People don't feel pain the same way.
Instead, chronic pain is experienced differently from person to person for different reasons, from sex and educational level to wealth and race, according to a University at Buffalo study that confirms some known social disparities and reveals other new ones.
Among its findings: People with the least education are 80 percent more likely to report any pain, from mild to severe, than those with the highest educational level. The difference is even starker for severe pain. Individuals who didn’t finish high school are 370 percent more likely to experience severe chronic pain than those with graduate degrees.
The study's author, Hanna Grol-Prokopczyk, said the key takeaways are the striking disparities in people's experience of pain and its prevalence, complicating efforts to find a balance between treating pain adequately in the face of the epidemic of overdoses and deaths nationwide caused by opioid painkillers.
“There are a lot of pressures right now to reduce opioid prescriptions,” Grol-Prokopczyk said. “In part, this study should be a reminder that many people are legitimately suffering from pain. Health care providers shouldn’t assume that someone who shows up in their office complaining of pain is just trying to get an opioid prescription."
Grol-Prokopczyk urged further research to help explain the disparities and their potential causes, such as obesity, job characteristics, and health insurance status.
The analysis, published in the journal Pain, is based on 12 years of data from more than 19,000 people age 51 and older with non-cancer pain surveyed every two years from 1998 to 2010 by the University of Michigan for the National Institute of Aging.
The results show that poorer individuals are more likely to report pain, and that chronic pain levels are rising over time, as well as by age, meaning people who were in their 60s in 2010 reported more pain than people who were in their 60s in 1998.
Most studies of pain ask individuals whether or not they experience pain. This one also examined social disparities and degree of pain -- mild, moderate or severe -- as it followed the survey respondents over the years.
The socioeconomically disadvantaged are much more likely to report experiencing severe pain, according to the study. That stands in contrast to another finding: Poorer, less-educated individuals are more likely to be using opioid painkillers.
"The reason is not clear, but we do know that opioids can increase sensitivity to pain over time," said Grol-Prokopczyk, an assistant professor of sociology.
Overall, the study found that, over the 12 years, females, the least wealthy and the poorest educated are more likely to report pain than males, the wealthiest and most educated. Reported pain also was a good predictor of later disability or death.
On race, Hispanics are more likely to report experiencing any degree of pain than whites or blacks, but blacks are more likely to report severe pain. However, when Grol-Prokopczyk controlled for education and wealth, she found that African-Americans report experiencing less pain than whites, and that Hispanics have about the same pain scores as whites. In other words, among whites and blacks with the same socioeconomic status, blacks are less likely to report being in pain.
How much pain is there in the United States? A 2015 analysis of data from the 2012 National Health Interview Survey found that an estimated 25.3 million adults, 11.2 percent, experience chronic pain, meaning pain every day for the preceding three months. Nearly 40 million adults, 17.6 percent, reported experiencing severe levels of pain.