Article Text

PDF
SAT0354 Validity of Gout Diagnosis in Swedish Primary and Secondary Care
  1. M.I. Dehlin,
  2. K. Stasinopoulou,
  3. L. Jacobsson
  1. Dept of rheumatology and inflammation research, Institution of Medicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden

Abstract

Background To diagnose gout, the golden standard is detection of monosodium urate (MSU) crystals in synovial fluid [1,2]. However, while some gout classification criteria include this variable, most gout diagnoses are based on clinical features [3,4]. This discrepancy between clinical practice and classification criteria hampers gout epidemiological studies.

Objectives The objective was to validate gout diagnoses (ICD-10 gout codes) in primary care (PC) and secondary care relative to five classification criteria (Rome [5], New York [6], ARA [7], Mexico [8], and Netherlands [9]). The frequency with which MSU crystal identification was used to establish a gout diagnosis was also determined.

Methods In total, 394 patients with ≥1 ICD-10 gout diagnoses in 2009–2013 in Gothenburg, Sweden were identified from medical records of two PCs (n=262) and one secondary care center (n=132). Medical records were assessed for all classification criteria.

Results PC patients met criteria cut-offs more frequently when ≥2 gout diagnoses were made. However, even then, few PC patients met the Rome and New York cut-offs (19% and 8%, respectively). ARA, Mexico, and Netherlands cut-offs were met more frequently by PC patients with ≥2 gout diagnoses (54%, 81%, and 80%, respectively). Mexico and Netherlands cut-offs were met frequently by the rheumatology department patients even when patients with only 1 gout diagnosis were included (80% and 71%, respectively). MSU crystal analysis served to establish gout diagnosis in only 27% and 2% of rheumatology department and PC cases, respectively.

Conclusions If a patient is deemed to have gout when ≥2 PC or ≥1 rheumatology-center visits associate with an ICD-10 gout code, the positive predictive value of this variable relative to the Mexico and Netherlands classification criteria was ≥80% in both PC and rheumatology care settings in Sweden. MSU crystal identification was rarely used to establish gout diagnoses.

References

  1. McCarty DJ et al: Identification of urate crystals in gouty synovial fluid. Ann Intern Med 1961, 54:452-460.

  2. Pascual E et al: Synovial fluid analysis for diagnosis of intercritical gout. Ann Intern Med 1999, 131(10):756-759.

  3. Choi HK et al: Alcohol intake and risk of incident gout in men: a prospective study. Lancet 2004, 363(9417):1277-1281.

  4. Choi HK et al: Obesity, weight change, hypertension, diuretic use, and risk of gout in men: the health professionals follow-up study. Arch Intern Med 2005, 165(7):742-748.

  5. Kellgren J H JM et al: The epidomiology of chronic rheumatism. Oxford: Blackwell Scientific 1963.

  6. Decker J: Report from the subcommittee on diagnostic criteria for gout. In: Bennett PH, Wood PHN, eds. Population studies of the rheumatic diseases. Proceedings of the Third International Symposium, New York, June 5-10, 1966. Amsterdam: Excerpta Medica Foundation, 1968, 1968:385-387.

  7. Wallace SL et al: Preliminary criteria for the classification of the acute arthritis of primary gout. Arthritis Rheum 1977, 20(3):895-900.

  8. Pelaez-Ballestas I et al: Diagnosis of chronic gout: evaluating the american college of rheumatology proposal, European league against rheumatism recommendations, and clinical judgment. J Rheumatol 2010, 37(8):1743-1748.

  9. Janssens HJ et al: A diagnostic rule for acute gouty arthritis in primary care without joint fluid analysis. Arch Intern Med 2010, 170(13):1120-1126.

Disclosure of Interest None declared

Statistics from Altmetric.com

Request permissions

If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.