Influence of Comorbidities and Socioeconomic Factors on the Association Between Anemia and Mortality in Adults with Heart Failure: A Population Based Study
Objective: The objective of this dissertation was to examine the effects of biological (comorbidities) and non-biological (socioeconomic status, SES) factors on the association between anemia and mortality in adults with heart failure (HF) using a nationally representative population-based data. Five highly prevalent and serious comorbidities, namely coronary artery disease (CAD), chronic kidney disease (CKD), chronic obstructive pulmonary disease (COPD), hypertension and diabetes, were selected and their modifying effect on the association between anemia and mortality in adults with HF determined. Also, the excess risk due to socioeconomic factors such as health insurance, education level and family income on the association between anemia and mortality was calculated. Methods: This was a retrospective cohort study using the population-based National Health and Nutrition Examination Survey (NHANES) survey data from 1999-2010. Our cohort was made up of subjects who self-reported as having been diagnosed with HF and specific comorbidities (hypertension, CAD, COPD, CKD, and diabetes). Demographic, clinical and laboratory variables collected from survey participants were used for analysis. Of the 62,160 subjects included in NHANES during the study period, only participants who provided self-reported data and health measurements at the mobile examination center (MEC) (n=59,367) were selected. After applying all inclusion and exclusion criteria, the final sample size was 926. We conducted multiple Cox regression analysis to estimate the relative risk of mortality using anemia as the main exposure variable. Further analysis examined the interaction between anemia and specific-comorbidities on the additive and multiplicative scales. Also, the excess risk of mortality attributable to socioeconomic factor was derived. Results: The study sample included 926 subjects who self-reported they had been diagnosed with HF. The prevalence of anemia in the cohort was 23%, whereas the overall crude mortality rate was 40%. Findings suggest significant modifying effects of Diabetes the additive scale; indicating the effect of diabetes and anemia on mortality is greater than the sum of the effect of these exposures and anemia taken separately. We did not observe excess additive risk of mortality for any other comorbidities along with anemia. Also, none of the comorbidities studied revealed any meaningful modifying effects on the multiplicative scale. Furthermore, the joint effect of anemia with family annual income, and anemia with health insurance type were significantly associated with the risk of mortality in adults with HF. Conclusion: Select comorbidities modify the association between anemia and mortality in HF on additive and multiplicative scales, albeit in different directions. Greater focus should be given to the treatment of patients with anemia in HF coexisting with diabetes, to achieve improved survival outcomes. In addition, mortality in HF varied by income group or health insurance type. Therefore standardizing clinical care for HF patients irrespective of income or health insurance type will reduce the disparities along socioeconomic status in HF population.
Umejiego, Johnbosco Chukwuma, "Influence of Comorbidities and Socioeconomic Factors on the Association Between Anemia and Mortality in Adults with Heart Failure: A Population Based Study" (2018). Texas Medical Center Dissertations (via ProQuest). AAI10930840.