Cross-sectional study of the effects of self-efficacy on fatigue and pain interference in black women with systemic lupus erythematosus: the role of depression, age and education

Objective While fatigue and pain are pervasive symptoms in SLE, self-efficacy can mitigate their intensity and impact on patients' daily activity. We examined the relationships of these domains and their interactions with demographics and depression in black women with SLE. Methods This is a cross-sectional analysis of data collected among 699 black women with SLE. We used validated, self-reported measures of fatigue, pain interference, symptom self-efficacy, treatment self-efficacy and depression. Linear regression analyses were conducted to examine the relationships between each outcome (fatigue and pain interference) and each predictor (symptom self-efficacy and treatment self-efficacy), and the interaction of demographics and depression. Results We found inverse associations between fatigue and each of symptom self-efficacy (slope -0.556, p<0.001) and treatment self-efficacy (slope -0.282, p<0.001), as well as between pain interference and each of symptom self-efficacy (slope -0.394, p<0.001) and treatment self-efficacy (slope -0.152, p<0.001). After adjusting for confounders, symptom self-efficacy remained significantly associated with each outcome (adjusted slope -0.241 (p<0.001) and -0.103 (p=0.008) for fatigue and pain, respectively). The amount of decrease in fatigue and pain interference differed by depression severity (p<0.05 for the interaction of symptom self-efficacy and depression). The difference in fatigue by depression widened as symptom self-efficacy increased; the adjusted fatigue scores for moderate/severe depression compared with no depression were 6.8 and 8.7 points higher at mean and high symptom self-efficacy, respectively (p<0.001). Age and education significantly changed the relationship between outcomes and self-efficacy. Conclusions Symptom self-efficacy and treatment self-efficacy were inversely related to fatigue and pain interference in black women with SLE. Depression disproportionately increased the intensity of these outcomes. While older women with low symptom self-efficacy reported disproportionately higher pain interference, those with higher education and mean or high levels of symptom self-efficacy reported lower pain interference. These findings may help predict who might benefit most from self-efficacy-enhancing interventions.