JMIR Publications

ABSTRACT

Background:

The cardinal feature of osteoarthritis (OA) is pain. Whilst heterogeneity in pain and function have been demonstrated in the long-term course of OA, the more proximate determinants of acute flare-ups, remain less clear. How short-term intermittent or transient exposures trigger acute flare-ups has important implications for effective and sustainable self-management strategies.

Objective:

The primary objective of this study is to identify potential triggers of acute flares in knee OA. Secondary objectives are to determine their course and consequences and describe high-risk participant profiles.

Methods:

Web-based case-crossover study. The study aims to recruit 620 community-dwelling adults aged ≥40 years, resident in England, and who have knee pain, with or without a recorded diagnosis of knee OA, and no pre-existing diagnosis of inflammatory arthropathy. Participants will be recruited via three routes, (i) general practice registers, (ii) offline community advertisement, and (iii) online social media advertisement. By using questionnaires comparing periods prior to participants’ self-reported flare-up episodes (hazard periods) with periods during the study when their knee OA symptoms are stable (control periods), triggers preceding flare-ups will be identified and examined using conditional logistic regression. Time-to-resolution of flare-up will be examined by monitoring people’s daily pain, bothersomeness, and medication usage until the participant reports their flare-up episode ends. Rates of flare-ups will be examined across different participant and flare characteristics using regression models to identify high-risk participant profiles. A study-specific Patient Advisory Group (PAG) is providing suggestion, input and ongoing support for all stages of the research process.

Results:

Participant recruitment opened in July 2018 and is anticipated to continue for six months. The study results will be disseminated through a number of channels, including, relevant national/international conferences and peer-reviewed publication in a medical journal, via advocacy/charity organisations, such as Versus Arthritis and across social media. Findings will be fed back to members of our PAG, study participants and clinicians from participating primary care general practices. The PAG will also take an active role in the overall dissemination strategy.

Conclusions:

This study will provide empirical evidence to help patients identify common knee OA flare triggers and provide healthcare professionals with questions to identify patients at most risk of frequent flare-ups.