Rural areas in the U.S. have higher age-adjusted death rates for heart disease, stroke, cancer, unintentional injury and chronic lower respiratory disease than metropolitan areas, according to a Centers for Disease Control and Prevention (CDC) report.

Those five diseases were the leading causes of death in rural and metropolitan areas from 1999 to 2014, which was the time period the authors analyzed.

The document was published online Jan. 13 as part of the CDC’s morbidity and mortality weekly report.

The authors mentioned that approximately 15 percent of the U.S. population lives in rural areas, which have higher rates of cigarette smoking, hypertension, obesity and physical inactivity during leisure time compared with metropolitan areas. In 2014, 18.1 percent of rural residents and 15.1 percent of metropolitan residents lived in poverty. People living in rural areas also often have less access to quality healthcare.

The analysis found that from 1999 to 2014, the annual age-adjusted death rates for heart disease, stroke, cancer, unintentional injury and chronic lower respiratory disease were lower in metropolitan areas than in rural areas. The annual age-adjusted death rates for heart disease and stroke decreased in both rural and metropolitan areas, although the rate of decrease for heart disease was slower in rural areas. The rates of decreases for stroke were similar in both areas.

The authors also found that the numbers of potentially excess deaths in rural areas decreased an average of 2.7 percent per year for cancer, increased an average of 3.2 percent per year for chronic lower respiratory disease and remained stable for heart disease, stroke and unintentional injury.

The authors defined potentially excess deaths as deaths among people younger than 80 years old that exceed the numbers that would be expected if the death rates of states with the lowest rates occurred in every state. They used the three states with the lowest rates for each cause of death from 2008 to 2010 as the benchmark states.

In 2014, the numbers of potentially excess deaths among adults younger than 80 years old were 25,278 from heart disease, 19,055 from cancer, 12,165 from unintentional injury, 10,676 from chronic lower respiratory disease and 4,108 from stroke.

For all five causes of death, rural areas had a higher percentage of deaths categorized as potentially excess deaths. For instance, in 2014, 42.6 percent of heart disease deaths in rural areas and 27.8 percent of heart disease deaths in metropolitan areas were classified as potentially excess deaths.

The CDC said it is working on reducing the rates of smoking and obesity, both of which are risk factors that contribute to an increased risk for heart disease, stroke, chronic lower respiratory disease and cancer. The agency is also working to increase access to cancer screening and cardiovascular risk reduction, which could help people living in rural areas.

The authors mentioned a few limitations of the study, including that age-adjusted rates do not represent actual deaths. They also calculated standard errors of estimates of potentially excess deaths using a conservative method. In addition, they used the same three states as benchmarks for rural and metropolitan areas. Further, they used data from 2008 to 2010 to estimate potentially excess deaths, which did not reflect potential progress made in future years.

“Routine tracking of potentially excess deaths from the five leading causes of death in nonmetropolitan and metropolitan areas might help public health officials monitor important rural health disparities and select effective programs and policies to improve the health of residents of rural areas,” the authors wrote. “Additional information on potentially excess deaths might be used to evaluate the success of public health interventions and to help determine where to allocate resources in areas with the greatest need. State and local public health officials in rural areas might seek advice from officials in rural areas with fewer potentially excess deaths for ways to reduce mortality in their jurisdictions or increase coordination with urban areas to ensure rural residents have timely access to specialized services.”