Trendspotting: Chronic Pain Keeps Rising

NewsWire: 6/07/21

• According to a new study, the prevalence of chronic pain increased substantially among Americans from 2002 to 2018. The increase occurred among people of all ages and backgrounds, but was steeper among those who are lower-income and less educated. (Demography)
• NH: Are you experiencing a specific type of pain that has lasted at least three months? If so, you're not alone.
• Just over half (54%) of all Americans in 2018 said they are experiencing such pain, up from just under half (49%) in 2002. The most common type of chronic pain reported was "joint pain," and it's here where the incidence rose the fastest, from 27% to 33% of all Americans. Other types of pain were back, neck, headache/migraine, and facial/jaw.  Even after adjusting for age, the increases are still substantial. For any pain the age-normalized rate rose by 8%, and for joint pain it rose by 14%.
• These are the findings of an analysis of data from the National Health Interview Survey (NHIS), now run by the NCHS. The sample size here is enormous: roughly 20K-30K respondents per year, for a total N = 443,000. And the data allow for matching to nearly every relevant socioeconomic variable. The Demography editors believe the study is so important that they stretched the boundaries of their discipline to publish it.
• Why study chronic pain? Because, the researchers point out, it's a major public health problem given its high prevalence and costs. "Nationally, the number of people experiencing chronic pain exceeds those affected by heart disease, cancer, and diabetes combined. In 2012, the annual economic cost of pain in the United States was estimated at more than $600 billion and has likely in­creased since then. For in­di­vid­u­als, chronic pain is a key de­ter­mi­nant of qual­ity of life, healthcare utilization, and disability." What's more, every previous study of chronic pain has shown that its prevalence has been rising over time.
• Many of the study's findings corroborate what we already know. In every age bracket, women are much more likely to report chronic pain than men. Whites are more likely than nonwhites. The poor and less educated are more likely than the affluent and more educated. And of course older people are more likely than younger people. As expected, alcohol use, smoking, higher BMI, less exercise, and most reported health conditions are also associated with higher rates of chronic pain.
• What's surprising is how steep and widespread the rising prevalence is over time. In literally every single crosstab--by age, region, nativity, educational attainment, and income--rates of chronic pain have risen. Here's the prevalence for "any pain" by age and sex.

• Any good news? Well, some. In most age brackets, the population composition has shifted in ways that favor lower rates of chronic pain. For example, Americans smoke less and therefore have fewer respiratory complaints. They are a bit more affluent and educated overall. According to their self-reports, they engage in somewhat more physical activity. Among the 65+ bracket, they report fewer heart conditions.
• Unfortunately, all these positives are overwhelmed by negatives--that is, by behaviors or conditions strongly associated with chronic pain. Among all age brackets (25-44, 45-64, and 65+), rising shares of Americans report high BMIs, hypertension, diabetes, and drinking excessively. Emotional distress is highly and positively correlated with chronic pain, and among the two younger age brackets, rates of emotional distress have risen. Marriage and homeownership rates are negatively correlated with chronic pain, and of course these rates have fallen among the nonelderly.
• Because of the study's vast N-size, the researchers are able to regress chronic pain over a large number of independent variables with respectable accuracy. Here they summarize the normalized impact of the change in each variable over the 2002-2018 period on the chronic pain rate for each age group.

• Note the adverse effect of rising BMI and rising alcohol use in every age bracket. Note especially the impact of soaring emotional distress rates among the nonelderly. For the youngest (Xer and Millennial) age group, rising emotional distress accounts for half of the entire rise in chronic pain. At age 45 and over, a rise in "arthritis" (self-reported after a visit to a doctor) also plays an important role--recall the importance of "joint pain."
• Needless to say, the report's bottom line suggests that Americans may not be getting their money's worth from a healthcare system that spends vastly more per capita than any other on earth--and that has grown 50% faster than our economy over the past 30 years. Not only has our life expectancy actually retrogressed during most of the last decade (see "2020 Demography Review: United States"), but now it turns out that rates of chronic pain are rising among those of us who are alive.
• To be sure, any study of change in the prevalence of self-reported pain, no matter how accurate, opens itself to the question: How much of the change is subjective or perceptual (the term of art is "psychosomatic" or "psychogenic") and thus beyond the reach of conventional healthcare professionals? Could it be that, with the passage of time or with the turnover of generations, people tend to report conditions that earlier would have gone unreported?
• Such questions are, strictly speaking, unanswerable. If people are more aware of their pain, it's possible that the U.S. healthcare system itself may have played a role in this heightened awareness. Back in the 1990s and 2000s, government task forces, with the strong encouragement of Big Pharma, actively encouraged providers to tell patients they had a "right" to be treated for pain ("the fifth vital sign," as it was dubbed back then). Many have since blamed the prescription opioid epidemic on this total war on pain.
• Today, the prescription epidemic is over (even while the death toll from illegal opioids still rises), and we know that opioids are not a safe or effective treatment for most cases of chronic pain. Perhaps, though, Americans as a whole now have higher expectations than before about controlling pain. And perhaps for that reason they are more likely to self-report something they think a provider can do something about.
• All this is possible. It's difficult to evaluate subjective self reports against an objective standard.
• But IMO most of what we're seeing with these rising rates of chronic pain does constitute a genuine health problem. To begin with, while surging provider fixation on pain monitoring (along with the over-prescribing of opioids) has been pretty much a uniquely American phenomenon, rising pain has not been. The self-reported prevalence of chronic pain has been rising throughout the developed world.
• More importantly, as we pointed out above, most of the drivers accounting for the rising incidence of chronic pain in the Demography study are non-attitudinal--like more alcohol abuse and rising rates of obesity, diabetes, and hypertension. We know from plenty of other data sources that they're happening.
• For the two older age brackets, rising rates of arthritis appear to be a key driver. Arthritis, even when diagnosed by a physician, could be a squishy indicator: Are these rises real (that is, backed by physical evidence) or are they perceptual? According to one ingenious new study that compares physical evidence of osteoarthritis in cadavers over time, the age-adjusted rise--for knee arthritis, anyway--is backed by physical evidence.
• As for the youngest two age brackets, we noticed that one big driver was a rising rate of emotional distress. Again, this is a trend for which we have plenty of independent evidence. (See "Millennials' Mental Health Struggles Go Beyond Finances," and "Indicators of Despair Rising Among Adults in Their 30s and 40s.") Americans in all age brackets are not feeling very upbeat these days ("America Is Registering Record Levels of Unhappiness."), but younger Americans more than most. Emotional distress does indeed predispose people toward chronic pain. This fact is well documented in the medical literature and demonstrated, cross-sectionally each year, in the Demography study itself.
• All this has big implications for healthcare providers. At the very least, they need to devise safer and more effective treatments for chronic pain.  And if they want to go further and address the lifestyle and emotional issues causing their patients' chronic pain, well, they have my blessing. But this is a challenge that may require them to remake the medical paradigm that most of them have spent a lifetime training for.