Protocol for a population-based Ankylosing Spondylitis (PAS) cohort in Wales

<p>Abstract</p> <p>Background</p> <p>To develop a population-based cohort of people with ankylosing spondylitis (AS) in Wales using (1) secondary care clinical datasets, (2) patient-derived questionnaire data and (3) routinely-collected information in order to examine disease history and the health economic cost of AS.</p> <p>Methods</p> <p>This data model will include and link (1) secondary care clinician datasets (i.e. electronic patient notes from the rheumatologist) (2) patient completed questionnaires (giving information on disease activity, medication, function, quality of life, work limitations and health service utilisation) and (3) a broad range of routinely collected data (including; GP records, in-patient hospital admission data, emergency department data, laboratory/pathology data and social services databases). The protocol involves the use of a unique and powerful data linkage system which allows datasets to be interlinked and to complement each other.</p> <p>Discussion</p> <p>This cohort can integrate patient supplied, primary and secondary care data into a unified data model. This can be used to study a range of issues such as; the true economic costs to the health care system and the patient, factors associated with the development of severe disease, long term adverse events of new and existing medication and to understand the disease history of this condition. It will benefit patients, clinicians and health care managers. This study forms a pilot project for the use of routine data/patient data linked cohorts for other chronic conditions.</p

Influence of environmental factors on disease activity in spondyloarthritis: A prospective cohort study

Objective. Spondyloarthritis (SpA) is a complex inflammatory disorder. We investigated the influence of environmental factors on SpA disease activity. Methods. A prospective cohort of adults with SpA was followed for 3 years. Patients logged on to a secured Website every 3 months to complete a questionnaire. They reported whether they had been exposed to environmental factors such as stressful or traumatic life events, infections, or vaccinations. Outcome variables included the Bath Ankylosing Spondylitis Disease Activity Index (BASDAI), the Bath Ankylosing Spondylitis Functional Index (BASFI), and pain and patient global assessment (PGA) on visual numerical scales (each rated 0-10). Analyses were performed using a generalized estimating equation for repeated measures, adjusted for the outcome variable collected by the previous questionnaire. Results. In total, 272 patients were included in the analysis, completing the questionnaire on 2240 occasions. The average time (mean \ub1 SD) between 2 connections to the Website was 4.0 \ub1 2.0 months. Occurrence of life events was followed by an increase of 0.5 (95% CI 0.4-0.7) in the BASDAI, 0.5 (95% CI 0.3-0.6) in the BASFI, 0.7 (95% CI 0.5-0.9) in the PGA, and 0.8 (95% CI 0.6-1.0) for pain (p &lt; 0.0001 for all variations). A moderately statistically significant link was found between vaccination and an elevation of the BASDAI of 0.3 (95% CI 0.0-0.5; p = 0.032). No influence of other factors was detected. Conclusion. This prospective study in a dedicated SpA cohort shows for the first time a link between stressful events and disease activity. Although this link was statistically highly significant, its clinical meaning remains to be determined because the average magnitude of variation of the different variables studied was rather mild. The Journal of Rheumatology Copyright \ua9 2013. All rights reserved