title: An examination of work instability, functional impairment, and disease activity in employed patients with rheumatoid arthritis.
abstract: OBJECTIVE
  To evaluate the relationship between the Disease Activity Score 28-joint count (DAS28), Health Assessment Questionnaire (HAQ), and Rheumatoid Arthritis-Work Instability Scale (RAWIS); and to define thresholds for clinical assessments associated with moderate to high RA-WIS.
  
  
  METHODS
  Employed patients with RA were evaluated using DAS28, HAQ, and RA-WIS during routine clinics. Relationships between these assessments were evaluated by simple correlation. Multiple linear regression modeling was performed using RA-WIS as an outcome variable and HAQ, DAS28, age, sex, occupation, and disease duration as input variables. Receiver-operating characteristic curves were then formulated to determine optimal DAS28, and HAQ cutoff points for RA-WIS >or= 10, along with the odds ratio (OR).
  
  
  RESULTS
  Ninety patients with RA completed the RA-WIS, which was moderately correlated with DAS28 (r =0.53) and HAQ (r = 0.66). Fifty-four percent of RA-WIS was explained by DAS28 (p = 0.002), HAQ (p = 0.001), and sex (p = 0.04). A DAS28 of 3.81 and HAQ of 0.55 were clinically important thresholds. High DAS28 and HAQ were associated with high RA-WIS (OR(DAS) 14.17, OR(HAQ) 25.13, OR(DAS+HAQ) 29.9).
  
  
  CONCLUSIONS
  Functional impairment and disease activity significantly and independently contributed to patient-perceived work instability risk.
authors.affiliation: Guy's and St. Thomas' NHS Foundation Trust, London, UK.
authors.forename: Alyssa
authors.initials: A
authors.lastname: Macedo
authors.forename: Stephen
authors.initials: S
authors.lastname: Oakley
authors.forename: Nicola
authors.initials: N
authors.lastname: Gullick
authors.forename: Bruce
authors.initials: B
authors.lastname: Kirkham
mesh_terms: D000203:Activities of Daily Living / Q000523:psychology*; D000328:Adult; D017677:Age Distribution; D000368:Aged; D001172:Arthritis, Rheumatoid / Q000453:epidemiology*; D003430:Cross-Sectional Studies; D004185:Disability Evaluation; D004651:Employment / Q000706:statistics & numerical data; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009790:Occupations / Q000706:statistics & numerical data; D012044:Regression Analysis; D012307:Risk Factors; D012720:Severity of Illness Index; D017678:Sex Distribution; D018582:Sick Leave / Q000706:statistics & numerical data*; D011795:Surveys and Questionnaires; D014938:Work Capacity Evaluation; D055815:Young Adult