Clinical features of patients with systemic lupus erythematosus according to health-related quality of life, entity of pain, fatigue and depression: a cluster analysis.

Objectives: To identify the distribution of patients with systemic lupus erythematosus (SLE) in clusters according to the levels of health-related quality of life (HRQoL), entity of pain, fatigue and depression.

Methods: We performed a hierarchical cluster analysis. The following measures were used as clustering variables, after canonical transformation: the SF36 physical and mental component summary (PCS and MCS), the Beck Depression Inventory II (entity of depression), the Facit-Fatigue, all assessed during the last visit. Consecutive SLE patients were enrolled from two Italian cohorts. Lupus remission was retrospectively assessed over a period of 5 years before the last visit and was defined as a continuative period of no clinical disease activity according to SLEDAI2K and the maximum dose of prednisone allowed of 5 mg/day.

Results: We enrolled 130 female SLE patients. We identified three clusters. The first cluster (43 patients) was characterised by the highest levels of MCS and PCS and the lowest entity of pain, fatigue and depression. Cluster 2 (35 patients) was defined by a reduction of MCS and increase of pain, fatigue and depression; conversely, PCS levels were similar to cluster 1. In cluster 3 (52 patients) we found a reduction of MCS and increase of depression and fatigue (similar to cluster 2) but also a decrease in PCS levels and Bodily Pain (meaning increase in pain). In cluster 3 we found a decreased prevalence of remission ≥5 years.

Conclusions: Identification of clusters of patients according to HRQoL levels could be useful to improve SLE management, aiming at personalised medicine.