@article {999, title = {Pancreatic beta-cell function as a predictor of cardiovascular outcomes and costs: findings from the Cardiovascular Health Study.}, journal = {Curr Med Res Opin}, volume = {24}, year = {2008}, month = {2008 Jan}, pages = {41-50}, abstract = {

OBJECTIVE: To explore relationships between beta-cell function and incident cardiovascular events, death, and medical costs among elderly individuals.

RESEARCH DESIGN AND METHODS: In a prospective, population-based cohort of 4555 elderly individuals, we examined the effect of beta-cell function on incident cardiovascular events and mortality. We also examined costs for 3715 of these individuals. We used the computer-based homeostasis model assessment (HOMA) to calculate indices of beta-cell function (HOMA-\%B) and insulin sensitivity (HOMA-\%S) using baseline fasting glucose and insulin levels. All subjects were followed from 1992/1993 for 6 years or until death.

MAIN OUTCOME MEASURES: Discrete-time survival model of the effects of beta-cell function on incident cardiovascular events and all-cause mortality; and semiparametric estimators for calculations of mean 6-year costs.

RESULTS: Controlling for HOMA-\%S, a 20\% decrease in HOMA-\%B was associated with increased odds of incident cardiovascular events (odds ratio [OR], 1.09; 95\% confidence interval [CI], 1.05-1.14) and death (OR, 1.10; 95\% CI, 1.07-1.14). The relationships persisted after controlling for clinical and sociodemographic confounders. A 20\% decrease in HOMA-\%B was also associated with increased costs (cost ratio, 1.03; 95\% CI, 1.01-1.05). The significant association did not persist after controlling for confounders.

LIMITATIONS: The sample comprises relatively healthy elderly individuals and is based on data from 1992 through 1999, which may not reflect current experience. The measure of beta-cell function is an estimate generated from single measures of glucose and insulin.

CONCLUSIONS: Beta-cell function as measured by HOMA-\%B is a significant predictor of incident cardiovascular events and mortality but not of costs, controlling for HOMA-\%S and sociodemographic and clinical confounders.

}, keywords = {Aged, Aged, 80 and over, Cardiovascular Diseases, Cohort Studies, Coronary Disease, Female, Follow-Up Studies, Health Care Costs, Heart Failure, Humans, Insulin-Secreting Cells, Male, Myocardial Infarction, Outcome Assessment, Health Care, Prognosis, Prospective Studies, Stroke}, issn = {1473-4877}, doi = {10.1185/030079908x253573}, author = {Curtis, Lesley H and Hammill, Bradley G and Bethel, M Angelyn and Anstrom, Kevin J and Liao, Lawrence and Gottdiener, John S and Schulman, Kevin A} } @article {1113, title = {External validity of the cardiovascular health study: a comparison with the Medicare population.}, journal = {Med Care}, volume = {47}, year = {2009}, month = {2009 Aug}, pages = {916-23}, abstract = {

BACKGROUND: The Cardiovascular Health Study (CHS), a population-based prospective cohort study, has been used to identify major risk factors associated with cardiovascular disease and stroke in the elderly.

OBJECTIVE: To assess the external validity of the CHS.

RESEARCH DESIGN: Comparison of the CHS cohort to a national cohort of Medicare beneficiaries and to Medicare beneficiaries residing in the CHS geographic regions.

SUBJECTS: CHS participants and a 5\% sample of Medicare beneficiaries.

MEASURES: Demographic and administrative characteristics, comorbid conditions, resource use, and mortality.

RESULTS: Compared with both Medicare cohorts, the CHS cohort was older and included more men and African American participants. CHS participants were more likely to be enrolled in Medicare managed care than beneficiaries in the national Medicare cohort. Compared with the Medicare cohorts, mortality in the CHS was more than 40\% lower at 1 year, approximately 25\% lower at 5 years, and approximately 15\% lower at 10 years. There were minimal differences in comorbid conditions and health care resource use.

CONCLUSION: The CHS cohort is comparable with the Medicare population, particularly with regard to comorbid conditions and resource use, but had lower mortality. The difference in mortality may reflect the CHS recruitment strategy or volunteer bias. These findings suggest it may not be appropriate to project absolute rates of disease and outcomes based on CHS data to the entire Medicare population. However, there is no reason to expect that the relative risks associated with physiologic processes identified by CHS data would differ for nonparticipants.

}, keywords = {Aged, Cardiovascular Diseases, Cohort Studies, Comorbidity, Female, Humans, Male, Medicare, Randomized Controlled Trials as Topic, Reproducibility of Results, Socioeconomic Factors, United States}, issn = {1537-1948}, doi = {10.1097/MLR.0b013e318197b104}, author = {DiMartino, Lisa D and Hammill, Bradley G and Curtis, Lesley H and Gottdiener, John S and Manolio, Teri A and Powe, Neil R and Schulman, Kevin A} }