community-dwelling individuals 65 years of age and older (the Collaborative Psychiatric Epidemiology Surveys data set). Less than half of respondents with depression or anxiety perceived a need for care. Perceived need was greater for respondents with more symptoms of depression regardless of whether they met diagnostic criteria for a mental illness. History of chronic physical conditions, history of depression or anxiety, and more severe mental illness were associated with greater perceived need for MHC. Future studies of perceived need should account for individual perceptions of mental illness and treatment and the influence of social networks.

Correlation between symptoms and function in older adults with comorbidity

OBJECTIVES

To describe the relationship between symptom scores and mobility function measures, assess whether symptom scores and disease scores are similarly associated with mobility function, and identify clusters of symptoms that are most strongly associated with functional status in older adults.

DESIGN

Secondary analysis of cross-sectional data from three cohorts.

SETTING

Academic medical center.

PARTICIPANTS

One hundred ninety-five community-dwelling subjects with poor flexibility or cardiorespiratory fitness (fitness cohort), 211 female retirement community residents with vertebral fractures (VF cohort), and 61 subjects with Parkinson's disease (PD cohort).

MEASUREMENTS

Twenty-item self-reported symptom scale, 17-item self-reported disease scale, Medical Outcomes Study 36-item Short Form Survey (SF-36) Physical Functioning Scale, 5-item Nagi Disability scale, 10-m walk time, supine to stand time.

RESULTS

Symptom scores correlated with mobility function measures (Spearman correlation coefficients ranged from 0.222 to 0.509) at least as strongly as, if not more strongly than, did disease scores. Symptom scores remained associated with functional outcomes after controlling for disease score and demographic variables. Adding symptom scores to models that contained disease scores significantly increased the association with functional outcomes. In the fitness cohort, muscle weakness was the most explanatory single symptom, associated with an average decrease of 17.8 points on the Physical Functioning Scale. A model that included only muscle weakness, pain, and shortness of breath accounted for 21.2% of the variability in the Physical Functioning Score.

CONCLUSION

Symptoms represent useful indicators of disability burden in older adults and are promising targets for interventions to improve function in medically complex patients.

Patterns of chronic multimorbidity in the elderly population

OBJECTIVES

To describe patterns of comorbidity and multimorbidity in elderly people.

DESIGN

A community-based survey.

SETTING

Data were gathered from the Kungsholmen Project, a urban, community-based prospective cohort in Sweden.

PARTICIPANTS

Adults aged 77 and older living in the community and in institutions of the geographically defined Kungsholmen area of Stockholm (N=1,099).

MEASUREMENTS

Diagnoses based on physicians' examinations and supported by hospital records, drug use, and blood samples. Patterns of comorbidity and multimorbidity were evaluated using four analytical approaches: prevalence figures, conditional count, logistic regression models, and cluster analysis.

RESULTS

Visual impairments and heart failure were the diseases with the highest comorbidity (mean 2.9 and 2.6 co-occurring conditions, respectively), whereas dementia had the lowest (mean 1.4 comorbidities). Heart failure occurred rarely without any comorbidity (0.4%). The observed prevalence of comorbid pairs of conditions exceeded the expected prevalence for several circulatory diseases and for dementia and depression. Logistic regression analyses detected similar comorbid pairs. The cluster analysis revealed five clusters. Two clusters included vascular conditions (circulatory and cardiopulmonary clusters), and another included mental diseases along with musculoskeletal disorders. The last two clusters included only one major disease each (diabetes mellitus and malignancy) together with their most common consequences (visual impairment and anemia, respectively).

CONCLUSION

In persons with multimorbidity, there exists co-occurrence of diseases beyond chance, which clinicians need to take into account in their daily practice. Some pathological mechanisms behind the identified clusters are well known; others need further clarification to identify possible preventative strategies.

Effect of early conditions on disability among the elderly in Latin America and the Caribbean

Poor early conditions have been associated with increasing risks of some chronic diseases during adulthood. Since chronic illnesses are known to be important risk factors for disability, poor early conditions should predict disability at older ages. In addition, recent literature suggests that poor early conditions may affect the risk of disability even in the absence of chronic illnesses. We aimed to evaluate the magnitude of differentials in the risk of being disabled according to early conditions experienced by elderly populations in Latin America and the Caribbean, and to identify the group of chronic illnesses responsible for it. We find that poor early conditions exert a strong influence on disability later in life in two ways: by increasing the risk of suffering disability-related chronic illnesses and by increasing the risks of suffering disabilities by those with chronic illnesses.

The impact of chronic multimorbidity and disability on functional decline and survival in elderly persons. A community-based, longitudinal study

OBJECTIVE

We aimed to disentangle the effect of chronic multimorbidity and disability on 3-year functional decline and survival in the elderly.

DESIGN

Prospective cohort study with a mean of follow-up of 2.8 years.

SETTING

Swedish elderly persons from the Kungsholmen Project (1987-2000).

SUBJECTS

A total of 1099 subjects, 77-100 years old, living in the community and institutions.

MAIN OUTCOME MEASUREMENTS

Medical diagnoses (based on clinical examination, drug use, medical records and blood tests), and functional assessment (according to Katz Index) at baseline were investigated in relation to functional decline and death occurring during follow-up.

RESULTS

At baseline, 12.1% of participants had disability, and 52.3% were affected by multimorbidity. During follow-up, 363 persons died and 85 worsened in functioning. The number of chronic conditions incrementally increased the risk of functional decline [hazard ratio (HR) increased from 1.5 in subjects with one disease to 6.2 in persons with 4+ diseases]. However, this was not the case for mortality, as the HR of death was the same for people with one disease as well as 4+ diseases (HR=2.3). Baseline disability had the highest impact on survival, independently of number of diseases [HR=8.1; 95% confidence interval (CI)=4.8-13.7 in subjects with one disease and HR=7.7; 95% CI=4.7-12.6 in those with 2+ diseases].

CONCLUSIONS

In the elderly subjects, chronic disability rather than multimorbidity emerged as the strongest negative prognostic factor for functionality and survival.

Disability and its correlates with chronic morbidities among U.S. adults aged 50-<65 years

OBJECTIVE

To examine the prevalence of disability and its associations with multiple chronic morbidities in U.S. adults aged 50-<65 years.

METHODS

Self-reported data on disability and chronic morbidities were collected from 95,103 participants (aged 50-<65 years) of the 2005 Behavioral Risk Factor Surveillance System. Prevalence estimates for disability and chronic morbidities were age-standardized to the 2000 U.S. population. Adjusted odds ratios for disability among people with chronic morbidities (versus those without) were estimated using logistic regression analyses.

RESULTS

The age-adjusted prevalence of the six chronic morbidities ranged from 3.1% (for stroke) to 40.3% (for arthritis). Overall, the prevalence of disability was 26.3%; it was significantly higher in adults with chronic morbidities than in those without and increased linearly with the number of the chronic morbidities. Adults with any of the chronic morbidities were 1.9 to 4.5 times as likely, and adults with 1 to 5-6 of the chronic morbidities were 2.7 to 42.9 times as likely, to have disability as those without after adjustment for demographics, smoking and leisure-time exercise.

CONCLUSIONS

Chronic morbidities remain major factors associated with disability in adults aged 50-<65 years. Effective interventions to prevent and manage chronic diseases from an earlier age may help reduce the risk of disability.

[Health profile of the elderly in Brazil: analysis of the 2003 National Household Sample Survey using the Grade of Membership method]

The aim of this study was to identify functional disability and health profiles of the elderly in Brazil, as well as their prevalence rates, based on the National Household Sample Survey for 2003. The sample size was 33,786 elderly individuals. Grade of Membership was used to define the profiles: "healthy elderly" (Profile 1), whose pure types had a lower probability of disability and chronic illness; "elderly with mild functional disability" (Profile 2), whose pure types had mainly hypertension and lower back problems and were independent in activities of daily living, although with high difficulty in mobility; and "elderly with severe disability" (Profile 3), with higher probability of chronic illness, high difficulty with activities of daily living, and high dependency in terms of mobility. In conclusion, the profiles indicate that a consistent approach to functional disability is essential for promoting the health of the elderly.

Arthritis disability and heart disease disability

OBJECTIVE

Arthritis is the most common health condition in midlife and late life, and heart disease is the leading cause of death. This article compares disability impacts of these 2 preeminent health problems.

METHODS

Using data from the National Health Interview Survey Disability Supplement, we studied specific limitations and disabilities, accommodations used (buffers), and accommodations needed (barriers) for US population groups of adults with arthritis disability, heart disease disability, both arthritis and heart disease disability, and disability due to other conditions. Weights and complex SE adjusted for sample design. We hypothesized that arthritis disability is more extensive and troublesome than heart disease disability.

RESULTS

People with arthritis disability had more numerous, longer, and more bothersome disabilities than people with heart disease disability. People with arthritis disability used more equipment and rehabilitation, whereas people with heart disease disability emphasized personal assistance, medications, and medical services. People with arthritis disability experienced more barriers and needs in activities and services. People with disabilities from both arthritis and heart disease were especially disadvantaged, with high levels of limitations and accommodations. People with disability from other conditions had the highest social participation, fewest disabilities, and most tailored accommodations of all groups.

CONCLUSION

Arthritis had higher and more extensive disability impact than heart disease. Both groups had more difficulty, buffers, and barriers in their lives than people disabled by other conditions. Therefore, arthritis and heart disease are premier conditions for disability attention and alleviation in the US population.

Comorbidity and mortality following hip fracture: a population-based cohort study

BACKGROUND AND AIMS

Identifying predictors for mortality following hip fracture is essential in order to improve survival, especially among the elderly. We compared mortality after hip fracture to controls without hip fracture, and assessed the impact of comorbidity on mortality following hip fracture in a population-based cohort study.

METHODS

The health care databases in Western Denmark (1.4 million inhabitants) were used to identify all persons > or = 40 years of age with first-time hospitalization for hip fracture between 1/1/1998 and 1/31/2003. Five population controls without hip fracture were matched to hip fracture patients on age and gender. Prior hospitalization for selected comorbidities among hip fracture subjects was assessed from hospital discharge registries. Cox regression analysis was used to compute crude and adjusted relative risks and 95% confidence intervals for 30-day, 90-day, and 1-year mortality associated with hip fracture, and with prior hospital history of selected comorbidities.

RESULTS

The cohort was followed for an average of 22 months. Females comprised 71% of the cohort and 90% was aged 65 years or older. Compared to persons without hip fracture, persons with hip fracture had from 2 to >3-fold higher risk of death at 1 year. History of congestive heart failure (CHF), chronic obstructive pulmonary disease (COPD), dementia, tumor, and malignancy increased adjusted 1-year mortality from 50% to 3-fold among persons with hip fracture.

CONCLUSIONS

Hip fracture increased 1-year mortality more than 3-fold compared with mortality without hip fracture. Among hip fracture subjects, the presence of selected comorbidities further increased the risk of mortality after hip fracture.

Gender differences in functional status in middle and older age: are there any age variations?

OBJECTIVES

The present study examines gender differences in changes in functional status after age 50 and how such differences vary across different age groups.

METHODS

Data came from the Health and Retirement Study, involving up to six repeated observations of a national sample of Americans older than 50 years of age between 1995 and 2006. We employed hierarchical linear models with time-varying covariates in depicting temporal variations in functional status between men and women.

RESULTS

As a quadratic function, the worsening of functional status was more accelerated in terms of the intercept and rate of change among women and those in older age groups. In addition, gender differences in the level of functional impairment were more substantial in older persons than in younger individuals, although differences in the rate of change between men and women remained constant across age groups.

DISCUSSION

A life course perspective can lead to new insights regarding gender variations in health within the context of intrapersonal and interpersonal differences. Smaller gender differences in the level of functional impairment in the younger groups may reflect improvement of women's socioeconomic status, greater rate of increase in chronic diseases among men, and less debilitating effects of diseases.

From Bedside to Bench: summary from the American Geriatrics Society/National Institute on Aging Research Conference on Comorbidity and Multiple Morbidity in Older Adults

Most aging patients have multiple concurrent health problems. However, most current medical practice and research are largely based on a single disease model, failing to account for the simultaneous presence of multiple conditions. Clinical trials, practice guidelines, and pay-for-performance schemes may thus have limited applicability in older patients. We report on the 2005 American Geriatrics Society/National Institute on Aging conference on Comorbid Disease and Multiple Morbidity in an Aging Society. The two-day conference was designed to clarify concepts of multiple concurrent health conditions; explore implications for causation, health, function and systems of care; identify important gaps in knowledge; and propose useful next steps. While the conference did not attempt to standardize terminology, we here develop the concepts of comorbidity, multiple morbidity, condition clusters, physiological health, and overall health as they were used. The present report also summarizes sessions addressing the societal burden of comorbidity, and clinical research on particular diseases within the framework of comorbidity concepts. Next steps recommended include continuing clarification of terms and conceptual approaches, consideration of developing and improving measures, as well as developing new research directions.

Health of community-dwelling adults with mobility limitations in the United States: prevalent health conditions. Part I

OBJECTIVE

To characterize the extent and types of prevalent health conditions among nationally representative groups of adults with mobility, nonmobility, and no limitations.

DESIGN

Data were collected during 5 rounds of household interviews from a probability subsample of households that represent the civilian, noninstitutionalized U.S. population. With some exceptions, round 1 variables were used for this analysis.

SETTING

Community.

PARTICIPANTS

Data were analyzed on the same respondents from the 1996 to 1997 Medical Expenditure Panel Survey (MEPS) and the 1995 National Health Interview Survey Disability Supplement. Respondents were categorized into 3 groups for analysis: those with mobility limitations, nonmobility limitations; and no limitations. The analytic sample included 13,897 MEPS adults (> or =18y).

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Number, types, and prevalence of self-reported health conditions compared across groups.

RESULTS

On average, adults with mobility limitations had significantly more prevalent conditions (3.6) than those with nonmobility limitations (2.4), or no limitations (1.3). Greater comorbidity existed in the context of fewer personal resources and more than half of adults with mobility limitations were working age.

CONCLUSIONS

Determining factors that influence the health of adults with mobility limitations is a critical public health issue.

Is stroke the most common cause of disability?

BACKGROUND

It is widely stated that stroke is the most common cause of severe disability. We aimed to examine whether this claim is supported by any evidence.

METHODS

We conducted secondary analysis of the Office of National Statistics 1996 Survey of Disability, United Kingdom. This was a multistage stratified random sample of 8683 noninstitutionalized individuals aged between 16 and 101 years, mean 62 years, response rate 83% (n = 8816). The outcome used was the Office of Population Censuses and Surveys severity scale for disability. Odds ratios and population-attributable fractions were calculated to examine the associations between diagnoses and disability.

RESULTS

Logistic regression modelling suggests that, after adjustment for comorbidity and age, those with stroke had the highest odds of reporting severe overall disability (odds ratio 4.88, 95% confidence interval [CI] 3.37-6.10). Stroke was also associated with more individual domains of disability than any of the other conditions considered. Adjusted population-attributable fractions were also calculated and indicated that musculoskeletal disorders had the highest population-attributable fraction (30.3%, 95% CI 26.2-34.1) followed by mental disorders (8.2%, 95% CI 6.9-9.5) and stroke (4.5%, 95% CI 3.6-5.3).

CONCLUSION

Stroke is not the most common cause of disability among the noninstitutionalized United Kingdom population. However, stroke is associated with the highest odds of reporting severe disability. Importantly, stroke is associated with more individual domains of disability compared with other conditions and might be considered to be the most common cause of complex disability.

Co-morbidity does not reflect complexity in internal medicine patients

Internal medicine patients are mostly elderly; they have multiple co-morbidities, which are usually chronic, rather than self-limiting or acute diseases. Neither administrative indicators nor co-morbidity indexes, though validated in elderly patients, are able to completely define these "complex" patients or to allow physicians to correctly "cope" with them. For the complex patients found in internal medicine wards, internists need not only to find the best diagnosis and treatment, but also to apply a complex intervention (i.e., a comprehensive assessment and both continuous and multi-disciplinary care) in order to maintain their health and ability to function and to prevent or delay disability, frailty, and displacement from home and community. The aim of this review is to underscore the differences between the concepts of co-morbidity and complexity, to discuss instruments for their measurement, and to highlight related implications, areas of uncertainty, and the responsibilities of internists in the assessment and management of inpatients of their wards. The conclusion we come to is that it is mandatory to shift from a finance/administrative-based management system to a clinical process model (clinical governance) driven by the quality of the medical outcome and the cost of achieving that outcome. From a "complexity theory" standpoint, patient-centered care and collaboration can be seen as simple rules that guide desirable behaviors in a complex system. By exploring the real complexity of our patients, we exercise the holistic, anthropologic medicine of the person that is internal medicine.

A influência das doenças crônicas na capacidade funcional dos idosos do Município de São Paulo, Brasil

O objetivo principal deste estudo foi investigar a influência de doenças crônicas (hipertensão arterial, diabetes mellitus, doença cardíaca, doença pulmonar, câncer e artropatia) na capacidade funcional (atividades de vida diária - AVDs - e atividades instrumentais de vida diária - AIVDs) dos idosos, controlando por idade, sexo, arranjo familiar, educação e presença de outras comorbidades. Os dados foram obtidos do Projeto SABE que inclui pessoas de 60 anos e mais, residentes no Município de São Paulo, Brasil, entre janeiro de 2000 e março de 2001. A amostra foi constituída de 1.769 idosos. Para a análise dos dados foi utilizada a regressão logística multinomial múltipla. Em comparação com a categoria de referência independente, as doenças que exercem uma significativa influência na categoria dependente nas AIVDs são a doença cardíaca (OR = 1,82), a artropatia (OR = 1,59), a doença pulmonar (OR = 1,50) e a hipertensão arterial (OR = 1,39). Quanto à resposta na categoria dependente nas AIVDs e AVDs, os resultados mostram que a doença pulmonar (OR = 2,58), a artropatia (OR = 2,27), a hipertensão arterial (OR = 2,13) e a doença cardíaca (OR = 2,10) demonstram um forte efeito. Os resultados são estatisticamente significativos (p < 0,05).

Framework for evaluating disease severity measures in older adults with comorbidity

BACKGROUND

Accounting for the influence of concurrent conditions on health and functional status for both research and clinical decision-making purposes is especially important in older adults. Although approaches to classifying severity of individual diseases and conditions have been developed, the utility of these classification systems has not been evaluated in the presence of multiple conditions.

METHODS

We present a framework for evaluating severity classification systems for common chronic diseases. The framework evaluates the: (a) goal or purpose of the classification system; (b) physiological and/or functional criteria for severity graduation; and (c) potential reliability and validity of the system balanced against burden and costs associated with classification.

RESULTS

Approaches to severity classification of individual diseases were not originally conceived for the study of comorbidity. Therefore, they vary greatly in terms of objectives, physiological systems covered, level of severity characterization, reliability and validity, and costs and burdens. Using different severity classification systems to account for differing levels of disease severity in a patient with multiple diseases, or, assessing global disease burden may be challenging.

CONCLUSIONS

Most approaches to severity classification are not adequate to address comorbidity. Nevertheless, thoughtful use of some existing approaches and refinement of others may advance the study of comorbidity and diagnostic and therapeutic approaches to patients with multimorbidity.

Continuity of care and general wellbeing of patients with comorbidities requiring joint replacement

AIM

The aim of this paper is to examine the continuity of care and general wellbeing of patients with comorbidities undergoing elective total hip or knee joint replacement.

BACKGROUND

Advances in medical science and improved lifestyles have reduced mortality rates in most Western countries. As a result, there is an ageing population with a concomitant growth in the number of people who are living with multiple chronic illnesses, commonly referred to as comorbidities. These patients often require acute care services, creating a blend of acute and chronic illness needs. For example, joint replacement surgery is frequently performed to improve impaired mobility associated with osteoarthritis.

METHOD

A purposive sample of twenty participants with multiple comorbidities who required joint replacement surgery was recruited to obtain survey, interview and medical record audit data. Data were collected during 2004 and 2005.

FINDINGS

Comorbidity care was poorly co-ordinated prior to having surgery, during the acute care stay and following surgery and primarily entailed prescribed medicines. The main focus in acute care was patient throughput following joint replacement surgery according to a prescribed clinical pathway. General wellbeing was less than optimal: participants reported pain, fatigue, insomnia and alterations in urinary elimination as the chief sources of discomfort during the course of the study.

CONCLUSION

Continuity of care of comorbidities was lacking. Comorbidities affected patient general wellbeing and delayed recovery from surgery. Acute care, clinical pathways and the specialisation of medicine and nursing subordinated the general problem of patients with comorbidities. Systems designed to integrate and co-ordinate chronic illness care had limited application in the acute care setting. A multidisciplinary, holistic approach is required. Recommendations for further research conclude this paper.

Comorbidity and disability in elderly Mexican and Mexican American adults: findings from Mexico and the southwestern United States

This article aims to compare the effects of morbid and comorbid medical conditions on disability in elderly Mexican and Mexican American adults. Data from the 2001 Mexican Health and Aging Study (N = 4,872) and 1993 to 1994 Hispanic Established Population for Epidemiologic Studies of the Elderly (N = 3,050) were analyzed. Prevalence of medical conditions and disability in activities of daily living were calculated and logistic models were used to test associations. Prevalence of disability in older Mexicans was 16.3% while it was slightly lower in Mexican Americans (13.1%). Prevalence of arthritis, cancer, diabetes, heart attack, and stroke were substantially higher in Mexican Americans than in older adults living in Mexico. Diabetes, stroke, and heart attack were comorbid conditions that raised the likelihood of disability in both populations among subjects with other medical conditions. Despite differences in prevalence, the associations of morbidity and comorbidity with disability had similar magnitudes in both populations.

Disability weights for comorbidity and their influence on health-adjusted life expectancy

Background

Comorbidity complicates estimations of health-adjusted life expectancy (HALE) using disease prevalences and disability weights from Burden of Disease studies. Usually, the exact amount of comorbidity is unknown and no disability weights are defined for comorbidity.

Methods

Using data of the Dutch national burden of disease study, the effects of different methods to adjust for comorbidity on HALE calculations are estimated. The default multiplicative adjustment method to define disability weights for comorbidity is compared to HALE estimates without adjustment for comorbidity and to HALE estimates in which the amount of disability in patients with multiple diseases is solely determined by the disease that leads to most disability (the maximum adjustment method). To estimate the amount of comorbidity, independence between diseases is assumed.

Results

Compared to the multiplicative adjustment method, the maximum adjustment method lowers HALE estimates by 1.2 years for males and 1.9 years for females. Compared to no adjustment, a multiplicative adjustment lowers HALE estimates by 1.0 years for males and 1.4 years for females.

Conclusion

The differences in HALE caused by the different adjustment methods demonstrate that adjusting for comorbidity in HALE calculations is an important topic that needs more attention. More empirical research is needed to develop a more general theory as to how comorbidity influences disability.

The association between morbidity and radiographic hand osteoarthritis: a population-based study

OBJECTIVES

Osteoarthritis is the most common form of joint disease and is considered to be a risk factor for other morbidities. We performed a population-based study to evaluate the association between morbidity and radiographic hand osteoarthritis.

METHODS

Our population consisted of Chuvashians residing in peripheral villages of the Russian Federation. The investigated cohort included 434 males aged 18-86 years and 385 females aged 18-84 years. Osteoarthritis development was evaluated using the Kellgren and Lawrence grading scheme. Morbidity data was attained from their medical records and divided into 14 categories by an experienced research physician. To explore the relationship between morbidity and age-adjusted radiographic hand osteoarthritis score, one-way analysis of variance was used, with hand osteoarthritis score as a dependent variable and individuals affected vs. non-affected with the specific disease as an independent (grouping) variable.

RESULTS AND CONCLUSIONS

Statistically significant evidence linking radiographic hand osteoarthritis and morbidities was found in patients with ischemic heart disease and gastrointestinal diseases. Our research indicates that individuals with ischemic heart disease have higher values of radiographic hand osteoarthritis, compared to lower values in individuals with gastrointestinal diseases. Additional research is needed to understand the biological mechanisms of the association between morbidity and osteoarthritis.

Development and validation of an index to predict activity of daily living dependence in community-dwelling elders

BACKGROUND

Maintaining independence in daily functioning is an important health outcome in older adults. A key measure of functional independence in elders is the ability to do activities of daily living (ADL) without the assistance of another person. However, few prognostic indices have been developed that stratify elders into groups at variable risk for developing ADL dependence.

OBJECTIVE

We sought to develop and validate a prognostic index that distinguishes between elders at different risk of ADL dependence.

RESEARCH DESIGN, SUBJECTS, AND MEASURES

We studied subjects enrolled in Asset and Health Dynamics Among the Oldest Old (AHEAD), a nationally representative cohort of elders older than the age of 70. We included 5239 subjects (mean age, 77) reporting that they could do each of 5 ADL (bathing, dressing, toileting, transferring, and eating) without the assistance of another person at baseline. Subjects were divided into development (n = 3245) and validation (n = 1994) samples based on region of the United States. Our primary outcome was the need for help (dependence) with at least one ADL at 2 years. We used logistic regression to select among predictor variables encompassing several domains: demographic characteristics, comorbid conditions, functional status, cognitive status, and general health indicators.

RESULTS

The 9 independent predictors of 2-year ADL dependence were age older than 80, diabetes, difficulty walking several blocks, difficulty bathing or dressing, need for help with personal finances, difficulty lifting 10 pounds, inability to name the Vice President, history of falling, and low body mass index. We created a risk score by assigning 1 point to each risk factor. In the development sample, rates of 2-year ADL dependence in subjects with 0, 1, 2, 3, 4, and 5 or more risk factors were 1.3%, 2.8%, 3.8%, 10%, 22%, and 33%, respectively (P < 0.001, roc area = 0.79). In the validation sample, the rates were 0.7%, 4.3%, 8.7%, 11%, 18%, and 40% (P < 0.001, roc area = 0.77). The risk score also discriminated between subjects at variable risk for a combined outcome of either ADL decline or death (4.3%, 7.6%, 15%, 21%, 30%, and 47%).

CONCLUSION

Using data available from patient reports, we validated a simple risk index that distinguished between elders at variable risk of ADL dependence. This index may be useful for identifying elders at high risk of poor outcomes or for risk adjustment.

Population-Based Medical and Disease Management: An Evaluation of Cost and Quality

Reports by the Institute of Medicine and the Health Care Financing Administration have emphasized that the integration of medical care delivery, evidence-based medicine, and chronic care disease management may play a significant role in improving the quality of care and reducing medical care costs. The specific aim of this project is to assess the impact of an integrated set of care coordination tools and chronic disease management interventions on utilization, cost, and quality of care for a population of beneficiaries who have complementary health coverage through a plan designed to apply proactive medical and disease management processes. The utilization of health care services by the study population was compared to another population from the same geographic service area and covered by a traditional fee-for-service indemnity insurance plan that provided few medical or disease management services. Evaluation of the difference in utilization was based on the difference in the cost per-member-per-month (PMPM) in a 1-year measurement period, after adjusting for differences in fee schedules, case-mix and healthcare benefit design. After adjustments for both case-mix and benefit differences, the study group is $63 PMPM less costly than the comparison population for all members. Cost differences are largest in the 55-64 and 65 and above age groups. The study group is $115 PMPM lower than the comparison population for the age category of 65 years and older, after adjustments for case-mix and benefits. Health Plan Employer and Data Information Set (HEDIS)-based quality outcomes are near the 90th percentile for most indications. The cost outcomes of a population served by proactive, population-based disease management and complex care management, compared to an unmanaged population, demonstrates the potential of coordinated medical and disease management programs. Further studies utilizing appropriate methodologies would be beneficial.

Subjective assessments of comorbidity correlate with quality of life health outcomes: initial validation of a comorbidity assessment instrument

Background

Interventions to improve care for persons with chronic medical conditions often use quality of life (QOL) outcomes. These outcomes may be affected by coexisting (comorbid) chronic conditions as well as the index condition of interest. A subjective measure of comorbidity that incorporates an assessment of disease severity may be particularly useful for assessing comorbidity for these investigations.

Methods

A survey including a list of 25 common chronic conditions was administered to a population of HMO members age 65 or older. Disease burden (comorbidity) was defined as the number of self-identified comorbid conditions weighted by the degree (from 1 to 5) to which each interfered with their daily activities. We calculated sensitivities and specificities relative to chart review for each condition. We correlated self-reported disease burden, relative to two other well-known comorbidity measures (the Charlson Comorbidity Index and the RxRisk score) and chart review, with our primary and secondary QOL outcomes of interest: general health status, physical functioning, depression screen and self-efficacy.

Results

156 respondents reported an average of 5.9 chronic conditions. Median sensitivity and specificity relative to chart review were 75% and 92% respectively. QOL outcomes correlated most strongly with disease burden, followed by number of conditions by chart review, the Charlson Comorbidity Index and the RxRisk score.

Conclusion

Self-report appears to provide a reasonable estimate of comorbidity. For certain QOL assessments, self-reported disease burden may provide a more accurate estimate of comorbidity than existing measures that use different methodologies, and that were originally validated against other outcomes. Investigators adjusting for comorbidity in studies using QOL outcomes may wish to consider using subjective comorbidity measures that incorporate disease severity.

The Effect of Diabetes on Disability in Middle-Aged and Older Adults

BACKGROUND

Physical disability is increasingly recognized as an adverse health consequence of type 2 diabetes in older adults. We studied the effect of diabetes on disability in middle-aged and older adults to: 1) characterize the association of diabetes with physical disability in middle-aged adults, and 2) determine the extent to which the effect of diabetes is explained by related covariates in either or both age groups.

METHODS

We used data from two parallel national panel studies of middle-aged and older adults to study the effect of self-reported diabetes at baseline on disability 2 years later, adjusting for baseline covariates.

RESULTS

Diabetes was strongly associated with subsequent physical disability (measured by a composite variable combining activities of daily living, mobility, and strength tasks) in middle-aged and older adults. Controlling for socioeconomic characteristics and common diabetes-related and unrelated comorbidities and conditions reduced the diabetes effect substantially, but it remained a significant predictor of disability in both groups.

CONCLUSIONS

Our analyses demonstrated that disability is an important diabetes-related health outcome in middle-aged and older adults that should be prevented or mitigated through appropriate diabetes management.