THE CONTRIBUTIONS OF DISEASE-ACTIVITY, SLEEP PATTERNS, AND DEPRESSIONTO FATIGUE IN SYSTEMIC LUPUS-ERYTHEMATOSUS - A PROPOSED MODEL

Objective, This study describes lupus fatigue multidimensionally and i ntroduces a multivariate model: Sleep problems and depression, through reciprocal effects on each other, act as mediators through which lupu s disease activity increases fatigue, Methods. Self-reported sleep pat terns, depression, and fatigue were assessed in 48 women with systemic lupus erythematosus (SLE) and 27 women from the general population. R heumatologists rated current lupus disease activity, Results, The SLE group reported greater overall fatigue than did the controls, Temporal and affective dimensions of fatigue were more differentiating than se nsory or severity dimensions, The SLE group also reported longer sleep latency and total sleep time, but not higher depression, Using 2-stag e regression, a form of structural equation modeling, the proposed lup us fatigue model was supported, Conclusion, These preliminary results describe fatigue as a multidimensional phenomenon arising out of sever al contributing factors, They suggest that fatigue treatment strategie s should address mediating processes such as sleep and depression, in addition to disease activity.