Friday, June 25, 2010

Chronic Pain Surveys Portray a World of Hurt

Chronic pain has often been depicted as a worldwide problem of epidemic proportions. Until recently, however, there has been no comparison and consolidation of the diverse surveys examining this issue, and the conclusion is that chronic pain may be a problem of even more catastrophic significance than many imagine.

An investigator at the American University of Beirut, Lebanon, conducted what is probably the first-ever extensive search of the peer-reviewed literature for epidemiological studies reporting the prevalence of chronic pain and associated factors in adults [Abu-Saad Huijer 2010]. Fourteen studies were included in this analysis, spanning 1997 to 2008, and here are some of the noteworthy findings:
  • Overall, studies conducted in different parts of the world reported prevalence rates of chronic pain ranging from 12% to 80%. The extreme high end included special populations; eg, veterans with post-traumatic stress disorder in one study (80%) and persons ≥age 65 experiencing pain lasting one day or longer but excluding acute pain (72%).

  • The largest international studies, covering 15 and 17 countries each, found chronic pain prevalence rates of 12% to 41%. Generally, the prevalence was greater in developing countries and lower but still problematically high in more developed countries. In all countries chronic pain was significantly associated with depression and anxiety disorders but, interestingly, rates of arthritis/joint pain were higher in developed countries.

  • Almost all studies show that chronic pain is more prevalent among females than males and among persons aged 40 to 60 years. As might be expected, prevalence rates typically increase with age of the population studied; for example, in one study of persons aged ≥65 chronic pain was reported by 41% in contrast to another study in which 16% of young Gulf war veterans in the United States reported chronic pain.

  • Also significantly associated with chronic pain in most studies were being unemployed, having fewer years of education, and being widowed or divorced.

  • The most frequently used non-drug therapies for chronic pain included massage, physical therapy, and acupuncture. Many patients also reported using rest and hot or cold packs.

  • In a large pan-European study, encompassing 15 countries (46,400 participants), more than a third (36%) of chronic pain sufferers were taking one or more non-prescription medications. Of those using prescription medications, 44% were taking NSAIDs (these being Rx-only in many countries), 23% weak opioids, and 5% strong opioids. Yet, nearly 40% of participants were dissatisfied with the treatment they were receiving and 38% were not satisfied with the physician treating their pain.

  • Of great importance, in the pan-European study 40% of participants with chronic pain felt that it prevented them from functioning and they felt helpless; 16% wished for death because of their chronic pain! Furthermore, 30% thought that their loved ones did not believe the intensity of their pain, and 1 in 4 felt that the people around them, including their healthcare providers, were insensitive to their pain-related problems.
FURTHER OBSERVATIONS: There are some limitations to note. Most studies generally define chronic pain as being continuously experienced for at least 3 months in the last 6 months prior to the study, or pain lasting 6 months or longer; yet, there does not appear to be a consistent way of assessing and reporting on the duration of pain across studies. And, although musculoskeletal disease always tops the list of pain-related conditions, the studies often encompass diverse types of chronic pain and there is no international standard for reporting prevalence rates by category.

Besides the published studies noted above, a number of organizations have emphasized that chronic pain is an underestimated and under-appreciated healthcare problem of major proportions. For example, the European Federation of the International Association for the Study of Pain Chapters (EFIC) estimates that 1 in 5 persons worldwide suffers from moderate to severe chronic pain, and a third of them are unable to maintain an independent lifestyle due to their disorders. Additionally, up to two-thirds of persons with chronic pain cannot perform normal daily activities and, as a result, a quarter report broken or strained relationships with family or friends. Hence, the economic costs of chronic pain to society are calamitous in some countries [see EFIC data here]. Similarly, the American Pain Foundation (APF) estimates that 26% of Americans age ≥20 (76.5 million persons) have chronic pain to some extent; other trends in the United States — relating to gender, age, income level — also are comparable to those reported by international surveys noted above [see APF data here].

Taken together, the various data overwhelmingly suggest that persons with chronic pain make up a substantially large proportion of the worldwide population. Add to this the family and friends impacted by loved ones who cannot function normally due to chronic pain and the total number of affected citizens in each country becomes enormous. The recognition and effective treatment of chronic pain is not only a public health crisis but may (probably should) become a major political agenda item if those citizens ever band together in a collective cry for action. So far, throughout the world, it seems that the cries have been muffled and a “silence of the lambs” has prevailed; but this could change. In the United States at least two organizations — the American Pain Foundation [here] and the American Chronic Pain Association [here] — serve the special needs and interests of persons with chronic pain and their families, and seek to influence beneficial legislation and political action.

REFERENCE: Abu-Saad Huijer H. Chronic pain: A review. Leb Med J. 2010;58(1):21-27 [article PDF here].