title: Evaluation of Ankylosing Spondylitis Quality of Life questionnaire: responsiveness of a new patient-reported outcome measure.
abstract: OBJECTIVE
  To determine the responsiveness and minimal important change (MIC) of Evaluation of Ankylosing Spondylitis Quality of Life (EASi-QoL), a reliable and valid patient-reported measure of AS-specific quality of life with four domains: physical function (PF), disease activity (DA), emotional well-being (EWB) and social participation (SP).
  
  
  METHODS
  A total of 1000 UK AS patients received a postal questionnaire including EASi-QoL. Comparative responsiveness of EASi-QoL was assessed against measures reflecting similar health domains in patients self-reporting an improvement in their AS-specific health at 6 months on a health transition question. Effect size (ES) statistics were calculated for all measures and MIC was determined for EASi-QoL. Comparative responsiveness was determined in a randomized trial of AS patients receiving etanercept (ETN) 50 mg weekly or SSZ 3 g daily.
  
  
  RESULTS
  Of 470 patients, 80 responding at 6 months reported health improvement. Responsiveness (ES) for EASi-QoL domains was superior or similar to comparator measures: DA 0.72 vs BASDAI 0.58; SP 0.52 vs SF-36 social functioning 0.29; PF 0.32 vs BASFI 0.28 and SF-36 PF 0.24; EWB 0.40 vs HADS-anxiety 0.13, HADS-depression 0.21 and SF-36 mental health 0.35. ES for the ASQoL was 0.40. Superior ES was seen in those improving somewhat. In the randomized trial, all EASi-QoL domains had superior responsiveness to comparator measures following ETN treatment. Following SSZ treatment, all EASi-QoL domains were highly responsive, but BASDAI and BASFI was more responsive than EASi-QoL(DA) and (PF), respectively.
  
  
  CONCLUSIONS
  In patients reporting improvement during routine clinical practice or following treatment with ETN or SSZ, EASi-QoL domains have superior or comparable responsiveness than comparable measures.
authors.affiliation: Arthritis Research UK Primary Care Centre, Keele University, Staffordshire ST5 5BG, UK. j.packham@cphc.keele.ac.uk
authors.forename: Jon C
authors.initials: JC
authors.lastname: Packham
authors.forename: Kelvin P
authors.initials: KP
authors.lastname: Jordan
authors.forename: Kirstie L
authors.initials: KL
authors.lastname: Haywood
authors.forename: Andrew M
authors.initials: AM
authors.lastname: Garratt
authors.forename: Emma L
authors.initials: EL
authors.lastname: Healey
mesh_terms: D000328:Adult; D000368:Aged; D018501:Antirheumatic Agents / Q000627:therapeutic use; D004311:Double-Blind Method; D000068800:Etanercept; D005260:Female; D006801:Humans; D007074:Immunoglobulin G / Q000627:therapeutic use; D007398:Interpersonal Relations; D008297:Male; D008603:Mental Health; D008875:Middle Aged; D017060:Patient Satisfaction; D011788:Quality of Life; D018124:Receptors, Tumor Necrosis Factor / Q000627:therapeutic use; D012720:Severity of Illness Index; D013167:Spondylitis, Ankylosing / Q000188:drug therapy / Q000503:physiopathology / Q000523:psychology / Q000534:rehabilitation*; D011795:Surveys and Questionnaires; D016896:Treatment Outcome
chemical_list: D018501:Antirheumatic Agents; D007074:Immunoglobulin G; D018124:Receptors, Tumor Necrosis Factor; D000068800:Etanercept