The epidemiology of chronic pain

Epidemiological studies have demonstrated that, within the past month, around half us will have experienced an episode of pain which has lasted at least 1 day, with the most common sites reported, in a United Kingdom population study, being the low back (30%), hip (25%), neck and shoulder (25%) and knee (24%).9 Using a more stringent definition (suffered pain for 6 months, experienced pain in the last month and several times during the last week), a pan-European study reported a prevalence of 19%.

Prevalence of chronic pain increases through adult life, reaching a peak around the seventh decade (eg, Ref. 5). Pain at some regional sites, particularly in the lower limb, increase in prevalence across the age range (eg, Ref. 12), whereas some such as low back pain decrease at older ages.3 Such a decrease has been hypothesised to be related to changes in pain perception, expectation of pain at older ages and comorbidities. Chronic pain may be related to premature mortality; a review of studies showed a relationship with cancer and cardiovascular death 11 which may partly be related to lifestyle factors such as low levels of physical activity and poor quality diet