Researchers say it is our ability to fight off major killers such as heart disease and stroke that may be contributing to the overall decline in death rates.
"Over the past few decades, mortality reductions are generally due to better medical care -- especially for heart disease, prevention [such as] earlier cancer detection," said David Cutler, professor of Economics at Harvard University. Behavioral changes such as reductions in the number of smokers also played a major role.
Part of the decline can also be contributed to declines in infant mortality, Meara said, considering "substantial and impressive improvement in recent years…[in] technology and preventing death in premature infants."
Meara said this data is consistent with other research suggesting that areas where there has been a lot of health care spending growth over time, such as infant health and cardiovascular disease, "are the areas where we are seeing significant improvement in terms of reduction in death."
"The bigger-picture issue [here] is that the things affecting death rates are a combination of factors both environmental and medical," Meara says, and these factors will change as the burden of disease changes.
"As you get better at preventing death from some diseases, such as heart disease and stroke, it's natural that the importance of other diseases, such as cancer, will increase."