Optimising use of electronic health records to describe the presentation of rheumatoid arthritis in primary care: a strategy for developing code lists

Background Research using electronic health records (EHRs) relies heavily on coded clinical data. Due to variation in coding practices, it can be difficult to aggregate the codes for a condition in order to define cases. This paper describes a methodology to develop ‘indicator markers’ found in patients with early rheumatoid arthritis (RA); these are a broader range of codes which may allow a probabilistic case definition to use in cases where no diagnostic code is yet recorded. Methods We examined EHRs of 5,843 patients in the General Practice Research Database, aged ≥30y, with a first coded diagnosis of RA between 2005 and 2008. Lists of indicator markers for RA were developed initially by panels of clinicians drawing up code-lists and then modified based on scrutiny of available data. The prevalence of indicator markers, and their temporal relationship to RA codes, was examined in patients from 3y before to 14d after recorded RA diagnosis. Findings Indicator markers were common throughout EHRs of RA patients, with 83.5% having 2 or more markers. 34% of patients received a disease-specific prescription before RA was coded; 42% had a referral to rheumatology, and 63% had a test for rheumatoid factor. 65% had at least one joint symptom or sign recorded and in 44% this was at least 6-months before recorded RA diagnosis. Conclusion Indicator markers of RA may be valuable for case definition in cases which do not yet have a diagnostic code. The clinical diagnosis of RA is likely to occur some months before it is coded, shown by markers frequently occurring ≥6 months before recorded diagnosis. It is difficult to differentiate delay in diagnosis from delay in recording. Information concealed in free text may be required for the accurate identification of patients and to assess the quality of care in general practice

Clinical significance of IgA rheumatoid factor subclasses in rheumatoid arthritis

OBJECTIVE: IgA rheumatoid factor (RF) is associated with greater disease activity and radiological progression in rheumatoid arthritis (RA). We examined whether measuring IgA RF subclasses gives additional clinically relevant information. METHODS: Total IgA RF plus IgA1 RF and IgA2 RF subclasses were estimated by ELISA using rabbit IgG as antigen in 144 patients with established RA. Disease activity was assessed by Disease Activity Score and Health Assessment Questionnaire; the acute phase response was assessed by C-reactive protein levels and joint damage by the Larsen score. RESULTS: Fifty percent of patients had elevated total IgA RF, 60% elevated IgA1 RF, and 50% elevated IgA2 RF. There were significant correlations between total IgA RF and both IgA RF subclasses (p < 0.0001). Measures of disease activity, the acute phase response, and joint damage were all significantly higher (p < 0.001 in each case) in patients with elevated total IgA RF and both IgA RF subclasses compared with RF negative cases. Disease duration influenced the relationship of IgA RF subclasses to joint damage. The Larsen score was only significantly higher in late disease (duration 5 years or more) in both IgA1 RF and IgA2 RF positive patients. CONCLUSION: We found IgA RF positive patients have more aggressive RA than negative cases. Measuring IgA1 RF and IgA2 RF subclasses did not give more information about clinical status than measuring total IgA RF alone

Rheumatoid factor isotypes, disease activity and the outcome of rheumatoid arthritis: comparative effects of different antigens

To access publisher full text version of this article. Please click on the hyperlink in Additional Links fieldThe value of rheumatoid factor (RF) isotypes for assessing rheumatoid arthritis (RA) remains debatable. We investigated whether using different antigens to measure RF alters the relationships between RF isotypes and clinical variables. The association between IgA and IgM RF, disease activity, and cumulative anatomical joint damage in RA was studied in 140 patients. The RF isotypes were measured using both rabbit IgG and horse IgG as antigens. Cumulative anatomical damage was assessed radiologically using Larsen's score and disease activity was determined by C-reactive protein (CRP), the health assessment questionnaire (HAQ), and a combined disease activity score (DAS). Patients positive for IgA RF and IgM RF against rabbit IgG had significantly higher disease activity and more radiological damage than negative patients. With horse IgG as antigen these differences were smaller or absent. Patients positive for only IgM RF had milder disease than patients positive for IgA RF with or without IgM RF. The clinical relationships of RF isotypes are related to the antigen used. Measuring IgA RF against rabbit IgG provides most information about disease activity, functional impairment and joint damage

Development of a self-administered early inflammatory arthritis detection tool

<p>Abstract</p> <p>Background</p> <p>Barriers to care limit the potential benefits of pharmacological intervention for inflammatory arthritis. A self-administered questionnaire for early inflammatory arthritis (EIA) detection may complement contemporary triage interventions to further reduce delays to rheumatologic care. The objective of this study was to develop a self-administered EIA detection tool for implementation in pre-primary care settings.</p> <p>Methods</p> <p>A core set of dimensions and constructs for EIA detection were systematically derived from the literature and augmented by investigative team arbitration. Identified constructs were formulated into lay language questions suitable for self-administration. A three-round Delphi consensus panel of EIA experts and stakeholders evaluated the relevance of each question to EIA detection and suggested additional items. Questions accepted by less than 70% of respondents in rounds one or two were eliminated. In round three, questions accepted by at least 80% of the panel were selected for the tool.</p> <p>Results</p> <p>Of 584 citations identified, data were extracted from 47 eligible articles. Upon arbitration of the literature synthesis, 30 constructs encompassing 13 dimensions were formulated into lay language questions and posed to the Delphi panel. A total of 181 EIA experts and stakeholders participated on the Delphi panel: round one, 60; round two, 59; and, round three, 169; 48 participated in all three rounds. The panel evaluated the 30 questions derived from the literature synthesis, suggested five additional items, and eliminated a total of 24. The eleven-question instrument developed captured dimensions of articular pain, swelling, and stiffness, distribution of joint involvement, function, and diagnostic and family history.</p> <p>Conclusions</p> <p>An eleven-question, EIA detection tool suitable for self-administration was developed to screen subjects with six to 52 weeks of musculoskeletal complaints. Psychometric and performance property testing of the tool is ongoing.</p