Income and the midlife peak in common mental disorder prevalence.

BACKGROUND: The prevalence of psychological distress and common mental disorders has been shown to peak in midlife but analyses have ignored the association of poor material circumstances with prevalence. This study aimed to test the hypothesis that the midlife prevalence peak occurs only in lower-income households. METHOD: Pooled data were used from the annual Health Survey for England, a nationally representative cross-sectional study, on community-dwelling individuals aged ≥ 16 years from years 1997 to 2006 (n=100 457). 12-item General Health Questionnaire scores, reported mental illness diagnoses and receipt of relevant medication were assessed in relation to household income and age. Analyses were separated by gender and adjusted for age, ethnicity, smoking, social class, education and co-morbidities. RESULTS: Prevalence of psychological distress, diagnoses and treatments rose with age until early middle age and declined subsequently. In analyses conducted separately by income categories, this pattern was marked in low-income groups but absent in high-income groups. Income-related inequalities in the prevalence of psychological distress were greatest in midlife; for example, in men aged 45-54 years the odds ratio of receiving psychiatric medication in the lowest income group compared with the highest was 7.50 [95% confidence interval (CI) 4.24-13.27] and in women aged 45-54 years the odds ratio of reporting mental illness was 10.25 (95% CI 6.16-17.05). CONCLUSIONS: An increased prevalence of psychological distress, common mental disorder diagnoses and treatment in midlife is not a universal phenomenon but is found only in those in low-income households. This implies the phenomenon is not inevitable but is potentially manageable or preventable.

Serum albumin concentration and cognitive impairment.

Results from clinical samples suggest low serum albumin may be associated with cognitive impairment, though evidence from population-based studies is inconclusive. Participants were 1,752 adults (699 men and 1,053 women) aged 65 years and over from the Health Survey for England 2000, a nationally representative population-based study. Cognitive impairment was assessed using the Abbreviated Mental Test Score. The cross-sectional relation of serum albumin quartiles to cognitive impairment was modelled using logistic regression. Two hundred and twelve participants were cognitively impaired (68 men and 144 women). Odds ratios (95% confidence intervals) for cognitive impairment in the first (2.2-3.8 g/dl), second (3.9-4.0 g/dl), and third (4.1-4.3 g/dl) quartiles of serum albumin compared with the fourth (4.4-5.3 g/dl) were 2.5 (1.3-5.1), 1.7 (0.9-3.5), and 1.5 (0.7-2.9), after adjustment for age, sex, education and additional risk factors for cognitive impairment (p for linear trend = 0.002). A highly similar pattern of associations was observed for men and women. Our data provide new evidence to suggest that low serum albumin is independently associated with increased odds of cognitive impairment in the elderly population.

Surrogate consent for dementia research: a national survey of older Americans.

BACKGROUND: Research in novel therapies for Alzheimer disease (AD) relies on persons with AD as research subjects. Because AD impairs decisional capacity, informed consent often must come from surrogates, usually close family members. But policies for surrogate consent for research remain unsettled after decades of debate. METHODS: We designed a survey module for a random subsample (n = 1,515) of the 2006 wave of the Health and Retirement Study, a biennial survey of a nationally representative sample of Americans aged 51 and older. The participants answered questions regarding one of four randomly assigned surrogate-based research (SBR) scenarios: lumbar puncture study, drug randomized control study, vaccine study, and gene transfer study. Each participant answered three questions: whether our society should allow family surrogate consent, whether one would want to participate in the research, and whether one would allow one's surrogate some or complete leeway to override stated personal preferences. RESULTS: Most respondents stated that our society should allow family surrogate consent for SBR (67.5% to 82.5%, depending on the scenario) and would themselves want to participate in SBR (57.4% to 79.7%). Most would also grant some or complete leeway to their surrogates (54.8% to 66.8%), but this was true mainly of those willing to participate. There was a trend toward lower willingness to participate in SBR among those from ethnic or racial minority groups. CONCLUSIONS: Family surrogate consent-based dementia research is broadly supported by older Americans. Willingness to allow leeway to future surrogates needs to be studied further for its ethical significance for surrogate-based research policy.

Use of statins and incidence of dementia and cognitive impairment without dementia in a cohort study.

OBJECTIVE: Evidence of a relation between use of lipid lowering drugs and cognitive outcomes is mixed. This study aimed to test the association between use of statins and incidence of dementia and cognitive impairment without dementia (CIND) over 5 years of follow-up. METHODS: Data were from a population-based cohort study comprising 1,789 older Mexican Americans. All participants had cognitive and clinical evaluations performed every 12 to 15 months. Participants who fell below specified cutpoints on cognitive tests were then evaluated clinically. Dementia diagnoses were finalized by an adjudication team. A total of 1,674 participants free of dementia/CIND at baseline were included in these analyses. Statin use was verified at each participant's home by medicine cabinet inspection. Cox proportional hazards models were used to evaluate the association between statin use and incidence of dementia/CIND. RESULTS: Overall, 452 of 1,674 participants (27%) took statins at any time during the study. Over the 5-year follow-up period, 130 participants developed dementia/CIND. In Cox proportional hazards models adjusted for education, smoking status, presence of at least one APOE epsilon4 allele, and history of stroke or diabetes at baseline, persons who had used statins were about half as likely as those who did not use statins to develop dementia/CIND (HR = 0.52; 95% CI 0.34, 0.80). CONCLUSION: Statin users were less likely to have incident dementia/cognitive impairment without dementia during a 5-year follow-up. These results add to the emerging evidence suggesting a protective effect of statin use on cognitive outcomes.

Prevalence of dementia in the United States: the aging, demographics, and memory study.

AIM: To estimate the prevalence of Alzheimer's disease (AD) and other dementias in the USA using a nationally representative sample. METHODS: The Aging, Demographics, and Memory Study sample was composed of 856 individuals aged 71 years and older from the nationally representative Health and Retirement Study (HRS) who were evaluated for dementia using a comprehensive in-home assessment. An expert consensus panel used this information to assign a diagnosis of normal cognition, cognitive impairment but not demented, or dementia (and dementia subtype). Using sampling weights derived from the HRS, we estimated the national prevalence of dementia, AD and vascular dementia by age and gender. RESULTS: The prevalence of dementia among individuals aged 71 and older was 13.9%, comprising about 3.4 million individuals in the USA in 2002. The corresponding values for AD were 9.7% and 2.4 million individuals. Dementia prevalence increased with age, from 5.0% of those aged 71-79 years to 37.4% of those aged 90 and older. CONCLUSIONS: Dementia prevalence estimates from this first nationally representative population-based study of dementia in the USA to include subjects from all regions of the country can provide essential information for effective planning for the impending healthcare needs of the large and increasing number of individuals at risk for dementia as our population ages.

Projected costs of ischemic stroke in the United States.

BACKGROUND: There are barriers to acute stroke care in minority groups as well as a higher incidence of ischemic stroke when compared with non-Hispanic whites. OBJECTIVE: To estimate the future economic burden of stroke in non-Hispanic whites, Hispanics, and African Americans in the United States from 2005 to 2050. METHODS: We used U.S. Census estimates of the race-ethnic group populations age 45 years and older. We obtained stroke epidemiology and service utilization data from the Northern Manhattan Stroke Study and the Brain Attack Surveillance in Corpus Christi project and other published data. We estimated costs directly from Medicare reimbursement or from studies that used Medicare reimbursement. Direct and indirect costs considered included ambulance services, initial hospitalization, rehabilitation, nursing home costs, outpatient clinic visits, drugs, informal caregiving, and potential lost earnings. RESULTS: The total cost of stroke from 2005 to 2050, in 2005 dollars, is projected to be 1.52 trillion dollars for non-Hispanic whites, 313 billion dollars for Hispanics, and 379 billion dollars for African Americans. The per capita cost of stroke estimates are highest in African Americans (25,782 dollars), followed by Hispanics (17,201 dollars), and non-Hispanic whites (15,597 dollars). Loss of earnings is expected to be the highest cost contributor in each race-ethnic group. CONCLUSIONS: The economic burden of stroke in African Americans and Hispanics will be enormous over the next several decades. Further efforts to improve stroke prevention and treatment in these high stroke risk groups are necessary.

A national study of the quantity and cost of informal caregiving for the elderly with stroke.

BACKGROUND: As the US population ages, increased stroke incidence will result in higher stroke-associated costs. Although estimates of direct costs exist, little information is available regarding informal caregiving costs for stroke patients. OBJECTIVE: To determine a nationally representative estimate of the quantity and cost of informal caregiving for stroke. METHODS: The authors used data from the first wave of the Asset and Health Dynamics (AHEAD) Study, a longitudinal study of people over 70, to determine average weekly hours of informal caregiving. Two-part multivariable regression analyses were used to determine the likelihood of receiving informal care and the quantity of caregiving hours for those with stroke, after adjusting for important covariates. Average annual cost for informal caregiving was calculated. RESULTS: Of 7,443 respondents, 656 (8.8%) reported a history of stroke. Of those, 375 (57%) reported stroke-related health problems (SRHP). After adjusting for cormorbid conditions, potential caregiver networks, and sociodemographics, the proportion of persons receiving informal care increased with stroke severity, and there was an association of weekly caregiving hours with stroke +/- SRHP (p < 0.01). Using the median 1999 home health aide wage (8.20 dollars/hour) as the value for family caregiver time, the expected yearly caregiving cost per stroke ranged from 3,500 dollars to 8,200 dollars. Using conservative prevalence estimates from the AHEAD sample (750,000 US elderly patients with stroke but no SRHP and 1 million with stroke and SRHP), this would result in an annual cost of up to 6.1 billion dollars for stroke-related informal caregiving in the United States. CONCLUSIONS: Informal caregiving-associated costs are substantial and should be considered when estimating the cost of stroke treatment.

National estimates of the quantity and cost of informal caregiving for the elderly with dementia.

OBJECTIVE: Caring for the elderly with dementia imposes a substantial burden on family members and likely accounts for more than half of the total cost of dementia for those living in the community. However, most past estimates of this cost were derived from small, nonrepresentative samples. We sought to obtain nationally representative estimates of the time and associated cost of informal caregiving for the elderly with mild, moderate, and severe dementia. DESIGN: Multivariable regression models using data from the 1993 Asset and Health Dynamics Study, a nationally representative survey of people age 70 years or older (N = 7,443). SETTING: National population-based sample of the community-dwelling elderly. MAIN OUTCOME MEASURES: Incremental weekly hours of informal caregiving and incremental cost of caregiver time for those with mild dementia, moderate dementia, and severe dementia, as compared to elderly individuals with normal cognition. Dementia severity was defined using the Telephone Interview for Cognitive Status. RESULTS: After adjusting for sociodemographics, comorbidities, and potential caregiving network, those with normal cognition received an average of 4.6 hours per week of informal care. Those with mild dementia received an additional 8.5 hours per week of informal care compared to those with normal cognition (P < .001), while those with moderate and severe dementia received an additional 17.4 and 41.5 hours (P < .001), respectively. The associated additional yearly cost of informal care per case was 3,630 dollars for mild dementia, 7,420 dollars for moderate dementia, and 17,700 dollars for severe dementia. This represents a national annual cost of more than 18 billion dollars. CONCLUSION: The quantity and associated economic cost of informal caregiving for the elderly with dementia are substantial and increase sharply as cognitive impairment worsens. Physicians caring for elderly individuals with dementia should be mindful of the importance of informal care for the well-being of their patients, as well as the potential for significant burden on those (often elderly) individuals providing the care.

Estimating the cost of informal caregiving for elderly patients with cancer.

PURPOSE: As the United States population ages, the increasing prevalence of cancer is likely to result in higher direct medical and nonmedical costs. Although estimates of the associated direct medical costs exist, very little information is available regarding the prevalence, time, and cost associated with informal caregiving for elderly cancer patients. MATERIALS AND METHODS: To estimate these costs, we used data from the first wave (1993) of the Asset and Health Dynamics (AHEAD) Study, a nationally representative longitudinal survey of people aged 70 or older. Using a multivariable, two-part regression model to control for differences in health and functional status, social support, and sociodemographics, we estimated the probability of receiving informal care, the average weekly number of caregiving hours, and the average annual caregiving cost per case (assuming an average hourly wage of $8.17) for subjects who reported no history of cancer (NC), having a diagnosis of cancer but not receiving treatment for their cancer in the last year (CNT), and having a diagnosis of cancer and receiving treatment in the last year (CT). RESULTS: Of the 7,443 subjects surveyed, 6,422 (86%) reported NC, 718 (10%) reported CNT, and 303 (4%) reported CT. Whereas the adjusted probability of informal caregiving for those respondents reporting NC and CNT was 26%, it was 34% for those reporting CT (P <.05). Those subjects reporting CT received an average of 10.0 hours of informal caregiving per week, as compared with 6.9 and 6.8 hours for those who reported NC and CNT, respectively (P <.05). Accordingly, cancer treatment was associated with an incremental increase of 3.1 hours per week, which translates into an additional average yearly cost of $1,200 per patient and just over $1 billion nationally. CONCLUSION: Informal caregiving costs are substantial and should be considered when estimating the cost of cancer treatment in the elderly.

The explosion in paid home health care in the 1990s: who received the additional services?

OBJECTIVE: Public expenditures for home health care grew rapidly in the 1990s, but it remains unclear to whom the additional services were targeted. This study tests whether the rapidly increasing expenditures were targeted to the elderly with high levels of disability and low levels of social support, 2 groups that have historically been higher users of paid home health and nursing home services. METHODS: The Asset and Health Dynamics Study, a nationally representative, longitudinal survey of people > or = 70 years of age (n = 7,443), was used to determine the association of level of disability and level of social support with the use of paid home care services in both 1993 and 1995. Multivariable regression models were used to adjust for sociodemographics, recent hospital or nursing home admissions, chronic medical conditions, and receipt of informal care from family members. RESULTS: Those with higher levels of disability received more adjusted weekly hours of paid home care in both 1993 and 1995. In 1993, users of paid home care with the least social support (unmarried living alone) received more adjusted weekly hours of care than the unmarried elderly living with others (24 versus 13 hours, P < 0.01) and the married (24 versus 18 hours, P = 0.06). However, by 1995, those who were unmarried and living with others were receiving the most paid home care: 40 versus 26 hours for the unmarried living alone (P < 0.05) and 24 hours for the married (P < 0.05). CONCLUSIONS: The recent large increase in formal home care services went disproportionately to those with greater social support. Home care policy changes in the early 1990s resulted in a shift in the distribution of home care services toward the elderly living with their children.

Gender disparities in the receipt of home care for elderly people with disability in the United States.

CONTEXT: Projected demographic shifts in the US population over the next 50 years will cause families, health care practitioners, and policymakers to confront a marked increase in the number of people with disabilities living in the community. Concerns about the adequacy of community support are particularly salient to women, who make up a disproportionate number of disabled elderly people and who may be particularly vulnerable because they are more likely to live alone with limited financial resources. OBJECTIVE: To address gender differences in receipt of informal and formal home care. DESIGN, SETTING, AND PARTICIPANTS: Nationally representative survey conducted in 1993 among 7443 noninstitutionalized people (4538 women and 2905 men) aged 70 years or older. MAIN OUTCOME MEASURE: Number of hours per week of informal (generally unpaid) and formal (generally paid) home care received by survey participants who reported any activity of daily living (ADL) or instrumental activity of daily living (IADL) impairment (n = 3109) compared by gender and living arrangement and controlling for other factors. RESULTS: Compared with disabled men, disabled women were much more likely to be living alone (45.4% vs 16.8%, P<.001) and much less likely to be living with a spouse (27.8% vs 73.6%, P<.001). Overall, women received fewer hours of informal care per week than men (15.7 hours; 95% confidence interval [CI], 14.5-16.9 vs 21.2 hours; 95% CI, 19. 7-22.8). Married disabled women received many fewer hours per week of informal home care than married disabled men (14.8 hours; 95% CI, 13.7-15.8 vs 26.2 hours; 95% CI, 24.6-27.9). Children (>80% women) were the dominant caregivers for disabled women while wives were the dominant caregivers of disabled men. Gender differences in formal home care were small (2.8 hours for women; 95% CI, 2.5-3.1 vs 2.1 hours for men; 95% CI, 1.7-2.4). CONCLUSION: Large gender disparities appear to exist in the receipt of informal home care for disabled elderly people in the United States, even within married households. Programs providing home care support for disabled elderly people need to consider these large gender disparities and the burden they impose on families when developing intervention strategies in the community.

The potential use of ECG-based prognostic instruments in clinical trials and cost-effectiveness analyses of new therapies in acute cardiac ischemia.

The dramatic improvements in outcomes in acute cardiac ischemia because of therapeutic advances has led to "diminishing returns" with increasingly intensive therapies. This article explores the potential of electrocardiograph (ECG)-based prognostic instruments to identify patients likely to benefit from intense regimens, even in the absence of overall average benefit in the population, with 2 clinical examples: 1) Reperfusion therapy in acute myocardial infarction (AMI); and 2) anticoagulation/antiplatelet therapy in unstable angina. Based on previously developed, ECG-based prognostic instruments we explored the distribution of potential benefits in individual patients from increasingly intense therapy in both AMI and unstable angina. Predictions were obtained on community-based patient samples with both AMI and unstable angina to examine the distribution of effectiveness and cost-effectiveness. For both AMI and unstable angina, much of the benefit of intensifying therapy can be obtained by targeting a subgroup of patients that can be identified in multivariable dimensions by clinical and ECG characteristics. Treatment of these patients with more potent agents (such as hirudin or the glycoprotein inhibitors in unstable angina) is likely to be both effective and cost-effective. However, treatment of "low benefit" patients is unlikely to be effective or cost-effective, and some candidates for therapy are more likely to be harmed, than to benefit, by the more intensive regimens. Multivariable stratification can improve clinical and economic outcomes in acute cardiac ischemia, particularly when such models help identify "high benefit" patients early in their clinical course. Additionally, using validated models in the planning and execution of clinical trials of new therapies can improve the power of the trial and help target the therapies to patients most likely to benefit.

The effect of cost-containment policies on rates of coronary revascularization in California.

BACKGROUND: Lower rates of use of resources have been reported for the treatment of hospitalized patients covered by Medicaid than for privately insured patients. Cost-containment policies may exacerbate such differences in the use of hospital resources. We studied patients with ischemic heart disease who received care at nonfederal hospitals in California in 1983 (the year a Medicaid cost-containment program was implemented), in 1985, or in 1988. Within this sample of patients, we compared the rates of coronary revascularization (coronary-artery bypass surgery or coronary angioplasty) among patients covered by Medicaid, patients with private insurance covering fee-for-service care, and patients enrolled in a health maintenance organization (HMO). METHODS: Logistic-regression models were used to determine adjusted odds ratios for the use of coronary revascularization procedures in patients with different types of insurance, with control for demographic, clinical, and hospital characteristics. The study samples were made up of 49,167 patients in 1983, 47,809 in 1985, and 44,631 in 1988. RESULTS: The frequency of revascularization increased in all three insurance groups from 1983 to 1988, but it did so much faster in the fee-for-service and HMO groups than in the Medicaid group. Patients with private fee-for-service insurance were 1.66 times as likely as Medicaid patients to undergo revascularization in 1983 (P < 0.01), 2.01 times as likely in 1985 (P < 0.01) and 2.33 times as likely in 1988 (P < 0.01). Patients enrolled in HMOs were 0.96 times as likely as Medicaid patients to undergo revascularization in 1983 (P < 0.05), 1.23 times as likely in 1985 (P < 0.01), and 1.53 times as likely in 1988 (P < 0.01). CONCLUSIONS: The frequency of coronary revascularization in California in 1983 was nearly twice as high for patients with private fee-for-service insurance as for patients enrolled in HMOs or for Medicaid recipients. The implementation that year of stringent cost-control measures by Medicaid may explain the slower increase in the frequency of revascularization over five year among Medicaid recipients as compared with patients in the fee-for-service and HMO groups. Different incentives in fee-for-service and HMO practice may explain the lower frequency of revascularization among patients enrolled in HMOs, although the rates of increase for these two groups were about the same from 1983 to 1988.