In the U.S. and comparable countries there has been a reduction in disease burden, as measured by Disability Adjusted Life Years (or DALYs), in recent years. Our latest chart collection, which analyzes data from the Institute for Health Metrics and Evaluation, shows that while disease burden has declined in the U.S. and comparable countries since 1990, the U.S. continues to have higher age-adjusted disease burden rates than those of comparable countries. (We define comparable countries as those that are similarly sizable and wealthy, and specifically include OECD member countries with above average GDP and GDP per capita in at least one of the past 10 years.) Since 1990, the disease burden rate has dropped by 14% in the U.S., while comparable countries have seen an average decrease of 18% (ranging from a 15% decline in Canada to a 23% drop in Germany).The U.S. has highest rate of disease burden among comparable countries, and the gap is growing Click To Tweet
A DALY is a measure of disease burden that takes into account years of life lost due to premature death as well as years of productive life lost to poor health or disability. DALYs provide important information that isn’t found when looking at mortality rates. As a measure of the health of the population, mortality statistics only tell us about the extent to which diseases lead to death and do not show the burden of disease that arises from disabilities that may not ultimately cause death. Unlike DALYs, mortality rates also do not account for age at the time of death.
In the U.S. in 2010, the leading causes of DALYs were mental health conditions, circulatory conditions, cancers, and musculoskeletal disorders. Over time, the diseases that cause the most DALYs in the U.S. have changed. In 1990, circulatory illnesses were the leading cause, but have since declined significantly, particularly driven by a reduction in the years of life lost from coronary heart disease (which includes angina and heart attack). DALYs caused by injuries – particularly from car accidents – have also decreased significantly since 1990, as have DALYs from cancers (including lung, breast, and colon). For each of the disease categories with improvements, the improvement seen after adjusting for age has come primarily from a reduction in the years of life lost (as opposed to a reduction in the year lived with disability).
Other countries have seen improvements in similar areas – circulatory conditions, cancer, and injuries –but at faster rates on average. From 1990 to 2010, the U.S. had below-average improvements in age-adjusted disease burden caused by circulatory conditions (-36% vs. -44% in comparable countries on average), cancer (-20% vs. -21%), injuries (-20% vs. -25%), and neonatal conditions (-32% vs. -39%). Rates of improvement for specific conditions, of course, vary by country. For example, Germany, which saw the most improvement in overall age-adjusted DALYs among comparable countries, has improved its DALY rate from coronary heart disease by 50% since 1990, compared to the U.S.’s 43% improvement over the same time period. Age-adjusted DALYs from car accidents dropped by 45% in Germany from 1990 to 2010, compared to the U.S.’s drop of 30%.
In assessing how health outcomes have changed and making judgements about where to target health resources, DALYs provide a more complete picture of the burden of disease than mortality rates. Of course, many socioeconomic and behavioral factors outside of the control of the health system may affect changes in mortality and disability.