title: Costs and work limitation of patients with ankylosing spondylitis in China.
abstract: OBJECTIVE
  To access the annual direct, indirect costs and work limitation of AS patients in Chinese population and explore the determinants of cost.
  
  
  METHODS
  A retrospective, cross-sectional study was performed in 257 patients with AS in China. The participants completed questionnaires about disease characteristics, quality of life and direct and indirect costs. Only the patients with paid-work completed the Work Limitation Questionnaire (WLQ), a 25-item questionnaire that accesses the impact of chronic health conditions on job performance and productivity. Functional impairment and disease activity were assessed using the Bath Ankylosing Spondylitis Functional Index (BASFI) and the Bath Akylosing Spondylitis Disease Activity Index (BASDAI). Quality of life was measured by the Short Form-36.
  
  
  RESULTS
  Of the 257 patients who completed the questionnaires, the mean age was 28.5 (SD=0.5) with mean disease duration of 6.52 years (SD=0.44). The mean BASDAI and BASFI score was 3.28 and 1.3, respectively. Among the 257 patients, 21.8% are students, 64.2% have a paid job and 10.5% without a job because of AS. 165 participants finished the WLQ with a mean WLQ index of 0.19 which corresponds to a 17% decrease in productivity. The annual estimated costs of each patient was $2714.18 while the indirect cost accounted for 64.7%. The annual direct cost significantly correlated with disease activity.
  
  
  CONCLUSIONS
  Our research is the first to provide information about the burden of AS and the work status of AS patients in mainland China, which may help to establish the treatment strategy and a policy of support.
authors.affiliation: Department of Rheumatology, Third Affiliated Hospital of Sun Yat-sen University, Guangzhou, China. tld_717@163.com.
authors.forename: Liudan
authors.initials: L
authors.lastname: Tu
authors.forename: Jayanti Chamling
authors.initials: JC
authors.lastname: Rai
authors.forename: Shuangyan
authors.initials: S
authors.lastname: Cao
authors.forename: Zhiming
authors.initials: Z
authors.lastname: Lin
authors.forename: Zaiying
authors.initials: Z
authors.lastname: Hu
authors.forename: Jieruo
authors.initials: J
authors.lastname: Gu
mesh_terms: D000041:Absenteeism; D000293:Adolescent; D000328:Adult; D002681:China; D017281:Cost of Illness; D003430:Cross-Sectional Studies; D004526:Efficiency; D005260:Female; D017048:Health Care Costs; D006801:Humans; D007182:Income; D008297:Male; D008875:Middle Aged; D011788:Quality of Life; D012189:Retrospective Studies; D018582:Sick Leave / Q000191:economics*; D013167:Spondylitis, Ankylosing / Q000175:diagnosis* / Q000191:economics* / Q000628:therapy; D011795:Surveys and Questionnaires; D013997:Time Factors; D014938:Work Capacity Evaluation; D055815:Young Adult