This story is part of a partnership between MedPage Today and VICE News.
The 2015 death rate in the United States was higher than the year before it for the first time in a decade, but it's too soon to know whether it's a coincidence or something worse: the start of a trend.
The 2015 death rate was 729.5 deaths per 100,000 people, up from 723.2 deaths per 100,000 people in 2014, according to new data from the Centers for Disease Control's National Center for Health Statistics. The death rates have been age-adjusted to account for the fact that as people age, their risk of death increases.
"It hasn't happened in a while, so we are curious to look into what is going on," said Farida Ahmad, the mortality surveillance lead researcher at the Centers for Disease Control's National Center for Health Statistics, adding that the 2015 death rate still isn't as high as it was in 2013 when it reached 731.9 deaths per 100,000 people. "But there are not alarm bells. We don't know if this is a trend."
Ahmad cautioned that this is preliminary data, and her team hasn't yet drilled down into demographics, such as race, gender and socioeconomic status. Final data will be published in December.
The last two times the death rate rose, in 2005 and in 1999, it only did so for one year, Ahmad said, stressing that it's too soon to know what will happen in 2016.
Death rates for all causes of death except cancers and HIV increased between 2014 and 2015, but rates for Alzheimer's disease, firearms and overdose increased the most between those years. Although the cancer death rate went down somewhat, cancer is still a leading cause of death, second to only heart disease, according to the CDC.
Heart disease deaths have been declining since 1993 but didn't do so this year, Ahmad said. Instead, the rate stayed roughly the same, edging up only slightly.
Ahmad said many of the smaller causes of deaths have been increasing over the years while the overall rate declined. She wondered whether they they were perhaps offset by the steady decline in heart disease deaths. Since the heart disease death rate didn't decline this year, Ahmad speculated that it may have helped the smaller causes of death drive the overall rate up.
"There's not one specific cause," Ahmad said of the increased death rate. "It's a combination of factors…There are 12 causes of death that have shown increases. And any one of those probably is not enough to make that big of a difference."
Since opioid epidemic casualties are so numerous that they're increasing organ donation, it's no surprise to addiction specialists like Dr. Joshua Lee, of NYU Langone Medical Center, that the overdose death rate increased in 2015.
"On average, things have been going up and getting worse over the last 10 years," Lee said. "We're still dealing with a really big problem and only now seeing a big time coordinated federal response."
Dr. Roy Buchinsky, of UH Case Medical Center in Ohio, said the increased death rate may or may not be a fluke, but it's still a wake-up call for physicians to start discussing the three pillars of lifestyle medicine to their patients: nutrition, physical activity and sleep.
"We know from data — from sound scientific data — how lifestyle affects almost every single thing from cardiovascular disease to cancer to Alzheimer's to inflammation to arthritis," Buchinsky said. We should be "getting the message out that we truly have an opportunity here to control our destiny in many, many ways."
Although Ahmad's team hasn't compared the United States' death rate to those in other countries, it's worth noting that, according to CIA estimates for 2015, the United States' death rate is lower than the death rates in the United Kingdom and 91 other countries.