Depression, disability and sleep disturbance are the main explanatory factors of fatigue in rheumatoid arthritis: a path analysis model.

OBJECTIVES

Fatigue is one of the most prevalent and disabling symptoms among patients with rheumatoid arthritis (RA), however, it is frequently neglected by health professionals. This study aimed to develop a multidimensional explanatory model of fatigue in patients with RA as a basis for better understanding and intervention.

METHODS

This was an ancillary analysis of an observational, cross-sectional, single centre study. Patients completed a questionnaire including demographic data and measures of pain, sleep, disability, anxiety, depression, and personality. Fatigue was assessed by the Functional Assessment of Chronic Illness Therapy - Fatigue (FACIT-F). Disease activity and haemoglobin levels were assessed. Path analysis was performed to test and improve a hypothesised model for fatigue.

RESULTS

This analysis included 142 patients, with a mean (SD) age of 61.1 (11.7) years. The final path analysis model presented acceptable fit and explained 60.0% of the variance of fatigue. The predominant direct explanatory factors identified were disability (46.5%) and depression (41.2%), the latter having an additional indirect influence of 19% through disability. Age (-16.2%) and sleep disturbance (15.7%) were also directly linked to fatigue. Personality trait extroversion (-22.4%), pain (20.0%), and disease activity (14.9%) are only indirectly related to fatigue.

CONCLUSIONS

Depression, disability and sleep disturbance appear to be the main factors explaining fatigue in patients with RA. Disease activity, pain, and personality seem to play only a secondary role, extroversion being the only personality trait associated with fatigue. These findings foster a shift in the paradigm of care towards a more holistic management of fatigue, integrating adjunctive therapies beyond measures targeted solely at disease remission.