Background Patients with Systemic Lupus Erythematosus (SLE) suffer an impaired health-related quality of life (HRQoL), and the majority of them experience fatigue as a major problem. Traditionally, treatment of SLE has been symptomatic, and antimalarial agents (AMA) are considered a cornerstone of SLE treatment. In previous literature, results regarding the effect of AMA on HRQoL have been conflicting. In this study, we aimed at investigating the potential influence of AMA on SLE patients’ self-perception of HRQoL aspects.

Methods We utilised pooled baseline data from the BLISS-52 and BLISS-76 clinical trials of belimumab (N=1684). Access to data was granted by GlaxoSmithKline. The patients’ HRQoL and fatigue were self-reported using the Medical Outcomes Study short form 36 (SF-36) health survey, the functional assessment of chronic illness therapy (FACIT)-Fatigue scale and the three-level EuroQol 5 Dimension (EQ-5D) questionnaire. Minimal clinically important difference (MCID) was set to ≥5.0 points for SF-36 subscales, ≥2.5 points for SF-36 component summary scores, and ≥4 points for FACIT-Fatigue scores. The Mann-Whitney U test was used for comparisons. Linear regression models were next used to adjust for possible confounding factors; these included age, sex, ethnic origin, disease activity and duration, organ damage, corticosteroid use and use of immunosuppressants.

Results Patients receiving AMA (N=1098) performed better than patients who did not receive AMA (N=586) with regard to SF-36 physical component summary score, physical functioning, role physical, bodily pain, FACIT-Fatigue scores, EQ-5D score and EQ-5D visual analogue scale score. The difference in SF-36 physical functioning was the greatest one among the SF-36 parameters, exceeding the corresponding MCID. The association between AMA use and better physical functioning was still significant after adjustment for potential confounding factors (β=0.08; P=0.001). In this analysis, Asian patients performed better in physical functioning (β=0.07; P=0.004) while African/African American patients performed worse (β=-0.07; P=0.003). High disease activity (β=-0.09; P<0.001) and organ damage (β=-0.12; P<0.001) were also independent factors of worse physical functioning, whereas corticosteroid use independently improved the outcome (β=0.06; P=0.022).

Conclusions AMA use is associated with favourable physical functioning in patients with SLE, independently of other factors.