title: Comorbidities, intensity, frequency and duration of pain, daily functioning and health care seeking in local, regional, and widespread pain - a descriptive population-based survey (SwePain).
abstract: BACKGROUND
  The clinical knowledge of factors related to the spread of pain on the body has increased and understanding these factors is essential for effective pain treatment. This population-based study examines local (LP), regional (RP), and widespread pain (WSP) on the body regarding comorbidities, pain aspects, and impact of pain and elucidates how the spread of pain varies over time.
  
  
  METHODS
  A postal questionnaire that addressed pain aspects (intensity, frequency, duration and anatomical spreading on a body manikin), comorbidities and implications of pain (i.e., work situation, physical activity, consumption of health care and experience of hospitality and treatment of health care) was sent to 9000 adults living in southeastern Sweden. Of these, 4774 (53 %) completed and returned the questionnaire. After 9 weeks, a follow-up questionnaire was sent to the 2983 participants who reported pain in the first questionnaire (i.e. 62 % of 4774 subjects). Of these, 1940 completed and returned the questionnaire (i.e. 65 % of 2983 subjects). The follow-up questionnaire included the same items as the first questionnaire.
  
  
  RESULTS
  This study found differences in intensity, frequency and duration of pain, comorbidities, aspects of daily functioning and health care seeking in three pain categories based on spreading of pain: LP, RP and WSP. Compared to the participants with RP and LP, the participants with WSP had lower education and worse overall health, including more frequent heart disease and hypertension. In addition, participants with WSP had more intense, frequent, and long-standing pain, required more medical consultations, and experienced more impact on work. The participants with RP constituted an intermediate group regarding frequency and intensity of pain, and impact on work. The participants with LP were the least affected group regarding these factors. A substantial transition to RP had occurred by the 9-week follow-up.
  
  
  CONCLUSIONS
  This study shows an association between increased spread of pain and prevalence of heart disease, hypertension, more severe pain characteristics (i.e., intensity, frequency and duration), problems with common daily activities and increased health care seeking. The WSP group was the most affected group and the LP group was the least affected group. Regarding these factors, RP was an obvious intermediate group. The transitions between the pain categories warrant research that broadly investigates factors that increase and decrease pain.
authors.affiliation: Occupational and Environmental Medicine, University of Gothenburg, Gothenburg, Sweden. Anna.Ekman@amm.gu.se.|Division of Community Medicine, Department of Medical and Health Sciences, Faculty of Health Sciences, Linköping University, Pain and Rehabilitation Center, Anaesthetics, Operations and Specialty Surgery Center, County Council of Östergötland, Linköping, Sweden. Anna.Ekman@amm.gu.se.
authors.forename: Anna
authors.initials: A
authors.lastname: Grimby-Ekman
authors.affiliation: Division of Community Medicine, Department of Medical and Health Sciences, Faculty of Health Sciences, Linköping University, Pain and Rehabilitation Center, Anaesthetics, Operations and Specialty Surgery Center, County Council of Östergötland, Linköping, Sweden. Bjorn.Gerdle@liu.se.
authors.forename: Björn
authors.initials: B
authors.lastname: Gerdle
authors.affiliation: Division of Occupational and Environmental Medicine, AMM, Lund University, Lund, Sweden. Jonas.Bjork@med.lu.se.
authors.forename: Jonas
authors.initials: J
authors.lastname: Björk
authors.affiliation: Division of Community Medicine, Department of Medical and Health Sciences, Faculty of Health Sciences, Linköping University, Pain and Rehabilitation Center, Anaesthetics, Operations and Specialty Surgery Center, County Council of Östergötland, Linköping, Sweden. Britt.Larsson@liu.se.
authors.forename: Britt
authors.initials: B
authors.lastname: Larsson
mesh_terms: D000203:Activities of Daily Living; D000328:Adult; D015897:Comorbidity; D017281:Cost of Illness; D018450:Disease Progression; D004522:Educational Status; D005260:Female; D006304:Health Status; D006306:Health Surveys; D006801:Humans; D008297:Male; D008875:Middle Aged; D010146:Pain / Q000175:diagnosis / Q000453:epidemiology* / Q000503:physiopathology / Q000517:prevention & control / Q000523:psychology; D010147:Pain Measurement; D010342:Patient Acceptance of Health Care; D011237:Predictive Value of Tests; D015995:Prevalence; D011379:Prognosis; D012307:Risk Factors; D012720:Severity of Illness Index; D011795:Surveys and Questionnaires; D013548:Sweden / Q000453:epidemiology; D013997:Time Factors