FACIT Fatigue in Rheumatoid Arthritis in Pfizer Trials

Rheumatoid arthritis (RA) is the most common form of inflammatory arthritis and is associated with fluctuating debilitating symptoms that confer considerable decrements to patients’ longevity and quality of life. Patient and clinician input reveal that fatigue has been identified as a common, persistent, and disabling symptom in RA, and a high priority for RA patients seeking treatment. RA patients not only consider fatigue as one of the most important aspects of their disease experience, but as an important outcome when evaluating the effectiveness of interventions. Research examining the fatigue experience of RA patients suggests that RA-associated fatigue differs from “normal” fatigue, impacts multiple domains of patients’ lives, and is under-recognized by clinicians. Patient-reported outcome (PRO) measures serve as the best method for assessing symptoms like fatigue, as its severity and impact are best known by the patient. Given the importance patients place on fatigue and its resolution as part of remission, the persistence of fatigue despite well-controlled disease activity as defined by traditional indicators, broader inclusion of fatigue measures is needed in RA clinical trials in order to better understand patients' responses to treatment. This includes determination of whether interventions can provide overall benefit to patients above and beyond the existing indicators for disease progression, symptom maintenance, and clinical remission. Precise and valid measurement of fatigue is required to fully evaluate the effects of RA interventions in clinical trials. Clinical Outcome Assessments (COAs) measure a patient’s symptoms, mental state, or the effects of a disease or condition on how the patient functions, and can be used to determine whether or not a drug has been demonstrated to provide treatment benefit.

Our research team, led by Dr. Cella at Northwestern University has extensive history working in the measurement of fatigue in RA. For example, the application of the FACIT Fatigue (Yellen, Cella, Webster, Blendowski, & Kaplan, 1997) expanded to non-cancer populations, including RA. In 2005, Cella and colleagues (Cella et al., 2005) evaluated the psychometric performance of the FACIT Fatigue using data from the Safety Trial of Adalimumab in Rheumatoid Arthritis. And in 2016, we developed the PROMIS Short Form Fatigue 10a (Kaiser, Shaunfield, Clayman, Ruderman, & Cella, 2016).