Prevalence of Chronic Pain Increasing

By Lynn Webster, MD, PNN Columnist

According to the Centers for Disease Control and Prevention, opioid prescribing quadrupled from 1999 to 2010. Some policymakers suggest that the amount prescribed in 1999 was appropriate and should remain static, and that any prescribing above the 1999 level exceeds the amount required to meet the needs of people in pain.

Perhaps, but it is important to understand that pain was vastly undertreated in the 1990s and there was a clear need to find effective treatment for pain patients. At least some of the increase in opioid prescribing would also seem logical, based on the greater number of people in pain.

According to the National Institutes of Health (NIH), the number of American adults suffering from at least one painful condition increased substantially from 120.2 million in 1997 to 178 million in 2014 – about 41 percent of the adult population. These numbers are from a comprehensive analysis of 18-year trends in the rates of noncancer pain, recently published in the Journal of Pain. 

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 Aging Population

The NIH report may make you wonder why there are more people in pain now than there were in 1999. Here are some possible explanations.

Our aging population includes an ever-increasing number of elderly people. Baby boomers, who make up the largest demographic of society, recently began to enter their 70s. That is the decade during which we begin to experience a much greater prevalence of arthritis, spinal pain, obesity, surgical operations and cancer.

Mortality rates for cancer continue to decline, thanks to better treatments. More than 40% of cancer survivors now live longer than 10 years. That is good, of course, but many cancer survivors experience treatment-related chronic pain. 

Aging increases the likelihood that people will experience chronic pain. More than half of all adults older than 65 experience arthritic pain of the spine and other joints. For more age-related statistics regarding arthritis, click on this U.S. government PubMed abstract, the CDC's arthritis information page or the Arthritis Foundation’s website.  

In all age groups, the U.S. has an obesity epidemic (according to the CDC and the Journal of the American Medical Association) which can lead to diabetes. Obesity causes increased load on the back and joints, causing chronic pain. In addition, more people have peripheral neuropathy caused by diabetes. 

Finally, there is the problem of chronic post-surgical pain, which we began to recognize around the turn of the century. The incidence of chronic pain after major surgery is estimated to lie between 20% and 50%. Relatively minor operations, such as inguinal hernia repair or a C-section, seem to lead to this problem in approximately 10% of patients. This is an annuity that will keep growing as more operations occur every year.  

The increased prevalence of chronic pain has probably contributed to a greater number of opioid prescriptions. In addition, we have historically failed to recognize that pain deserves to be treated.

Alternative therapies like massage and acupuncture have not been widely available due to lack of insurance coverage. Thus, many people in chronic pain have not had access to any therapy except opioids. This can partially explain why there was an increase in the amount of opioids prescribed from 2001 to 2014.  

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Undertreated Pain

Quadrupling the amount of opioids prescribed over several decades may sound excessive, unless we consider the growing number of people who were undertreated and in severe pain, year after year.  

Additionally, we must recognize opioids have not been distributed equally. It is possible that more opioids have been prescribed than appropriate for some patient populations, while other patients have been denied access to any pain treatment. 

A major shift in opioid prescribing began several years ago and by all accounts is accelerating. Between 2013 and 2017, the amount of opioids prescribed declined by 22%. The people most affected by the decrease appear to be those who reported benefit from opioid therapy.  

The amount of opioids that should be prescribed will remain open to debate. But millions of Americans have been -- and continue to be -- denied access to pain treatment, and there should be no debate about the fact that failure to treat severe pain is unacceptable.   

Everyone in the health care system and policymakers should be concerned about the NIH report on the prevalence of chronic pain. The dramatic increase in the number of people with chronic pain warrants our examination of all polices and resources to ensure that this population is receiving the care they need and deserve.  

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Lynn R. Webster, MD, is a vice president of scientific affairs for PRA Health Sciences and consults with the pharmaceutical industry. He is a former president of the American Academy of Pain Medicine and the author of “The Painful Truth.”

You can find Lynn on Twitter: @LynnRWebsterMD. 

The information in this column should not be considered as professional medical advice, diagnosis or treatment. It is for informational purposes only and represents the author’s opinions alone. It does not inherently express or reflect the views, opinions and/or positions of Pain News Network.

CDC: 50 Million Americans Have Chronic Pain

By Pat Anson, PNN Editor

The Centers for Disease Control and Prevention and other federal agencies have faced a fair amount of criticism over the years for adopting insensitive policies and guidelines that are often harmful to the pain community. But there are growing signs the CDC and other agencies are starting to listen to or at least better understand pain patients.

Today the CDC released a new report estimating that 50 million Americans – just over 20 percent of the adult population – have chronic pain. About 20 million of them have “high-impact chronic pain” -- pain severe enough that it frequently limits life or work activities. The estimates are based on the 2016 National Health Interview Survey of over 33,000 adults.

“Pain is a component of many chronic conditions, and chronic pain is emerging as a health concern on its own, with negative consequences to individual persons, their families, and society as a whole,” reported James Dahlhamer, PhD, of the CDC's Division of Health Interview Statistics.

Dahlhamer and his colleagues found that women, unemployed older adults, adults living in poverty, rural residents and people without public health insurance are significantly more likely to have chronic pain, while the risk of pain is lower for people with a bachelor’s degree.

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“Socioeconomic status appears to be a common factor in many of the subgroup differences in high-impact chronic pain prevalence,” they found. “Education, poverty, and health insurance coverage have been determined to be associated with both general health status and the presence of specific health conditions as well as with patients’ success in navigating the health care system. Identifying populations at risk is necessary to inform efforts for developing and targeting quality pain services.”

Different Estimates

Last week the National Institutes of Health (NIH) released its own research on high impact chronic pain (HICP), estimating that 11 million American adults have it -- about half the CDC’s estimate.

Both the NIH and CDC are part of the Department of Health and Human Services (HHS). It was not immediately clear why the two estimates are so far apart – or why two government agencies in the same department were studying the same thing at the same time.  

It’s certainly not the first time researchers have disagreed on the number of people in pain. In 2011, the Institute of Medicine released a landmark report claiming at least 100 million Americans have chronic pain, an estimate that one critic said was a “ridiculous number.” Other estimates range from 39 to 70 million.

“The multidimensional nature of chronic pain is not reflected in commonly used operational definitions… resulting in inordinately high prevalence estimates that limit our ability to effectively address chronic pain on a national level,” said Mark Pitcher, PhD, a visiting fellow at the National Center for Complementary and Integrative Health (NCCIH).

Like their counterparts at the CDC, NIH researchers found that socioeconomic factors play a significant role in high impact chronic pain. HICP sufferers not only have more severe pain, they are more likely to have mental and cognitive health issues, as well as substantially higher healthcare costs. About 83 percent of people with HICP are unable to work and one-third have difficulty with simple activities such as bathing and getting dressed.

“By differentiating those with HICP, a condition that is associated with higher levels of anxiety, depression, fatigue, and cognitive difficulty, we hope to improve clinical research and practice,” said co-author M. Catherine Bushnell, PhD, scientific director at NCCIH.

The concept of HICP was first proposed by the National Pain Strategy to better identify patients with pain severe enough to interfere with work and life activities. It also helps distinguish HICP from other types of chronic pain that are less impactful and more easily treated.

“It is crucial that we fully understand how people’s lives are affected by chronic pain. It will help improve care for individuals living with chronic pain and strategically guide our research programs that aim to reduce the burden of pain at the population level,” said Linda Porter, PhD, director of the Office of Pain Policy at the National Institute of Neurological Disorders and Stroke. 

The Food and Drug Administration has also recently taken steps to better understand the chronic pain population. In July, the FDA held a day-long public hearing and heard from dozens of pain patients and advocates. Some fought back tears as they testified about the lack of access to opioid medication and the deteriorating quality of pain care in the U.S.

Rats, Depression and Chronic Pain

By Pat Anson, Editor

An unusual study involving rats, depression and chronic pain is making headlines – the latest in a long line of flawed research studies being used to debunk the effectiveness of opioid pain medication.

“NIH study suggests opioid therapy not effective against chronic pain,” is the headline in UPI.

“Pain-induced changes in the brain explain the limited effectiveness of opioid therapy,” is how the Tech Explorist put it.

At issue is a small study by the National Institutes of Health (NIH) and McGill University in Montreal on pain-induced changes in 17 laboratory rats. That's right, 17 rats. The study findings, published in the journal Pain, concluded that chronic pain reduced the number of opioid receptors – the molecules that opioids bind to -- in the rats’ brains. In theory at least, that would make the rats less responsive to opioid pain medication.

Note that the research did not include any people, the rats were not given any opioids, and the effectiveness of opioids wasn't even measured in the rats. But that didn’t stop the NIH from drawing some sweeping conclusions.

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“These results provide insights into why we see limited effectiveness of opioid therapy in chronic pain and the mechanism of the depression that may accompany it,” said David Shurtleff, PhD, acting director at the National Center for Complementary and Integrative Health (NCCIH).

“These basic research findings support NIH’s efforts to better understand chronic pain and comorbid symptoms and to develop better ways to help chronic pain patients effectively manage their pain.”

McGill University was more cautious, saying further studies were needed in humans to confirm the study findings.

“Although the study… was conducted in rats, and the results of animal studies may not be directly applicable to people, the findings provide new insights into how the brain may respond to pain and opioids,” a McGill press release states. “These findings, if confirmed in people, will enhance the understanding of the impact of chronic pain on the brain, its relation to depression, and the effects of opioids.”

Researchers have many theories about the origins and treatment of chronic pain, but conducting tests on humans to prove them is problematic. Laboratory animals are often used as an imperfect substitute.

In the NIH/McGill study, 17 rats had brain surgeries to produce a nerve injury that causes chronic pain, while another group of rats had sham surgeries (a similar procedure that did not cause chronic pain). Three months later, PET scan imaging showed opioid receptors had decreased in multiple regions of the brain in the nerve-injured rats, but no changes occurred in the sham-surgery rats.

These results suggest that pain itself, not treatment or pre-existing trauma, altered the brain’s opioid system. Other tests showed a weaker link between chronic pain and depression in the nerve-injured rats.

How did researchers determine the rats were depressed? 

When given a choice, healthy rats will normally drink water sweetened with sugar rather than plain water. But animals with a decreased ability to experience pleasure, a recognized symptom of depression, may not. The rats in the study with chronic pain showed a decreased preference for sugar water over plain water, while rats in the sham group still showed a preference for sweetened water. This, the researchers believe, was enough evidence to conclude the nerve-injured rates were depressed.

“It’s well known that there’s a link between chronic pain and depression,” explained co-author M. Catherine Bushnell, PhD, scientific director of NCCIH’s Division of Intramural Research.  “The results of this study indicate that pain-induced changes in the brain’s opioid system may play a role in this association. Animals with the greatest decrease in opioid receptor availability showed the greatest increase in depression-like symptoms after experiencing chronic pain.”

While intriguing, the results of this rat study are far from definitive and do not prove that opioids are an ineffective treatment for chronic pain in people. What they do show is that we need more and better research about opioids and chronic pain, not more misleading headlines and statements from the NIH.

Trump Budget Cuts Would Further Limit Pain Research

By Pat Anson, Editor

The Trump administration has proposed another $1.2 billion in budget cuts for the National Institutes of Health (NIH), which experts say could hamper already anemic efforts at developing new treatments for chronic pain.  Most of the reductions at NIH would come from research grant funding.

Only about 1 percent of the NIH budget is designated for pain research, even though more Americans suffer from pain than heart disease, diabetes and cancer combined.

The proposed $1.2 billion reduction in this year’s NIH budget is in addition to the $5.8 billion cut the Trump Administration has already proposed for the agency in 2018.

The $7 billion in savings will be used to help pay for an enhanced border wall with Mexico and increased military spending.

The White House Office of Management and Budget says the NIH budget for 2018 “eliminates programs that are duplicative or have limited impact on public health” and would “help focus resources on the highest priority research and training activities.”

"I will be the first one down lobbying against this," said Ann Romney, who suffers from multiple sclerosis and is the wife of former GOP presidential nominee Mitt Romney.

"Nothing comes from nothing. If you don't have that funding, there will be nothing," she told Yahoo News. "There will be no new treatments, there will be no new drug therapies. Progress in medicine will come to a halt."

Pain Research Already Limited

The lack of spending on pain research -- by both the government and the healthcare industry – was a problem long before the Trump administration came out with its budget plans.

In 2012, researchers at Johns Hopkins University estimated that chronic pain costs the U.S. economy up to $635 billion a year in healthcare costs and lost productivity. Yet the NIH spent only $358 million on pain research that year, according to journalist Judy Foreman in her book, “A Nation in Pain.”

“It is a huge burden with very little actual research going into it. And still a lot of unmet medical need,” said Gabriel Baertschi, CEO of Grünenthal, a German pharmaceutical company. “The odds of succeeding in pain research are lower than in other areas. It’s much more complex than other diseases in a sense that if you hit one target you are not necessarily resolving pain. Pain is multi-dimensional. That explains why from a research point of view you don’t always succeed.”

Grünenthal is a research-oriented company that focuses on finding new treatments for conditions such as bladder pain and Complex Regional Pain Syndrome (CRPS). Recently the FDA designated an experimental drug being developed by Grünenthal as a potential breakthrough therapy for CRPS. The company is now in advanced stages of clinical trials.

Because it’s smaller and privately owned, Baertschi says Grünenthal can afford to explore new treatments for rare diseases that “Big Pharma” companies are not interested in developing.

“Most of the companies that were active in pain have closed their pain research centers,” he told PNN in an interview last month. “I think a lot of companies are pulling out because the cost of developing pain drugs has been immense. If you look at the latest generation of pain drugs, it has cost billions of dollars.

“That has scared off companies and I think companies are more focused on areas where the returns are better from a pricing point of view. Because quite frankly, if you look at oncology you can get (drug) prices that are far better than for pain.”

Insurers Refuse to Pay for New Treatments

Another problem is insurance coverage. A few years ago the U.S. Food and Drug Administration pressured drug makers to develop abuse deterrent technology for opioids to reduce the risk of abuse and addiction. Some companies spent hundreds of millions of dollars developing abuse deterrent opioids that insurers now refuse to pay for because they are more expensive.

“Payers are a huge barrier to innovative therapies because they block coverage. Without insurance coverage there is little incentive to invest,” said Lynn Webster, MD, a leading expert and researcher in pain management, who is vice president of Scientific Affairs at PRA Health Sciences. 

“In the past 30 years there haven't been more than 3 new chemical entities approved by the FDA. One reason is that we don't understand enough about the different mechanisms generating pain,” Webster explained. “I see our current approach is similar to how cancer research was conducted 60 years ago.  Back then most cancers were treated with the same monotherapies.  Once research delved into the multi-mechanistic contributions to cancer, therapeutic advances were possible. We need to do the same for pain. And insurance has to pay for the innovations.”

“Pain is unfortunately penalized by society. People feel there is enough treatment available,” said Grünenthal’s Baertschi. “There are a lot of very good pain therapies out there. But there are quite a few areas, especially niche areas and specific pain types, that are not being treated adequately and that’s where we focus our research.”

One analyst said it is unlikely Congress will go along with the proposed cuts in the NIH budget because it funds politically popular programs.

"At worst, we believe NIH (funding) will remain flat in a continuing resolution if there is a government spending standoff," wrote Cowen analyst Doug Schenkel in a note to investors. "Although NIH funding hasn't kept up with inflation, the only time there were cuts to the agency in the past decade was when Congress' hand was forced by sequestration."

A Coalition to Save NIH Funding has also been formed to lobby against the budget cuts.

"We were dismayed to learn that the NIH is vulnerable to deep funding cuts," said Carrie Jones of JPA Health Communications, which is managing the coalition. "Each day America benefits from the innovation and scientific discoveries made at the NIH. We won't sit idly by and watch critical research be stifled."