This is the first study in Venezuela to measure HRQoL of patients with SLE and to assess the impact of demographic and disease-related characteristics on HRQoL using a valid, reliable, patient-derived, and disease-specific questionnaire: the LupusQoL. Our study found that HRQoL of patients with SLE was classified as better in all domains of the LupusQoL according to the cutoff points previously established for the Venezuelan population with SLE [39]. This is in agreement with results of HRQoL, using the LupusQoL, in patients from Mexico [18] and Peru [34]. It should be taken into account that people with SLE tend to report worse HRQoL compared to general population [13, 15, 40–44], so that even with good general results HRQoL may be affected in specific domains.
Advanced age was correlated with worse HRQoL in all domains of the LupusQoL, except in “burden to others”, even though most of the correlations were weak. This was consistent with some studies [17, 18, 34, 45, 46] but no with other ones [33, 47–49]. Naturally, older patients may have worse HRQoL due to longer disease duration and higher accrual of disease-related organ damage [50], and increase comorbidities with aging [51]. More years of education was correlated with better “physical health” and “intimate relationships”. We found no description of these correlations in other studies. Longer disease duration was correlated with worse “physical health”, “pain”, and “fatigue”. Reports on the correlation between disease duration and “physical health” domain have been varied: some studies reporting no significant correlation [18, 33, 45, 47, 48, 52, 53], while others reporting correlation with better [34, 54] or worse [55] “physical health”. These discrepancies could be due to demographic and disease-related differences among different patient populations. We found no reports on the correlation between disease duration with “pain” and “fatigue” domains in previous studies. Accrued organ damage was correlated with worse HRQoL in all domains of the LupusQoL, except in “intimate relationships” and “burden to others”. Except for a study in Brazil [51], others conducted in Mexico [18, 46], Peru [34], the United States [45], the United Kingdom [17], China [41], and Japan [56] showed a similar correlation. Accrued organ damage can affect HRQoL of patients with SLE by pain due to chronic arthritis and the negative effect on physical health, emotional health, and body image due to kidney, lung, central nervous system, and skin diseases, as well as the long-term adverse effects of corticosteroids [45].
Lack of adherence to treatment in patients with SLE ranges between 3% and 76% depending on the type of medication and the population studied [57]. It is of concern that only 37% of our patients complied with treatment, in consonance with reports from Jamaica [57] and Spain [58]. Patients who fully complied with indicated treatment had higher scores in “physical health” domain compared to patients who did not comply with treatment in at least one of the prescribed medications. Intriguingly, studies from Brazil [59] and China [60] showed that patients with SLE who did not comply with treatment perceived better physical health. In our study, patients with active SLE had higher accrued organ damage score and higher prednisone indication. It is well known that disease activity and accrued organ damage are interrelated variables [42]. Also, the higher the disease activity, the greater the prednisone indication [42] and the greater the daily dosage [61].
We found that disease activity was negatively correlated with all domains of the LupusQoL, except with “intimate relationships” and “burden to others”. Active SLE patients have been reported to engage in physical activity less frequently than recommended by the World Health Organization [62]. Pain is a frequent self-reported symptom in patients with active SLE due to inflammation [63]. Almost all patients with SLE will experience muscle and/or joint pain at a given moment of their disease course, and pain has been reported to contribute to fatigue, anxiety, and depression [63]. Consequently, musculoskeletal symptoms may alter patients’ perceptions in the “physical health”, “body image”, “pain”, and “fatigue” domains [17]. The literature regarding “body image” in patients with active SLE is sparse, and it has been reported to be worse in SLE [17, 64], in accordance with our study. Our study also suggested that “planning” and “emotional health” domains were negatively influenced by the degree of disease activity. It is possible that patients with active SLE experience more fatigue and depression, which impairs their emotional well-being and planning abilities, as has been previously reported [34]. Previous studies have found that advanced age is associated with worse “intimate relationships” [17], which was not consistent with our findings. Our study also found that disease activity did not have an influence on “burden to others”, a domain mainly dependent on the level of social support available to the patient [34], and thus influenced by cultural differences among countries. In summary, our study suggests that patients with active SLE had significantly worse “physical health”, “planning”, “emotional health”, “body image”, and “fatigue” compared to patients with inactive SLE.
We found that advanced age, fewer years of education, longer disease duration, having had SLE flare-ups in the previous six months, and being unemployed were risk factors associated with some affected domains of the LupusQoL. This is consistent with results presented in a recent literature review [51]. Advanced age associates with a higher number of comorbidities. Additionally, advanced age patients have experienced longer disease duration, and longer disease duration is also associated to worse HRQoL. Patients with longer disease duration may accrue greater target-organ damage and higher risk of cardiovascular disease [51]. Consonus with our results, previous reports showed worse HRQoL in direct proportion to the number of SLE flare-ups [65, 66]. As previously reported [17], advanced age was a risk factors associated with worse “planning” and “intimate relationships” in our patients with active SLE. In turn, in patients with inactive SLE, advanced age was a risk factors associated with worse “physical health”, “intimate relationships”, “emotional health”, and “fatigue”. It is possible that, as age increases, the cumulative effect of disease morbidity, comorbidities, drug adverse effects, and worsening of body image may compromise HRQoL to a greater extent that the level of disease activity at a given point in the course of disease.
Our study has several limitations. First, the number of patients is small. Second, the study is cross-sectional, and the centers involved are tertiary reference centers limiting he generalizability of the results. Finally, it is possible that the high proportion patients who did not comply with indicated treatment in our study, in great measure derived from the critical shortage of drugs amidst the ongoing Venezuelan health crisis [67], may have affected our results. Additional studies are needed with a multicenter and longitudinal design including other potentially relevant socioeconomic factors to further test the results described in this study.