Variations between current core outcome sets and how trials are actually measuring self-management among patients with inflammatory arthritis (IA) show the need for further established outcome domains.
In an initial step toward establishing self-management core outcome sets (COSs) for patients with inflammatory arthritis (IA), researchers found that outcome domains and measurement instruments used in self-management trials were widely diverse. This has led to a lack of consensus on defining important outcomes, therefore making it difficult to compare the effectiveness of these trials.
This systematic literature review was published in Seminars in Arthritis & Rheumatism, and further found that these outcome domains and instruments are different from those established in the current general Outcome Measures in Rheumatoid Arthritis Clinical Trials (OMERACT) COS for IA conditions.
“Further steps towards the establishment of a COS to be reported in all self-management intervention trials will enhance the relevance and the subsequent impact on the body of evidence from these trials,” the review authors said.
Following guidance from OMERACT and Core Outcome Measures in Effectiveness Trials (COMET) initiatives, the authors analyzed 38 trials published between 1988 and 2021, identifying 12 outcome domains, 39 subdomains, and 119 measurement instruments. In this review, IA included psoriatic arthritis, rheumatoid arthritis, and spondyloarthritis.
Overall, the most frequently applied outcome domain was self-management behavior, skills, and knowledge, which was mostly measured through a combination of various subdomains and was applied in 87% of included trials.
Self-efficacy, pain, physical function or disability, anxiety or depression, quality of life (QOL), fatigue, global assessment or disease activity, and coping were the most frequently applied outcome subdomains.
According to the authors, these are generally in line with outcome domains commonly used in self-management trials for people with chronic diseases, as reported in 2 previous systematic literature reviews. The frequency of application of these outcome domains varied between reviews, but that could be due to different inclusion criteria for domains within the 2 other reviews.
Further, applied measurement instruments varied within each outcome domain and were predominantly patient-reported outcomes.
Most outcomes fell into the categories of life impact—which includes the domains health-related QOL and physical function—and pathophysiological manifestations.
The 2 most frequently applied subdomains for the self-management behavior, skills, and knowledge domain, were self-efficacy and coping, which were applied in 68% and 26% of trials, respectively.
These were also 2 of the most frequently applied outcome domains for pharmaceutical interventions. However, the current COSs for these interventions do not include them.
These variations between current COSs and how trials are measuring self-management warrant further investigation into what outcome domains should be factored in to measure the effectiveness of different interventions for patients with IA.
“This review has emphasized the need for developing a COS specifically for self-management intervention trials, as this could provide consistency across outcome measures in future self-management trials, resulting in enhanced relevance and impact of the results from these trials,” the authors said.
Werdal Hansen C, Appel Esbensen B, de Thurah A, Christensen R, de Wit M, Fevejle Cromhout P. Outcome measures in rheumatology applied in self-management interventions targeting people with inflammatory arthritis a systematic review of outcome domains and measurement instruments. Seminars in Arthritis & Rheumatism. Published online March 16, 2022. doi:10.1016/j.semarthrit.2022.151995