Epidemiology of Functional Status in Elderly Hispanics

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Investigator: Mary N. Haan, DrPH, MPH
Sponsor: NIH National Institute on Aging

Location(s): United States

Description

Aging cohorts suffer from informative censoring due to competing risks of death, selective non- mortality attrition, as well as time dependent changes in exposure. Multiple interdependent exposures and outcomes are little studied in relation to health disparities. Death is undeniably a major force shaping patterns of change in risk factors and disease risk in older populations. Increasing interactions of multiple conditions over time complicate analysis. These processes differentially affect race/ethnic health disparities because, among disadvantaged populations, exposures to risk factors typically are higher, start earlier in life, are more sustained and more often under/untreated. Race/ethnic comparisons of risk that do not account for competing risk are likely to incorrectly estimate the impact of treatment or prevention on disease. Mexican Americans have higher prevalence of diabetes, obesity, and metabolic syndrome at younger ages compared to non-Hispanic whites (NHW). Most older people in this high risk ethnic group have experienced lifelong poverty, low education, and hazardous occupations. As such, compared to non-Hispanic whites, they are at higher risk for stroke, dementia, and cognitive and functional impairments and have poorer survival so competing risk of death is likely to be a major issue in analysis. Policy and intervention. Our study has implications for treatment and prevention policies for health and social services. Success in delaying death may mean survivors with more severe disease who are at higher risk for multiple impairments that especially impact disadvantaged Americans. Increases in obesity, metabolic syndrome, and type 2 diabetes in younger people are projected to lead to future increases in late life impairment The Sacramento Area Latino Study on Aging was followed from 1998 to the present. Study Aims are: AIM 1.0.Type 2 diabetes is simultaneously associated with increased risk of cognitive and functional decline, stroke, dementia and death. Statistical methods that account for competing risk of death will produce lower and less biased estimates of these associations than in traditional models. AIM 2.0.Hypertension is simultaneously associated with the increased risk of cognitive and functional decline, stroke, dementia and death. The association of HTN with nonfatal outcomes is influenced by competing risk (CRisk) of death. Statistical methods that account for competing risk of death will produce lower and less biased estimates of these associations than traditional models provide. AIM 3.0: Comorbidity is cumulative over time and is simultaneously associated with the multiple outcomes of greater cognitive and functional decline, and dementia and death. Simultaneous joint modeling of time dependent comorbidities with multiple outcomes accounting for informative censoring will provide important information about the underlying syndrome comprised by these conditions and improve statistical efficiency. This study will examine the effects of high mortality rates on the association between type 2 diabetes or hypertension on cognitive decline, stroke, dementia and functional impairments in aging Mexican Americans.