Article Text
Abstract
Objective Accurate disease assessment remains challenging in complex and heterogeneous diseases such as systemic lupus erythematosus (SLE). Systemic Lupus Erythematosus Disease Activity Score (SLE-DAS) is a recently developed disease activity score for SLE patients, followed by a successful definition of SLE-DAS based low disease activity (LDA). It was our aim to assess the impact of SLE-DAS LDA on health-related quality of life (HRQoL).
Methods A single-centre cross-sectional study on patients with a confirmed diagnosis of SLE was conducted. HRQoL was measured using the Medical Outcomes Measures Study 36-item short health survey (SF-36v2) and Lupus Quality of Life (LupusQoL) Questionnaire. Disease activity was measured using SLE disease activity index 2000 (SLEDAI-2K) and SLE-DAS, respectively. LDA was assessed by SLE-DAS LDA. For fulfilling SLE-DAS LDA SLE-DAS ≤2.48 and prednisolone dose ≤7.5mg/day were required.
Results A total of 61 SLE patients were enrolled. 96.7% (n=59) were female, aged between 18 and 65 years. According to the level of disease activity assessed by SLEDAI-2K, we found that 23% (n=14) were in remission, 60.7% (n=14) were mildly active, 14.8% (n=9) were moderately active and 1.6% were highly active. The majority of patients (n=37; 60.7%) fulfilled the SLE-DAS LDA definition. SLE-DAS demonstrated a strong correlation with SLEDAI-2K (r=0.7206, (95%CI = 0.5727 to 0.8231), R2 = 0.5193, p<0.001) (figure 1). All SF-36 domains were affected, especially General Health GH 46.75 (SD ±21.21), followed by Vitality (VT) 51.74 (SD ±24.89) and Bodily Pain (BP) 57.82 (SD ±30.28). The Physical Component Summary (PCS) and Mental Component Summary (MCS) scores were also reduced. Likewise, all LupusQoL domains were affected, most notably Intimate relationships 54.91 (SD±37.79), followed by Burden to others 58.33 (SD±31.95) and Body image 60.33 (SD±25.78). Individual SF-36 and LupusQoL domain scores were not significantly higher (better) in patients who fulfilled criteria for LDA (figure 2).
Conclusions SLE-DAS is a valid and useful tool for disease activity measurement in SLE patients. HRQoL, by and large, correlates poorly with disease activity and these results emphasize its importance as an independent outcome parameter.
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