title: Health Assessment Questionnaire disability progression in early rheumatoid arthritis: systematic review and analysis of two inception cohorts.
abstract: OBJECTIVE
  The Health Assessment Questionnaire is widely used for patients with inflammatory polyarthritis (IP) and its subset, rheumatoid arthritis (RA). In this study, we evaluated the progression of HAQ scores in RA (i) by systematically reviewing the published literature on the methods used to assess changes in functional disability over time and (ii) to study in detail HAQ progression in two large prospective observational studies from the UK.
  
  
  METHODS
  Data from two large inception cohorts, ERAS and NOAR, were studied to determine trajectories of HAQ progression over time by applying latent class growth models (LCGMs) to each dataset separately. Age, sex, baseline DAS28, symptom duration, rheumatoid factor, fulfilment of the 1987 ACR criteria and socio-economic status (SES) were included as potential predictors of HAQ trajectory subgroup membership.
  
  
  RESULTS
  The literature search identified 49 studies showing that HAQ progression has mainly been based on average changes in the total study population. In the HAQ progression study, a LCGM with four HAQ trajectory subgroups was selected as providing the best fit in both cohorts. In both the cohorts, older age, female sex, longer symptom duration, fulfilment of the 1987 ACR criteria, higher DAS28 and lower SES were associated with increased likelihood of membership of subgroups with worse HAQ progression.
  
  
  CONCLUSIONS
  Four distinct HAQ trajectory subgroups were derived from the ERAS and NOAR cohorts. The fact that the subgroups identified were nearly identical supports their validity. Identifying distinct groups of patients who are at risk of poor functional outcome may help to target therapy to those who are most likely to benefit.
authors.affiliation: Psychology Department, Institute of Psychiatry, King׳s College London, London, UK.
authors.forename: Sam
authors.initials: S
authors.lastname: Norton
authors.affiliation: Centre for Biostatistics, Institute of Population Health, The University of Manchester, Manchester, UK.
authors.forename: Bo
authors.initials: B
authors.lastname: Fu
authors.affiliation: Department of Rheumatology, Kings College Hospital, London, UK.
authors.forename: David L
authors.initials: DL
authors.lastname: Scott
authors.affiliation: Department of Rheumatology, Medical Specialities Out-Patients, Rehabilitation Block, Royal Derby Hospital, Derby, UK.
authors.forename: Chris
authors.initials: C
authors.lastname: Deighton
authors.affiliation: Arthritis Research UK Centre for Epidemiology, Centre for Musculoskeletal Research, Institute of Inflammation and Repair, The University of Manchester, Manchester Academic Health Science Centre, Stopford Building, Oxford Rd, Manchester M13 9PT, UK; NIHR Manchester Musculoskeletal Biomedical Research Unit, Central Manchester University Hospitals NHS Foundation Trust and University of Manchester Partnership, Manchester, UK.
authors.forename: Deborah P M
authors.initials: DP
authors.lastname: Symmons
authors.affiliation: School of Health and Related Research, University of Sheffield, UK.
authors.forename: Allan J
authors.initials: AJ
authors.lastname: Wailoo
authors.affiliation: School of Health and Related Research, University of Sheffield, UK.
authors.forename: Jonathan
authors.initials: J
authors.lastname: Tosh
authors.affiliation: Arthritis Research UK Centre for Epidemiology, Centre for Musculoskeletal Research, Institute of Inflammation and Repair, The University of Manchester, Manchester Academic Health Science Centre, Stopford Building, Oxford Rd, Manchester M13 9PT, UK.
authors.forename: Mark
authors.initials: M
authors.lastname: Lunt
authors.affiliation: Arthritis Research UK Centre for Epidemiology, Centre for Musculoskeletal Research, Institute of Inflammation and Repair, The University of Manchester, Manchester Academic Health Science Centre, Stopford Building, Oxford Rd, Manchester M13 9PT, UK.
authors.forename: Rebecca
authors.initials: R
authors.lastname: Davies
authors.affiliation: Early Rheumatoid Arthritis Study, City Hospital, St Albans, UK.
authors.forename: Adam
authors.initials: A
authors.lastname: Young
authors.affiliation: Arthritis Research UK Centre for Epidemiology, Centre for Musculoskeletal Research, Institute of Inflammation and Repair, The University of Manchester, Manchester Academic Health Science Centre, Stopford Building, Oxford Rd, Manchester M13 9PT, UK. Electronic address: Suzanne.Verstappen@manchester.ac.uk.
authors.forename: Suzanne M M
authors.initials: SM
authors.lastname: Verstappen
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D018501:Antirheumatic Agents / Q000627:therapeutic use; D001172:Arthritis, Rheumatoid / Q000175:diagnosis* / Q000188:drug therapy; D001688:Biological Products / Q000627:therapeutic use; D015331:Cohort Studies; D004185:Disability Evaluation; D018450:Disease Progression; D005260:Female; D006801:Humans; D008297:Male; D008727:Methotrexate / Q000627:therapeutic use; D008875:Middle Aged; D063868:Patient Outcome Assessment; D011446:Prospective Studies; D011795:Surveys and Questionnaires; D016896:Treatment Outcome; D006113:United Kingdom; D055815:Young Adult
chemical_list: D018501:Antirheumatic Agents; D001688:Biological Products; D008727:Methotrexate
keywords: Health Assessment Questionnaire; Inflammatory polyarthritis; Latent class growth model; Predictors; Rheumatoid arthritis; Systematic review