Systemic Lupus Erythematosus (SLE) is a multisystemic autoimmune disease that particularly affects young women during their second and third decades. In Spain, according to the EPISER1 population study (Estudio de Prevalencia e Impacto de las enfermedades reumáticas en la población adulta española, de la Sociedad Española de Reumatología), SLE prevalence is estimated at 9 per 10,000 inhabitants, although in Europe it is estimated at around 50 cases per 100,000 inhabitants.2 According to Spanish national registries, between 5 and 10 new cases per 100,000 people are detected each year.3,4

Events attributed to SLE itself and others related to the disease may impact negatively on the quality of life, employment and disability of those affected. However, there are not many studies focused on the impact that the disease may have on patients regarding those aspects. For example, in 2013 a Slovakian cohort showed that 63% of SLE patients were registered disabled and receiving some kind of pension,5 whereas in 2018 a Finnish cohort revealed that 6% of SLE workers needed a work disability authorisation in a 5 year follow-up study.6

The latest report on disability data in Spain, the “Olivenza Report” (El Informe Olivenza), edited by the State Disability Observatory and promoted by the Ministry of Health, Social Services and Equality, was published in 2017. This report states that in Spain there are 1,774,800 people with recognised disabilities between the ages of 16 and 64, representing 5.9% of the active age population. Focusing on our region, it shows that 3.2% of the general population have a recognised disability, representing 6% of the total country.7 The assessment of this situation is regulated by Royal Decree (RD) 1971/1999, of December 23, on the procedure for the recognition, declaration and qualification of the degree of disability.8 It gives the responsibility for the determination of the degree of disability to technical teams called Assessment and Guidance Teams (in Spanish Equipos de Valoración y Orientación: EVO) which are formed by, at least, one doctor, one psychologist and one social worker. They issue a proposed opinion that must necessarily contain the diagnosis, type and degree of the disability and, where appropriate, the scale scores to determine the need for help from another person and the existence of mobility difficulties to use public transport. The 33% of disability that gives the right to the recognition of the condition of a “person with disability”.9

Finally, the evaluation and certification of disability and the assignation of a pension, if applicable, is given by the National Social Security Institute of Spain, INSS (Instituto Nacional de la Seguridad Social). This certificate is the administrative recognition of disability and its purpose is to compensate for the social disadvantages that disability implies by providing access to rights and benefits of different types, with a view to providing equal opportunities. The rating of the degree of disability relates to unified technical criteria, set by the scales described in Annex I of the aforementioned Royal Decree, and will be subject to assessment of both the disabilities presented by the person, and, where appropriate, the relative social factors, among others, to their family environment and employment, educational and cultural situation, which hinder their social integration. The degree of disability will be expressed as a percentage, through the application of the scales indicated in Section (A) of the aforementioned annex.9 We therefore attempted to assess the relationship between cumulative damage regarding the affected organ and the percentage of disability recognised by the INSS in SLE patients in two Spanish hospitals of this region. In addition, we describe the employment profile between SLE patients in our cohort. It is to be noted that this is a post hoc study, not being the main objective of our initial study.

We performed a cross-sectional prospective study of SLE patients according to the 2012 Systemic Lupus International Collaborating Clinics (SLICC-2012) criteria,10 from the Rheumatology Service of two Spanish hospitals. We collected clinical and demographic data through personal interview and the SLICC/ACR questionnaire, and used a tailor-made survey to classify patients regarding a recognised disability or not, as well as their actual job.

The patient profile in our series is that of a young woman, who debuted with SLE at around 30 years of age, and who at the time of the visit has an average age of 50 years, with 15 years of disease evolution. The figures are similar in both sexes. This data corresponds to that published in other series, both national and international.2,3,11 Regarding the ethnic characteristics, given the circumstances of our location, we could not assess the existence of different interracial patterns, due to the low rate of non-Caucasians in the areas of influence of both hospitals; therefore, the data of this study could not be extrapolated to patients of other races.

Focusing on disability and the work profile, we could only analyse this data in 130 patients. Of these, 30% had experienced some degree of disability, on the understanding that we refer to people with a degree of disability greater than or equal to 33% and assimilated according to Legislative RD 1/2013. This means that the proportion of disabled people is multiplied by a factor of 10 between SLE patients, with respect to the total circumstances that are taken into account to give an official measure of disability, in our region.7 However compared to the Slovakian cohort, it doubles the percentage of SLE patients registered as disabled (63%).5 But in Spain, we have the same rate as the Finnish cohort.6 In this last report, we found that in Finland SLE itself is enough for a disability ranking, unlike Spain. In Spain, SLE itself is not recognised as a disabling disease by the National Health System. Here in Spain, the degree of disability is assessed depending on how the disease affects the worker and their ability to work. In light of this data, it could be interesting to carry out a more detailed analysis regarding the occupational profile of SLE patients as well as the disability they present.

Within our group of disabled SLE patients, 48.7% were active, 7.69% were unemployed, 12.82% were retired and 30.77% were receiving a full disability pension, and in Spain this last circumstance means they are no longer working. This data is difficult to compare with the Slovakian cohort, since profiles of disability are different5; nor to the Finnish cohort, since they studied an early-onset SLE group.6 However, compared to the Spanish data, the musculoskeletal system is the most affected both in SLE patients and in those of the general population with an official disability, which matches our own results.7 This contrasts with the fact that between disabled SLE patients, there is a higher proportion of major organs affected than in non-disabled SLE patients.

Regarding cumulative damage, we observed that the longer the disease progressed, the greater its impairment was according to the scores of the SLICC/ACR questionnaire, a fact that seems logical on the basis that lupus affects patients in an organ-specific way. It is striking that the perception of the quality of life of our sample does not correlate with the accumulated damage caused by the disease; then we see that the deterioration of an organ or system does not necessarily diminish the quality of life of our patients. Therefore, the perception of the general state of our patients does not appear to depend on the time of evolution of the disease, nor on the accumulated damage caused by it. However, there is a positive correlation in the trinomial time of evolution-disability-degree of disability, since a greater evolution relates to a greater disability and to a greater degree. In terms of disease self-perception we used a VAS scale. The mean in our patients was 3.55 with a median of 3, which indicates a good or very good assessment of the state of their disease. 57% of our sample scored 4 points or less on the scale. Overall, patients have a very low degree of accumulated damage, and also the general state perceived by patients is good, regardless of the time of disease progression.

There is a positive correlation between the percentage of recognised disability in Spain and the cumulative damage in SLE. There are no unified criteria for disability recognition or what it implies between countries. Further studies would give a broader profile of disability in SLE patients.

All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards.

Informed consent was obtained from all individual participants included in the study.

This study was funded by Generalitat Valenciana (grant number GV15/83).

The authors declare that they have no conflict of interests.