Introduction
Systemic lupus erythematosus (SLE) is a chronic, complex disease with an unpredictable course and a wide range of manifestations and organ involvement.1
In the last decades, better control of disease activity has been associated with the improvement of long-term prognosis of patients with SLE, in terms of damage accrual, hospitalisations, comorbidities and mortality.2
However, this has not been paralleled by a similar improvement in patients’ Health-Related Quality of Life (HRQoL). HRQoL of SLE patients is consistently lower not only when compared with that of matched healthy subjects,3 but also when compared with patients with other chronic diseases.4–6
The relationship between disease activity, organ damage and HRQoL in SLE is controversial and using global activity and damage indices as predictors of quality of life can hinder the correct evaluation of the impact of the disease on patient’s life.7
Several studies have demonstrated that the correlation between SLEDAI and SLICC-Damage Index with Patient-Reported Outcomes (PROs) is often weak.8–10
Actually, global disease activity and damage indices give more weight to the items relative to the most severe disease manifestations, like renal and neuropsychiatric ones, which are the major concerns in the management of SLE from the physician’s point of view. On the other hand, patients’ major concerns are relative to symptoms like pain and fatigue and to the degree of functioning in their daily living.11–13
In fact, musculoskeletal manifestations in SLE seem to have a stronger association with PROs results, particularly with the physical aspects of HRQoL.14 15
Just to make the picture even more complex, HRQoL is often investigated by generic PROs that may not be able to explore all aspects that are relevant for SLE patients, whereas disease-specific questionnaires seem to be more sensitive to changes in disease activity.10
However, some data in the literature show that in the life of a patient with SLE, a link exists between the course of the disease and the patient’s perception of health status. Some studies seem to demonstrate that patients with a stable well-controlled disease for a long period of time have a better HRQoL, particularly in the physical domains.16 17
So, our hypothesis is that in such a complex disease, with an unpredictable course and a great variety of clinical manifestations, the course of the disease over time, rather than disease activity in a single moment, could have a more significant impact on patients’ HRQoL.
Barr et al18 have historically defined three main different courses of the disease over time: a relapsing-remitting (RR) course, a long quiescent (LQ) and a chronically active (CA) disease.
Therefore, the goal of this study is to assess the impact of the three different patterns of disease activity on HRQoL, evaluated by both generic and disease-specific PROs, in a monocentric cohort of SLE patients.