Fatigue patterns surrounding biologic disease-modifying antirheumatic drug injection in patients with an inflammatory rheumatic disease: an ecological momentary assessment study.

This study investigated severity, course and patterns of fatigue surrounding subcutaneous biological disease-modifying antirheumatic drug (bDMARD) injection in inflammatory rheumatic disease (IRD) patients using ecological momentary assessments and investigated self-reported adverse drug reactions (ADRs). In this prospective cohort study, IRD patients completed fatigue severity numeric rating scales (0-10) in web-based ecological momentary assessments in three waves of five days surrounding bDMARD injection. The course of fatigue was measured by the change in fatigue from pre-dosing to post-dosing scores and was classified as: worsening, improving or no clinically relevant change. A pattern was defined as a course of worsening, improving or no clinically relevant change in fatigue in at least two out of three waves for patients completing assessments across all three waves. ADRs could be reported on day five of each wave. In total 609 participants completed ecological momentary assessments surrounding 1541 bDMARD injections. Overall average fatigue severity across all three waves was 4.5 (± SD 2.4) and 78% experienced severe fatigue in at least one assessment. Of 398 patients completing all three waves, 61% had no clinically relevant change in fatigue in at least two out of three waves, 13% had a pattern of worsening fatigue and 18% had a pattern of improving fatigue. Of 398 patients, 36% had a consistent pattern in all three waves. IRD patients using a bDMARD may consistently experience specific fatigue patterns surrounding bDMARD administration. These patterns provide insights for clinical practice and could be used to inform patients properly.