Fatigue is associated with quality of life in sarcoidosis patients

Background: Fatigue is one of the core symptoms of sarcoidosis patients. Although it is known that fatigue affects quality of life (QOL) in other patient groups, this relationship has never been studied in sarcoidosis patients using a reliable and valid fatigue scale and a multidimensional QOL instrument. The present cross-sectional study among sarcoidosis patients attempts to gain more insight into this relationship. Methods: One hundred forty-five sarcoidosis patients of an outpatient pulmonary clinic in Zagreb, Croatia, completed the Fatigue Assessment Scale (FAS) and QOL scale (World Health Organization Quality of Life Assessment Instrument-100) between January 2002 and May 2004. Clinical parameters were derived from the patients' medical files. Results: Tired patients reported a worse QOL in all domains and fatigue negatively predicted all QOL domains by means of multivariate regression analyses (beta values ranging from - 0.31 to - 0.64, all p < 0.001). Corticosteroid use was not a predictor of QOL. Diffusion capacity of the lung for carbon monoxide was the only clinical parameter associated with a QOL domain, namely level of independence. Conclusions: Fatigue was related to all QOL domains. Furthermore, standard clinical parameters were not associated with fatigue or QOL, except for level of independence. If these results were to be replicated in a prospective study, fatigue as measured by the FAS could be a good indicator of QOL in sarcoidosis patients.