Advertisement

Clinical Rheumatology

, Volume 32, Issue 7, pp 1089–1093 | Cite as

Is rheumatoid factor useful in primary care? A retrospective cross-sectional study

  • Anne MillerEmail author
  • Kamal R. Mahtani
  • Margaret A. Waterfield
  • Anthony Timms
  • Siraj A. Misbah
  • Raashid A. Luqmani
Brief Report

Abstract

Rheumatoid factor (RF) is frequently tested in general practice where its utility as a diagnostic test for rheumatoid arthritis (RA) is not known. We undertook a retrospective cross-sectioal study to determine the utility and cost of RF in a primary care population. We compared RF with recorded clinical features based on the American College of Rheumatology (ACR) criteria as a diagnostic test for RA in 235 patients in general practice using receiver operating characteristic curves and calculated the cost of testing per case of RA. We analysed 36,191 RF requests made to one laboratory from 2003–2009 at a mean annual cost of £58,164 and the variation and annual cost of RF testing between 77 practices. The sensitivity and specificity of RF at the optimal cut-off value of 20 U/ml were 0.6 and 0.96 and that of two documented clinical ACR criteria were 0.9 and 0.92, respectively. No ACR criteria were documented in 150 (63.8 %) patients who had RF tested. The overall cost of RF testing per case of seropositive RA was £708.75. Of all RF requests, 66.6 % was made by GPs, 7.0 % by rheumatologists and 26.4 % by other hospital departments. The proportion of positive tests was 5.8 % in primary care and 17.7 % in rheumatology. The mean number of tests performed annually in primary care was 4.65 (SD 2.7) per 1,000 patients. RF is less sensitive for RA than clinical features in primary care and is frequently requested in cases without clinical evidence of the disease, adding to the overall cost.

Keywords

General practice Health Care Cost Rheumatoid arthritis Rheumatoid factor Sensitivity and specificity 

Notes

Acknowledgments

The authors would like to thank Dr Richard Silvester and Dr Peter Burke for providing access to data on their patients, and Carina Dunford and Jackie Masters for providing primary care demographic data.

Disclosures

None.

References

  1. 1.
    Farragher TM, Lunt M, Fu B, Bunn D, Symmons DP (2010) Early treatment with, and time receiving, first disease-modifying antirheumatic drug predicts long-term function in patients with inflammatory polyarthritis. Ann Rheum Dis 69(4):689–695PubMedCrossRefGoogle Scholar
  2. 2.
    van der Linden MP, le Cessie S, Raza K, van der Woude D, Knevel R, Huizinga TW et al (2010) Long-term impact of delay in assessment of patients with early arthritis. Arthritis Rheum 62(12):3537–3546PubMedCrossRefGoogle Scholar
  3. 3.
    Thomas MJ, Adebajo A, Chapel HM, Webley M (1995) The use of rheumatoid factors in clinical practice. Postgrad Med J 71(841):674–677PubMedCrossRefGoogle Scholar
  4. 4.
    Sinclair D, Hull RG (2003) Why do general practitioners request rheumatoid factor? A study of symptoms, requesting patterns and patient outcome. Ann Clin Biochem 40(Pt 2):131–137PubMedCrossRefGoogle Scholar
  5. 5.
    Sokka T, Pincus T (2009) Erythrocyte sedimentation rate, C-reactive protein, or rheumatoid factor are normal at presentation in 35 %–45% of patients with rheumatoid arthritis seen between 1980 and 2004: analyses from Finland and the United States. J Rheumatol 36(7):1387–1390PubMedCrossRefGoogle Scholar
  6. 6.
    Bukhari M, Lunt M, Harrison BJ, Scott DGI, Symmons DPM, Silman AJ (2002) Erosions in inflammatory polyarthritis are symmetrical regardless of rheumatoid factor status: results from a primary care-based inception cohort of patients. Rheumatology 41(3):246–252PubMedCrossRefGoogle Scholar
  7. 7.
    van Schaardenburg D, Lagaay AM, Otten HG, Breedveld FC (1993) The relation between class-specific serum rheumatoid factors and age in the general population. Br J Rheumatol 32(7):546–549PubMedCrossRefGoogle Scholar
  8. 8.
    Husby G, Gran JT, Johannessen A (1988) Epidemiological and genetic aspects of IgM rheumatoid factors. Scand J Rheumatol Suppl 75:213–218PubMedCrossRefGoogle Scholar
  9. 9.
    Nielson SF, Bojesen SE, Schnohr P, Nordestgaard BG (2012) Elevated rheumatoid factor and long term risk of rheumatoid arthritis: a prospective cohort study. BMJ 345:e5244. doi: 10.1136/bmj.e5244 CrossRefGoogle Scholar
  10. 10.
    Nishimura K, Sugiyama D, Kogata Y, Tsuji G, Nakazawa T, Kawano S et al (2007) Meta-analysis: diagnostic accuracy of anti-cyclic citrullinated peptide antibody and rheumatoid factor for rheumatoid arthritis. Ann Intern Med 146(11):797–808PubMedCrossRefGoogle Scholar
  11. 11.
    National Institute for Health and Clinical Excellence (2009) Rheumatoid arthritis: the management of rheumatoid arthritis in adults. National Institute for Health and Clinical. Excellence - Clinical Guidelines, LondonGoogle Scholar
  12. 12.
    Luqmani R, Hennell S, Estrach C, Basher D, Birrell F, Bosworth A et al (2009) British Society for Rheumatology and British Health Professionals in Rheumatology guideline for the management of rheumatoid arthritis (after the first 2 years). Rheumatology (Oxford) 48(4):436–439CrossRefGoogle Scholar
  13. 13.
    Arnett FC, Edworthy SM, Bloch DA, McShane DJ, Fries JF, Cooper NS et al (1988) The American Rheumatism Association 1987 revised criteria for the classification of rheumatoid arthritis. Arthritis Rheum 31(3):315–324PubMedCrossRefGoogle Scholar
  14. 14.
    Aletaha D, Neogi T, Silman AJ, Funovits J, Felson DT, Bingham CO 3rd et al (2010) 2010 Rheumatoid arthritis classification criteria: an American College of Rheumatology/European League Against Rheumatism collaborative initiative. Arthritis Rheum 62(9):2569–2581PubMedCrossRefGoogle Scholar
  15. 15.
    Xu D, Groom C (2009) Economic models of identification and treatment of early rheumatoid arthritis. National Audit Office, LondonGoogle Scholar
  16. 16.
    van der Weijden T, van Bokhoven MA, Dinant GJ, van Hasselt CM, Grol RP (2002) Understanding laboratory testing in diagnostic uncertainty: a qualitative study in general practice. Br J Gen Pract 52(485):974–980PubMedGoogle Scholar
  17. 17.
    Gran JT, Nordvag BY (2000) Referrals from general practice to an outpatient rheumatology clinic: disease spectrum and analysis of referral letters. Clin Rheumatol 19(6):450–454PubMedCrossRefGoogle Scholar
  18. 18.
    Suarez-Almazor ME, Gonzalez-Lopez L, Gamez-Nava JI, Belseck E, Kendall CJ, Davis P (1998) Utilization and predictive value of laboratory tests in patients referred to rheumatologists by primary care physicians. J Rheumatol 25(10):1980–1985PubMedGoogle Scholar
  19. 19.
    Spector TD, Hart DJ, Powell RJ (1993) Prevalence of rheumatoid arthritis and rheumatoid factor in women: evidence for a secular decline. Ann Rheum Dis 52(4):254–257PubMedCrossRefGoogle Scholar

Copyright information

© Clinical Rheumatology 2013

Authors and Affiliations

  • Anne Miller
    • 1
    Email author
  • Kamal R. Mahtani
    • 2
  • Margaret A. Waterfield
    • 1
  • Anthony Timms
    • 3
  • Siraj A. Misbah
    • 4
  • Raashid A. Luqmani
    • 5
  1. 1.Department of RheumatologyNuffield Orthopaedic CentreOxfordUK
  2. 2.Department of Primary Care Health SciencesUniversity of OxfordOxfordUK
  3. 3.Laboratory ImmunologyOxford University Hospitals NHS TrustOxfordUK
  4. 4.Department of Clinical ImmunologyOxford University Hospitals NHS TrustOxfordUK
  5. 5.NIHR Musculoskeletal Biomedical Research Unit, Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal ScienceUniversity of OxfordOxfordUK

Personalised recommendations