title: The societal burden of chronic pain in Japan: an internet survey.
abstract: OBJECTIVE
  Chronic pain affects between 10-20 % of the population of Japan and several specific types of chronic pain have been found to be associated with worse health outcomes. The aim of the current study was to investigate the economic burden of chronic pain as well as the health status among Japanese patients.
  
  
  METHODS
  Data from the Japan National Health and Wellness Survey (NHWS), a cross-sectional health survey of adults, were used (N = 30,000). Respondents with chronic pain (N = 785) were compared with respondents without chronic pain (N = 29,215) with respect to health status (using the SF-12v2), work productivity and activity impairment (WPAI questionnaire), and healthcare resource use using regression modeling, controlling for demographic and health history covariates. Indirect costs were calculated using wage rates and the human capital method.
  
  
  RESULTS
  Back pain (72.10 %) and shoulder pain/stiffness (54.90 %) were the most prevalent pain types. Adjusting for demographic and health history differences, respondents with chronic pain reported lower health status [mental component summary (MCS): 44.26 vs. 51.14; physical component summary (PCS): 44.23 vs. 47.48; both p < 0.05], greater absenteeism (4.74 vs. 2.74 %), presenteeism (30.19 vs. 15.19 %), overall work impairment (31.70 vs. 16.82 %), indirect costs (¥ 1488,385 vs. ¥ 804,634), activity impairment (33.45 vs. 17.25 %), physician visits (9.31 vs. 4.08), emergency room (ER) visits (0.19 vs. 0.08), and hospitalizations (0.71 vs. 0.34) (all p < 0.05). Nearly 60 % of respondents with chronic pain were untreated. The mean level of pain severity in the last week was 5.26 (using a 0-11 scale); being female, being elderly, having low income, and having multiple pain types were significantly associated with greater pain severity (all p < 0.05). Regular exercise was associated with lower pain severity (p < 0.05).
  
  
  CONCLUSIONS
  The results suggest that chronic pain has a significant association in an individual's health status, work productivity, daily activity impairment, healthcare resource use, and economic burden in Japan. Along with low treatment rates, a multidisciplinary approach may lead to an improved quality of life and reduce the economic burden among patients with chronic pain in Japan.
authors.affiliation: Department of Health Economics and Industrial Policy, Osaka University Graduate School of Medicine, Osaka, Japan.
authors.forename: Tomoyuki
authors.initials: T
authors.lastname: Takura
authors.forename: Takahiro
authors.initials: T
authors.lastname: Ushida
authors.forename: Tsukasa
authors.initials: T
authors.lastname: Kanchiku
authors.forename: Nozomi
authors.initials: N
authors.lastname: Ebata
authors.forename: Koichi
authors.initials: K
authors.lastname: Fujii
authors.forename: Marco daCosta
authors.initials: Md
authors.lastname: DiBonaventura
authors.forename: Toshihiko
authors.initials: T
authors.lastname: Taguchi
mesh_terms: D000203:Activities of Daily Living / Q000523:psychology*; D000328:Adult; D059350:Chronic Pain / Q000191:economics* / Q000453:epidemiology / Q000523:psychology; D017281:Cost of Illness; D003430:Cross-Sectional Studies; D005260:Female; D006304:Health Status; D006306:Health Surveys / Q000379:methods*; D006801:Humans; D020407:Internet; D007564:Japan / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D011788:Quality of Life