Pain

“Pain is a more terrible lord of mankind than even death itself.”1

Thus wrote Albert Schweitzer, physician, humanitarian and Nobel Prize Laureate in 1931. His words elegantly describe the nature of pain and the obligation of health care providers to relieve it.

Pain, as defined by the International Association for the Study of Pain, is an unpleasant sensory and emotional experience that is associated with or described in terms of either potential or actual tissue damage.2 Acute and chronic pain are completely different entities. Pain evaluation is now the so-called fifth vital sign.3

Current epidemiology

Neuropathic pain

General population studies, using validated screening instruments, have found that 7–8% of adults currently have chronic pain with neuropathic characteristics. The incidence (new cases) of neuropathic pain was found to be around 8 cases per 1,000 person-years.4

  • 37% of people attending primary care clinics with chronic low back have predominantly neuropathic pain.
  • 26% of people with diabetes were found to have peripheral neuropathic pain. Worldwide, this figure translates to some 47 million individuals, which will increase as the prevalence of diabetes grows (from 2.8% in 2000 to an estimated 4.4% in 2030).
  • Of the 33 million people infected with HIV across the world, around 35% have neuropathic pain, which does not respond well to standard treatments.
  • A study found that 40% of people have persistent pain after surgery, of which a quarter of cases have neuropathic characteristics. Neuropathic postsurgical pain is more likely to be severe and persistent than non-neuropathic postsurgical pain.
  • Approximately 20% (18.7–21.4%) of people with cancer have cancer-related neuropathic pain, as a result of either the disease or its treatment.
  • The lifetime incidence of herpes zoster (shingles) is around 25%. Studies in the United States and the Netherlands found that 2.6% and 10%, respectively, will develop chronic postherpetic neuralgia.

Chronic pain

The overall point prevalence of chronic pain was 13%, and the mean intensity of pain on Numeric rating scale (NRS) scale was 6.93. Sixty three percentages of patients with chronic pain had severe pain. Pain in knees (32%), legs (28%), and joints (22%) was most prevalent. Patients with chronic pain were no longer able to exercise, sleep, maintain relationships with friends and family, and maintain an independent lifestyle. About 32% of patients lost ≥4 hours of work in the past 3 months.5

References

  1. Bonica J. J. History of pain concepts and therapies. 1990:2–13. In: Bonica JJ, et al. Editors. The Management of Pain. 2nd Edition. Malvern, PA: Lea & Febiger.
  2. Siddall P. J., Hudspith M. J., Munglani R. Sensory systems and pain. 2000:213–232. In: Hemmings HC Jr, Hopkins PM, editors. Foundations of Anesthesia: Basic and Clinical Science. Philadelphia: Mosby.
  3. Thomas MA. Pain management - the challenge. Ochsner J. 2003 Spring;5(2):15-21.
  4. International Association for the Study of Pain. Epidemiology of Neuropathic Pain: How Common is Neuropathic Pain, and What Is Its Impact? 2014;1-2.
  5. Dureja GP, Jain PN, Shetty N, Mandal SP, Prabhoo R, Joshi M, Goswami S, Natarajan KB, Iyer R, Tanna DD, Ghosh P, Saxena A, Kadhe G, Phansalkar AA. Prevalence of chronic pain, impact on daily life, and treatment practices in India. Pain Pract. 2014 Feb;14(2):E51-62. doi: 10.1111/papr.12132.