Circ: Pulse of a nation's economy linked to cholesterol rates
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The study by Lakshmi Venkitachalam, PhD, of the University of Missouri-Kansas City School of Medicine in Kansas City, and colleagues expands beyond research that has explored the relationship between patient- and physician-level factors and variations in elevated cholesterol levels to investigate country-level factors. The team focused on a variety of economic and health system indices.
“In an effort to guide the National Heart, Lung and Blood Institute in setting priorities for investment in global cardiovascular health, the Institute of Medicine recently outlined key barriers to and evidence-based solutions for the control of cardiovascular disease across the world,” Venkitachalam et al wrote in explanation of the study. “An improved understanding of the relationship between levels of national economic development, healthcare investment, health system characteristics, and key modifiable cardiovascular risk factors may provide insights for the prioritization of cardiovascular disease prevention programs.”
Using the international REACH (Reduction of Atherothrombosis for Continued Health) Registry, the researchers obtained data on 53,570 outpatients from 36 countries enrolled between 2003 and 2004. As part of the registry, the patients were at risk of atherothrombosis from established coronary artery disease, cerebrovascular disease, peripheral artery disease or three or more risk factors for cardiovascular disease. The data included total cholesterol values and any history of hyperlipidemia. Elevated cholesterol was defined as 200 mg/dL or greater.
For country level indices, they selected gross national income; total expenditure on health as percentage of gross domestic product; government expenditure on health as percentage of total expenditure on health; out-of-pocket expenditures as percentage of private expenditure on health; and the World Health Organization (WHO) indices of health system achievement and performance/efficiency. They used hierarchical models to study the relationships between country-level factors and elevated cholesterol levels.
They found that 38 percent of the patients had elevated cholesterol levels, with prevalence ranging from 73 percent in Bulgaria to 24 percent in Finland. Of those patients with a history of hyperlipidemia, 37 percent had elevated cholesterol, while among those with no such history, 34 percent had elevated cholesterol.
Overall, 9.3 percent of the variability in elevated cholesterol was at the country level. The proportion was higher among patients with a history of hyperlipidemia, at 12.1 percent, compared with those without a history, at 7.4 percent.
They noted a high prevalence of elevated cholesterol in patients from the Eastern European countries of Bulgaria, Lithuania, Romania, Ukraine, Hungary and Russia, countries that also ranked relatively low on health system and economic indices. They found a relatively low prevalence of elevated cholesterol in Finland, the U.K., Israel, Australia and Canada, all of which had considerably lower total expenditure on health as percentage of gross domestic product (GDP) and comparable or slightly more favorable WHO health system indices. The U.S. also ranked relatively low in prevalence of elevated cholesterol but not on factors such as total expenditure on health as percentage of GDP.
“We found that patients living in countries in the highest third of gross national income or WHO health system achievement and performance/efficiency indices had a significantly lower likelihood of having elevated total cholesterol levels than patients from countries falling in the lower two-thirds,” co-author Elizabeth A. Magnuson, ScD, director of the Health Economics and Technology Assessment at Saint Luke’s Mid America Heart Institute in Kansas City, said in a statement. “Patients from countries falling within the highest third of all countries studied for out-of-pocket health expenditures were more likely to have elevated total cholesterol than patients who had lower out-of-pocket costs.”
The authors emphasized that REACH was an observational database and cautioned against assuming causal relationships from their findings. REACH recruited patients with access to healthcare, so their results may underestimate the prevalence of elevated cholesterol in some countries and may not be generalizable to people without access to healthcare.
They pointed out that healthcare providers have made inroads in efforts to control cardiovascular risk factors such as high cholesterol, but that many of these achievements have been in high-income countries. They added that many factors may influence outcomes.
“Optimal management of cardiovascular disease is complex, and country-level variation in rates of elevated cholesterol may be due to differences in clinical guidelines, as well as whether and the extent to which guidelines are followed and specific initiatives are effectively implemented,” Magnuson said. “The association between high cholesterol and out-of-pocket healthcare expenses may reflect an inability or unwillingness for patients in countries with higher out-of-pocket expenses to be compliant with prescribed medications. The recent availability of generic cholesterol-lowering therapy should make out-of-pocket expense less of a barrier.”
The authors proposed that programs under WHO that have been designed to help less affluent nations prevent and control high cholesterol levels as well as efforts such as the Million Hearts initiative in the U.S. may serve as templates for other countries. They concluded that their results may help to strengthen control and prevention efforts globally as well as inform national health policies.