Chronic pain. Epidemiological studies in a general population

Abstract: The aim was to study the epidemiology of chronic pain (> 3 months duration) and factors associated to pain prevalence, prognosis, health care and medication in a general population. A cross-sectional mailed survey to a random population sample (n = 1806) was followed by a clinical examination and a prospective study of three selected groups. Pain related diagnoses from primary health care was monitored and compared with pain prevalence. The most important findings were: - a high total prevalence of chronic pain, 55.2%, without gender difference but varying by age and socioeconomic level. About one fourth (12.8%) reported high pain intensity and functional impairments. Women experienced pain at more locations and with higher intensity. - in a multivariate analysis increasing age, female gender, low education, high work strain, depression and insomnia were associated with chronic pain. - widespread pain showed a worse 2- year prognosis compared with neck shoulder pain. - musculoskeletal location of pain dominated, myalgia and myofascial pain being the most common symptom descriptions. - co-morbidity with chronic pain was common. More hypertensives and an increased level of serum uric acid associated to widepread pain indicated possible metabolic connections to pain. - smoking (current and previous) was associated with low-back and widespread pain. - chronic pain had a substantial influence of primary health care-seeking and medication; high pain intensity being the most important predictor of care and medication. - pain related diagnoses in primary health care increased between 1987 and 1996. Chronic pain, mainly with musculoskeletal location, is a community health problem. A multi-factorial approach in prevention and treatment on the basis of present knowledge is necessary.