title: The Effect of Disease Severity and Comorbidity on Length of Stay for Orthopedic Surgery in Rheumatoid Arthritis: Results from 2 UK Inception Cohorts, 1986-2012.
abstract: OBJECTIVE
  To examine factors predicting length of stay (LoS) for orthopedic intervention in rheumatoid arthritis (RA).
  
  
  METHODS
  LoS for orthopedic intervention was examined in 2 consecutive, multicenter inception cohorts: the Early RA Study (n = 1465, 9 centers) and the Early RA Network (n = 1236, 23 centers). Date, type of orthopedic procedure, and LoS were recorded and validated against national data, the UK National Joint Registry, and the UK Hospital Episode Statistics database. Clinical, laboratory, and radiographic measures and comorbidity recorded at baseline and annually were examined for their predictive power on LoS using regression analysis.
  
  
  RESULTS
  A total of 770 of 2701 patients (28.5%) had 1602 orthopedic interventions: 40% major (mainly total hip/knee replacements), 24% intermediate (mainly hand/wrist and ankle/foot surgery), and 16% minor (mainly soft tissue surgery). Median (interquartile range) LoS was 8 (5-13), 3 (1-5), and 1 (0-2) days for major, intermediate, and minor interventions, respectively. Older age predicted longer LoS (p < 0.001) whereas a more recent operation year predicted shorter LoS (p < 0.001). Markers of active disease, namely low hemoglobin, high Health Assessment Questionnaire, and high Disease Activity Scores in the first year all predicted longer LoS for all types of surgery (p = 0.001, p < 0.001, p = 0.05, respectively). Presence of 1 or more major comorbidities predicted longer LoS (p < 0.001).
  
  
  CONCLUSIONS
  Comorbidity and standard clinical and laboratory markers of disease activity affect the LoS for orthopedic surgery in RA, which has important clinical and economic implications, providing a target for improving patient outcomes.
authors.affiliation: From the Department of Applied Health Research, and the Institute of Musculoskeletal Science, University College London; Department of Rheumatology, St. Georges Healthcare National Health Service (NHS) Trust, London; Early Rheumatoid Arthritis Study (ERAS)/Early Rheumatoid Arthritis Network (ERAN), Department of Rheumatology, St. Albans City Hospital, St. Albans; School of Life and Medical Sciences, University of Hertfordshire, Hatfield; Department of Rheumatology, New Cross Hospital, Wolverhampton; Department of Rheumatology, Medway Maritime Hospital, Gillingham; Arthritis UK Pain Centre, University of Nottingham, UK.E. Nikiphorou, MBBS/BSc, MRCP, MD(Res), PGCME, FHEA, Department of Applied Health Research, University College London, and ERAS/ERAN, Department of Rheumatology, St. Albans City Hospital, and School of Life and Medical Sciences, University of Hertfordshire; S. Morris, BSc, MSc, PhD, Department of Applied Health Research, University College London; J. Dixey, MD, FRCP, Department of Rheumatology, New Cross Hospital; P.L. Williams, BA, MB, BChir, FRCP, Department of Rheumatology, Medway Maritime Hospital; P. Kiely, BSc, MBBS, PhD, FRCP, Department of Rheumatology, St. Georges Healthcare NHS Trust; D.A. Walsh, PhD, FRCP, Arthritis UK Pain Centre, University of Nottingham; A. MacGregor, MA, MSc, MD, PhD, FRCP, Institute of Musculoskeletal Science, University College London; A. Young, BA, MA, MB BChir (Cantab), FRCP, ERAS/ERAN, Department of Rheumatology, St. Albans City Hospital, and the School of Life and Medical Sciences, University of Hertfordshire.
authors.forename: Elena
authors.initials: E
authors.lastname: Nikiphorou
authors.affiliation: From the Department of Applied Health Research, and the Institute of Musculoskeletal Science, University College London; Department of Rheumatology, St. Georges Healthcare National Health Service (NHS) Trust, London; Early Rheumatoid Arthritis Study (ERAS)/Early Rheumatoid Arthritis Network (ERAN), Department of Rheumatology, St. Albans City Hospital, St. Albans; School of Life and Medical Sciences, University of Hertfordshire, Hatfield; Department of Rheumatology, New Cross Hospital, Wolverhampton; Department of Rheumatology, Medway Maritime Hospital, Gillingham; Arthritis UK Pain Centre, University of Nottingham, UK.E. Nikiphorou, MBBS/BSc, MRCP, MD(Res), PGCME, FHEA, Department of Applied Health Research, University College London, and ERAS/ERAN, Department of Rheumatology, St. Albans City Hospital, and School of Life and Medical Sciences, University of Hertfordshire; S. Morris, BSc, MSc, PhD, Department of Applied Health Research, University College London; J. Dixey, MD, FRCP, Department of Rheumatology, New Cross Hospital; P.L. Williams, BA, MB, BChir, FRCP, Department of Rheumatology, Medway Maritime Hospital; P. Kiely, BSc, MBBS, PhD, FRCP, Department of Rheumatology, St. Georges Healthcare NHS Trust; D.A. Walsh, PhD, FRCP, Arthritis UK Pain Centre, University of Nottingham; A. MacGregor, MA, MSc, MD, PhD, FRCP, Institute of Musculoskeletal Science, University College London; A. Young, BA, MA, MB BChir (Cantab), FRCP, ERAS/ERAN, Department of Rheumatology, St. Albans City Hospital, and the School of Life and Medical Sciences, University of Hertfordshire.
authors.forename: Stephen
authors.initials: S
authors.lastname: Morris
authors.affiliation: From the Department of Applied Health Research, and the Institute of Musculoskeletal Science, University College London; Department of Rheumatology, St. Georges Healthcare National Health Service (NHS) Trust, London; Early Rheumatoid Arthritis Study (ERAS)/Early Rheumatoid Arthritis Network (ERAN), Department of Rheumatology, St. Albans City Hospital, St. Albans; School of Life and Medical Sciences, University of Hertfordshire, Hatfield; Department of Rheumatology, New Cross Hospital, Wolverhampton; Department of Rheumatology, Medway Maritime Hospital, Gillingham; Arthritis UK Pain Centre, University of Nottingham, UK.E. Nikiphorou, MBBS/BSc, MRCP, MD(Res), PGCME, FHEA, Department of Applied Health Research, University College London, and ERAS/ERAN, Department of Rheumatology, St. Albans City Hospital, and School of Life and Medical Sciences, University of Hertfordshire; S. Morris, BSc, MSc, PhD, Department of Applied Health Research, University College London; J. Dixey, MD, FRCP, Department of Rheumatology, New Cross Hospital; P.L. Williams, BA, MB, BChir, FRCP, Department of Rheumatology, Medway Maritime Hospital; P. Kiely, BSc, MBBS, PhD, FRCP, Department of Rheumatology, St. Georges Healthcare NHS Trust; D.A. Walsh, PhD, FRCP, Arthritis UK Pain Centre, University of Nottingham; A. MacGregor, MA, MSc, MD, PhD, FRCP, Institute of Musculoskeletal Science, University College London; A. Young, BA, MA, MB BChir (Cantab), FRCP, ERAS/ERAN, Department of Rheumatology, St. Albans City Hospital, and the School of Life and Medical Sciences, University of Hertfordshire.
authors.forename: Josh
authors.initials: J
authors.lastname: Dixey
authors.affiliation: From the Department of Applied Health Research, and the Institute of Musculoskeletal Science, University College London; Department of Rheumatology, St. Georges Healthcare National Health Service (NHS) Trust, London; Early Rheumatoid Arthritis Study (ERAS)/Early Rheumatoid Arthritis Network (ERAN), Department of Rheumatology, St. Albans City Hospital, St. Albans; School of Life and Medical Sciences, University of Hertfordshire, Hatfield; Department of Rheumatology, New Cross Hospital, Wolverhampton; Department of Rheumatology, Medway Maritime Hospital, Gillingham; Arthritis UK Pain Centre, University of Nottingham, UK.E. Nikiphorou, MBBS/BSc, MRCP, MD(Res), PGCME, FHEA, Department of Applied Health Research, University College London, and ERAS/ERAN, Department of Rheumatology, St. Albans City Hospital, and School of Life and Medical Sciences, University of Hertfordshire; S. Morris, BSc, MSc, PhD, Department of Applied Health Research, University College London; J. Dixey, MD, FRCP, Department of Rheumatology, New Cross Hospital; P.L. Williams, BA, MB, BChir, FRCP, Department of Rheumatology, Medway Maritime Hospital; P. Kiely, BSc, MBBS, PhD, FRCP, Department of Rheumatology, St. Georges Healthcare NHS Trust; D.A. Walsh, PhD, FRCP, Arthritis UK Pain Centre, University of Nottingham; A. MacGregor, MA, MSc, MD, PhD, FRCP, Institute of Musculoskeletal Science, University College London; A. Young, BA, MA, MB BChir (Cantab), FRCP, ERAS/ERAN, Department of Rheumatology, St. Albans City Hospital, and the School of Life and Medical Sciences, University of Hertfordshire.
authors.forename: Peter L
authors.initials: PL
authors.lastname: Williams
authors.affiliation: From the Department of Applied Health Research, and the Institute of Musculoskeletal Science, University College London; Department of Rheumatology, St. Georges Healthcare National Health Service (NHS) Trust, London; Early Rheumatoid Arthritis Study (ERAS)/Early Rheumatoid Arthritis Network (ERAN), Department of Rheumatology, St. Albans City Hospital, St. Albans; School of Life and Medical Sciences, University of Hertfordshire, Hatfield; Department of Rheumatology, New Cross Hospital, Wolverhampton; Department of Rheumatology, Medway Maritime Hospital, Gillingham; Arthritis UK Pain Centre, University of Nottingham, UK.E. Nikiphorou, MBBS/BSc, MRCP, MD(Res), PGCME, FHEA, Department of Applied Health Research, University College London, and ERAS/ERAN, Department of Rheumatology, St. Albans City Hospital, and School of Life and Medical Sciences, University of Hertfordshire; S. Morris, BSc, MSc, PhD, Department of Applied Health Research, University College London; J. Dixey, MD, FRCP, Department of Rheumatology, New Cross Hospital; P.L. Williams, BA, MB, BChir, FRCP, Department of Rheumatology, Medway Maritime Hospital; P. Kiely, BSc, MBBS, PhD, FRCP, Department of Rheumatology, St. Georges Healthcare NHS Trust; D.A. Walsh, PhD, FRCP, Arthritis UK Pain Centre, University of Nottingham; A. MacGregor, MA, MSc, MD, PhD, FRCP, Institute of Musculoskeletal Science, University College London; A. Young, BA, MA, MB BChir (Cantab), FRCP, ERAS/ERAN, Department of Rheumatology, St. Albans City Hospital, and the School of Life and Medical Sciences, University of Hertfordshire.
authors.forename: Patrick
authors.initials: P
authors.lastname: Kiely
authors.affiliation: From the Department of Applied Health Research, and the Institute of Musculoskeletal Science, University College London; Department of Rheumatology, St. Georges Healthcare National Health Service (NHS) Trust, London; Early Rheumatoid Arthritis Study (ERAS)/Early Rheumatoid Arthritis Network (ERAN), Department of Rheumatology, St. Albans City Hospital, St. Albans; School of Life and Medical Sciences, University of Hertfordshire, Hatfield; Department of Rheumatology, New Cross Hospital, Wolverhampton; Department of Rheumatology, Medway Maritime Hospital, Gillingham; Arthritis UK Pain Centre, University of Nottingham, UK.E. Nikiphorou, MBBS/BSc, MRCP, MD(Res), PGCME, FHEA, Department of Applied Health Research, University College London, and ERAS/ERAN, Department of Rheumatology, St. Albans City Hospital, and School of Life and Medical Sciences, University of Hertfordshire; S. Morris, BSc, MSc, PhD, Department of Applied Health Research, University College London; J. Dixey, MD, FRCP, Department of Rheumatology, New Cross Hospital; P.L. Williams, BA, MB, BChir, FRCP, Department of Rheumatology, Medway Maritime Hospital; P. Kiely, BSc, MBBS, PhD, FRCP, Department of Rheumatology, St. Georges Healthcare NHS Trust; D.A. Walsh, PhD, FRCP, Arthritis UK Pain Centre, University of Nottingham; A. MacGregor, MA, MSc, MD, PhD, FRCP, Institute of Musculoskeletal Science, University College London; A. Young, BA, MA, MB BChir (Cantab), FRCP, ERAS/ERAN, Department of Rheumatology, St. Albans City Hospital, and the School of Life and Medical Sciences, University of Hertfordshire.
authors.forename: David A
authors.initials: DA
authors.lastname: Walsh
authors.affiliation: From the Department of Applied Health Research, and the Institute of Musculoskeletal Science, University College London; Department of Rheumatology, St. Georges Healthcare National Health Service (NHS) Trust, London; Early Rheumatoid Arthritis Study (ERAS)/Early Rheumatoid Arthritis Network (ERAN), Department of Rheumatology, St. Albans City Hospital, St. Albans; School of Life and Medical Sciences, University of Hertfordshire, Hatfield; Department of Rheumatology, New Cross Hospital, Wolverhampton; Department of Rheumatology, Medway Maritime Hospital, Gillingham; Arthritis UK Pain Centre, University of Nottingham, UK.E. Nikiphorou, MBBS/BSc, MRCP, MD(Res), PGCME, FHEA, Department of Applied Health Research, University College London, and ERAS/ERAN, Department of Rheumatology, St. Albans City Hospital, and School of Life and Medical Sciences, University of Hertfordshire; S. Morris, BSc, MSc, PhD, Department of Applied Health Research, University College London; J. Dixey, MD, FRCP, Department of Rheumatology, New Cross Hospital; P.L. Williams, BA, MB, BChir, FRCP, Department of Rheumatology, Medway Maritime Hospital; P. Kiely, BSc, MBBS, PhD, FRCP, Department of Rheumatology, St. Georges Healthcare NHS Trust; D.A. Walsh, PhD, FRCP, Arthritis UK Pain Centre, University of Nottingham; A. MacGregor, MA, MSc, MD, PhD, FRCP, Institute of Musculoskeletal Science, University College London; A. Young, BA, MA, MB BChir (Cantab), FRCP, ERAS/ERAN, Department of Rheumatology, St. Albans City Hospital, and the School of Life and Medical Sciences, University of Hertfordshire.
authors.forename: Alex
authors.initials: A
authors.lastname: MacGregor
authors.affiliation: From the Department of Applied Health Research, and the Institute of Musculoskeletal Science, University College London; Department of Rheumatology, St. Georges Healthcare National Health Service (NHS) Trust, London; Early Rheumatoid Arthritis Study (ERAS)/Early Rheumatoid Arthritis Network (ERAN), Department of Rheumatology, St. Albans City Hospital, St. Albans; School of Life and Medical Sciences, University of Hertfordshire, Hatfield; Department of Rheumatology, New Cross Hospital, Wolverhampton; Department of Rheumatology, Medway Maritime Hospital, Gillingham; Arthritis UK Pain Centre, University of Nottingham, UK.E. Nikiphorou, MBBS/BSc, MRCP, MD(Res), PGCME, FHEA, Department of Applied Health Research, University College London, and ERAS/ERAN, Department of Rheumatology, St. Albans City Hospital, and School of Life and Medical Sciences, University of Hertfordshire; S. Morris, BSc, MSc, PhD, Department of Applied Health Research, University College London; J. Dixey, MD, FRCP, Department of Rheumatology, New Cross Hospital; P.L. Williams, BA, MB, BChir, FRCP, Department of Rheumatology, Medway Maritime Hospital; P. Kiely, BSc, MBBS, PhD, FRCP, Department of Rheumatology, St. Georges Healthcare NHS Trust; D.A. Walsh, PhD, FRCP, Arthritis UK Pain Centre, University of Nottingham; A. MacGregor, MA, MSc, MD, PhD, FRCP, Institute of Musculoskeletal Science, University College London; A. Young, BA, MA, MB BChir (Cantab), FRCP, ERAS/ERAN, Department of Rheumatology, St. Albans City Hospital, and the School of Life and Medical Sciences, University of Hertfordshire. eras@whht.nhs.uk.
authors.forename: Adam
authors.initials: A
authors.lastname: Young
mesh_terms: D000367:Age Factors; D000368:Aged; D001172:Arthritis, Rheumatoid / Q000150:complications / Q000175:diagnosis / Q000601:surgery*; D015331:Cohort Studies; D005260:Female; D006304:Health Status; D006801:Humans; D007902:Length of Stay; D008297:Male; D008875:Middle Aged; D019637:Orthopedic Procedures; D012042:Registries; D012720:Severity of Illness Index; D006113:United Kingdom
keywords: DISEASE MARKERS; HEMOGLOBIN; LENGTH OF STAY; ORTHOPEDIC SURGERY; RHEUMATOID ARTHRITIS; TOTAL JOINT REPLACEMENT