Risk of polymyalgic-onset inflammatory arthritis in patients initially diagnosed with polymyalgia rheumatica

Max Yates, Jalpa Kotecha, Karly Graham, Richard A. Watts, Robert Luben, Kay-Tee Khaw, Alex MacGregor

Research output: Contribution to journalAbstractpeer-review


Background: Previous studies from secondary care have suggested that inflammatory arthritis develops in up to 20.2% of patients with PMR within 12 months of disease onset. However, many cases of PMR are exclusively managed in the community and the true risk of subsequent inflammatory arthritis is unknown. This study aimed to determine the rate at which new cases of PMR transform to inflammatory arthritis in a population sample and to assess whether clinical factors at presentation might identify those at risk of subsequent inflammatory arthritis.

Methods: The study was conducted in participants in the European Prospective Investigation into Cancer and Nutrition (EPIC) Norfolk. The cohort was established with 30 441 healthy volunteers ages 40–79 years between 1993 and 1997, recruited from 35 general practice sites across Norfolk, UK. New cases of PMR diagnosed on or after 1 January 2002 were identified by electronic record linkage, International Classification of Diseases, Tenth Revision codes and follow-up questionnaires. Inflammatory arthritis was identified from hospital records review. The end date for follow-up was 31 January 2015. Survival analysis (accounting for censoring from loss to follow-up and death) was used to calculate the cumulative risk of inflammatory arthritis.

Results: A total of 298 incident diagnoses of PMR (72.5% female) were identified in the cohort. The median age at diagnosis was 75.6 years. The maximum follow-up period was 13 years (median 4.82). During 1573.6 person-years of follow-up, 31 (10.4%) participants (19 female) were diagnosed with inflammatory arthritis by a rheumatologist. The cumulative risk of new-onset inflammatory arthritis at 1, 2, 5 and 10 years was 3.9% (95% CI 2.2, 6.9), 7.4% (4.8, 11.2), 9.7% (6.6, 14.0) and 16.0% (10.6, 23.8), respectively. Males were at greater risk of developing inflammatory arthritis compared with females in the first 5 years [cumulative risk for males at 1 and 5 years: 8.9% (95% CI 4.4, 17.8) and 15.7% (9.2, 26.0), respectively; cumulative risk for females: 2.0% (95% CI 0.8, 5.2) and 7.3% (4.3, 12.3)]. There was a trend towards a greater risk of inflammatory arthritis in those with a younger age at PMR onset. The majority of participants with inflammatory arthritis were RF negative (72.7%).

Conclusion: These are the first estimates from a population study that assessed the risk of inflammatory arthritis developing after a diagnosis of PMR. Patients with PMR are at sustained risk of developing inflammatory arthritis up to 10 years after diagnosis. The data suggest that males and those of younger age are at a greater risk. The finding that 10.4% of participants with PMR at baseline subsequently develop inflammatory arthritis suggests a subset of patients with PMR could benefit from the early use of DMARDs.
Original languageEnglish
Pages (from-to)i50-i51
Number of pages2
Issue numbersuppl_1
Publication statusPublished - Apr 2016
EventAnnual Meeting of the British Society for Rheumatology, British Health Professionals in Rheumatology and the British Society for Paediatric and Adolescent Rheumatology - Glasgow, United Kingdom
Duration: 26 Apr 201628 Apr 2016

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