315 Searching for a prodrome for rheumatoid arthritis in the primary care record: a clinical practice research datalink study

Muller, Sara; Hider, Samantha; Machin, Annabelle; Stack, Rebecca; Hayward, Richard; Raza, Karim; Mallen, Christian

Abstract

Background: Outcomes in rheumatoid arthritis (RA) are improved by early treatment with disease modifying anti-rheumatic drugs (DMARD). This requires prompt recognition of symptoms when patients present to their general practitioner (GP) in order to institute a referral. However, presentation is not always classical and patients may be difficult to identify. We have investigated whether it is possible to increase the index of suspicion for early RA by defining a prodromal syndrome for RA in the electronic primary care records.

Methods: We conducted a case-control study in the Clinical Practice Research Datalink (CPRD). Cases were those with definite RA diagnosed between 2007 and 2012, according to a previously published definition. Controls were matched to cases on age, gender and general practice, and did not have any record of inflammatory arthritis. For each case, an index date was created - date of the first indication that RA was suspected (read code for RA or other inflammatory arthritis, DMARD prescription, referral to rheumatology). This was used as the start of the look-back period. We compared rates of consultation in cases and controls in the six months prior to the index date and looked for a difference in the rate of two types of exposure between cases and controls: empirical exposures (3-character read codes seen in ≥ 5% of cases or controls); pre-defined exposures (compiled from literature and expert opinion and defined by a list of read codes).

Results: We identified 3577 definite RA cases, matched to 14287 controls. We found a 79% (95% CI 76%, 81%) increased rate of consulting in cases (mean 19.0 consultations per year) compared to controls (10.7). As expected, in the pre-defined analyses, those with RA were more likely to have codes for joint specific symptoms (e.g. hand problems, odds ratio (OR): 44.14; 95% CI 31.80, 61.25), systemic problems (e.g. fatigue: 1.59; 1.24, 2.03) and other musculoskeletal syndromes (carpal tunnel: 8.50; 5.72, 12.62). When considering empirical exposures, those with RA were more likely to have received Read codes for joint and soft tissue disorders, but most exposures associated with RA were general codes relating to the patient having been reviewed (e.g. complaining of a general symptom: 2.53; 2.03, 3.16).

Conclusion: In the six months prior to a diagnosis of RA, patients consulted their GP at a much higher rate than those without inflammatory arthritis. Symptoms previously described as being associated with the onset of RA were more common in those who went on to receive an RA diagnosis. We did not find any new presentations associated with RA from our empirical analyses. Dissemination of these results to the general practice community could help to expedite referrals to specialist services by facilitating early recognition of RA symptoms, potentially improving patient outcomes.

Citation

Muller, S., Hider, S., Machin, A., Stack, R., Hayward, R., Raza, K., & Mallen, C. (2018). 315 Searching for a prodrome for rheumatoid arthritis in the primary care record: a clinical practice research datalink study. Rheumatology, 57(suppl_3), https://doi.org/10.1093/rheumatology/key075.539

• Journal Article Type: Conference Paper
• Online Publication Date: Apr 25, 2018
• Publication Date: Apr 1, 2018
• Deposit Date: Jun 27, 2023
• Journal: Rheumatology
• Print ISSN: 1462-0324
• Electronic ISSN: 1462-0332
• Publisher: Oxford University Press
• Peer Reviewed: Peer Reviewed
• Volume: 57
• Issue: suppl_3
• DOI: https://doi.org/10.1093/rheumatology/key075.539
• Keywords: Pharmacology (medical); Rheumatology