Background: The Outcome Measures in Rheumatology (OMERACT) initiative initially defined a Contextual Factor (CF) as a “variable that is not an outcome of the study but needs to be recognized (and measured) to understand the study results.”1 Since then, the OMERACT CF Working Group has achieved consensus on an operational definition of CF’s, including three types: (i) Effect Modifying CFs (EM-CFs), (ii) Outcome Influencing CFs (OI-CFs), and (iii) Measurement Affecting CFs (MA-CFs)². The working group defines an OI-CF as a variable that is prognostically important as it influences the outcome and, hence, such variables may confound the results of longitudinal observational studies (LOS) or quasi-controlled trials if they lead to the exposure and thus are important to take into account in the analyses (i.e. in order to de-confound the inferential analyses). Hence, variables commonly adjusted for in LOS are likely to be potentially important OI-CFs. For this review, we will focus on rheumatoid arthritis (RA) as it is one of the most commonly investigated diseases in rheumatology
Section for Biostatistics and Evidence-Based Research (B&EBR)
Background: Contextual factors (CFs) are important for interpreting the results of trials. The so-called ‘effect modifying contextual factors’ (EM-CFs) are factors modifying the treatment effect in a trial. To ensure consistent reporting and stratification of trial results, allowing for future evidence synthesis, a consensus-based set of important EM-CFs is needed. A first step involves collecting candidate EM-CFs.
Background: The Outcome Measures in Rheumatology (OMERACT) Contextual Factor Working Group defines Outcome Influencing Contextual Factors (OI-CFs) as prognostic factors of relevance to longitudinal observational studies (LOS) and hence, potential confounders. The working group aims to select these potential confounders to be collected in all studies to improve interpretation of study results in rheumatology.
Clinical Research Unit
Persistent pain is a common symptom in patients with psoriatic arthritis (PsA) and may be caused by ongoing inflammation in joints, entheses and tendons. In some cases, ongoing pain may be due to “sensitization” of nerve cells involved in pain processing, which leads to increased pain perception even in the absence of disease activity. We aim to study pain mechanisms in relation to disease activity measured by clinical examination and ultrasound (US) of several musculoskeletal structures, in patients with PsA. Further, we intend to clarify if assessment of pain mechanisms and US are valuable tools to predict response to anti-inflammatory treatment in PsA.
The study is enrolling PsA patients until February 2017