Time to diagnosis in systemic lupus erythematosus: Associated factors and its impact on damage accrual and mortality. Data from a multi-ethnic, multinational Latin American lupus cohort.

BACKGROUND: Systemic lupus erythematosus (SLE) often mimics symptoms of other diseases, and the interval between symptom onset and diagnosis may be long in some of these patients. Aims: To describe the characteristics associated with the time to SLE diagnosis and its impact on damage accrual and mortality in patients with SLE from a Latin American inception cohort. METHODS: Patients were from a multi-ethnic, multi-national Latin-American SLE inception cohort. All participating centers had specialized lupus clinics. Socio-demographic, clinical/laboratory, disease activity, damage, and mortality between those with a longer and a shorter time to diagnosis were compared using descriptive statistical tests. Multivariable Cox regression models with damage accrual and mortality as the end points were performed, adjusting for age at SLE diagnosis, gender, ethnicity, level of education, and highest dose of prednisone for damage accrual, plus highest dose of prednisone, baseline SLEDAI, and baseline SDI for mortality. RESULTS: Of the 1437 included in these analyses, the median time to diagnosis was 6.0 months (Q1-Q3 2.4-16.2); in 721 (50.2%) the time to diagnosis was longer than 6 months. Patients whose diagnosis took longer than 6 months were more frequently female, older at diagnosis, of Mestizo ethnicity, not having medical insurance, and having "non-classic" SLE symptoms. Longer time to diagnosis had no impact on either damage accrual (HR 1.09, 95% CI 0.93-1.28, p = 0.300) or mortality (HR 1.37, 95% CI 0.88-2.12, p = 0.200). CONCLUSIONS: In this inception cohort, a maximum time of 24 months with a median of 6 months to SLE diagnosis had no apparent negative impact on disease outcomes (damage accrual and mortality).

Predictors of severe hemolytic anemia and its impact on major outcomes in systemic lupus erythematosus: Data from a multiethnic Latin American cohort.

OBJECTIVE: To determine the predictors of the occurrence of severe autoimmune hemolytic anemia (AIHA) and its impact on damage accrual and mortality in SLE patients. METHODS: Factors associated with time to severe AIHA (hemoglobin level ≤7 g/dL) occurring from the onset of SLE symptoms were examined by Cox proportional hazards regressions. The association of severe AIHA with mortality was examined by logistic regression analyses while its impact on damage was by negative binomial regression. RESULTS: Of 1,349 patients, 49 (3.6%) developed severe AIHA over a mean (SD) follow-up time of 5.4 (3.8) years. The median time from the first clinical manifestation to severe AIHA was 111 days (IQR 43-450). By multivariable analysis, male sex (HR 2.26, 95% CI 1.02-4.75, p = 0.044), and higher disease activity at diagnosis (HR 1.04, 95% CI 1.01-1.08, p = 0.025) were associated with a shorter time to severe AIHA occurrence. Of the SLEDAI descriptors, only hematologic (leukopenia and/or thrombocytopenia) showed a certain trend toward significance in the multivariable analysis (HR 2.36, 95% CI 0.91-6.13, p = 0.0772). Severe AIHA contributed neither to damage nor to mortality. CONCLUSIONS: Severe AIHA occurs during the early course of SLE. Male sex and higher disease activity at diagnosis emerged as independent predictors of a shorter time to severe AIHA occurrence. Although not statistically significant, hematological abnormalities at SLE diagnosis could predict the occurrence of severe AIHA in a shorter time. Damage and mortality did not seem to be impacted by the occurrence of severe AIHA.

Inequity and vulnerability in Latin American Indigenous and non-Indigenous populations with rheumatic diseases: a syndemic approach.

Syndemics are a framework that documents health inequities and vulnerabilities in populations with rheumatic diseases. Compared with other approaches, syndemics are able to conjunctly consider epidemiological, biological, sociodemographic and economic factors, and their interactions. OBJECTIVE: To estimate health inequity and vulnerability among Indigenous and non-Indigenous populations with rheumatic and musculoskeletal diseases (RMD) in Latin America using the syndemic approach. DESIGN: This is a secondary analysis of a previously published large-scale study on the prevalence of RMD. SETTING: Studies carried out in five Latin American countries (Argentina, Colombia, Ecuador, Mexico and Venezuela). Health inequity and vulnerability in RMD were identified through a syndemic approach using network and cluster analysis. PARTICIPANTS: A total of 44 560 individuals were studied: 29.78% self-identified as Indigenous, 60.92% were female, the mean age was 43.25 years. Twenty clusters were identified in the Indigenous population and 17 in the non-Indigenous population. RESULTS: The variables associated with RMD among Indigenous populations were rurality, public health system, high joint biomechanical stress, greater pain, disability and alcoholism; and among non-Indigenous people they were being a woman, urban origin, older age, private health system, joint biomechanical stress, greater pain and disability. We identified different health inequities among patients with RMD (ie, lower educational attainment, more comorbidities), associated with factors such as Indigenous self-identification and rural residence. CONCLUSIONS: A syndemic approach enables us to identify health inequities in RMD, as shown by higher prevalence of comorbidities, disability and socioeconomic factors like lower educational attainment. These inequities exist for the overall population of patients with RMD, although it is more evident in Indigenous groups with added layers of vulnerability.

Remission and low disease activity (LDA) prevent damage accrual in patients with systemic lupus erythematosus: results from the Systemic Lupus International Collaborating Clinics (SLICC) inception cohort.

OBJECTIVE: To determine the independent impact of different definitions of remission and low disease activity (LDA) on damage accrual. METHODS: Patients with ≥2 annual assessments from a longitudinal multinational inception lupus cohort were studied. Five mutually exclusive disease activity states were defined: remission off-treatment: clinical Systemic Lupus Erythematosus Disease Activity Index (cSLEDAI)-2K=0, without prednisone or immunosuppressants; remission on-treatment: cSLEDAI-2K score=0, prednisone ≤5 mg/day and/or maintenance immunosuppressants; low disease activity Toronto cohort (LDA-TC): cSLEDAI-2K score of ≤2, without prednisone or immunosuppressants; modified lupus low disease activity (mLLDAS): Systemic Lupus Erythematosus Disease Activity Index-2K score of 4 with no activity in major organ/systems, no new disease activity, prednisone ≤7.5 mg/day and/or maintenance immunosuppressants; active: all remaining visits. Only the most stringent definition was used per visit. Antimalarials were allowed in all. The proportion of time that patients were in a specific state at each visit since cohort entry was determined. Damage accrual was ascertained with the Systemic Lupus International Collaborating Clinics/American College of Rheumatology Damage Index (SDI). Univariable and multivariable generalised estimated equation negative binomial regression models were used. Time-dependent covariates were determined at the same annual visit as the disease activity state but the SDI at the subsequent visit. RESULTS: There were 1652 patients, 1464 (88.6%) female, mean age at diagnosis 34.2 (SD 13.4) years and mean follow-up time of 7.7 (SD 4.8) years. Being in remission off-treatment, remission on-treatment, LDA-TC and mLLDAS (per 25% increase) were each associated with a lower probability of damage accrual (remission off-treatment: incidence rate ratio (IRR)=0.75, 95% CI 0.70 to 0.81; remission on-treatment: IRR=0.68, 95% CI 0.62 to 0.75; LDA: IRR=0.79, 95% CI 0.68 to 0.92; and mLLDAS: IRR=0.76, 95% CI 0.65 to 0.89)). CONCLUSIONS: Remission on-treatment and off-treatment, LDA-TC and mLLDAS were associated with less damage accrual, even adjusting for possible confounders and effect modifiers.

Social networks as education strategies for indigenous patients with rheumatoid arthritis during COVID-19 pandemic. Are they useful?

INTRODUCTION: The use of online education strategies has been introduced as a tool to support health care in patients with rheumatic disease. However, it is important to consider the patient's sociocultural environment. OBJECTIVE: To design and assessment of bilingual audiovisual material acceptability, by means of two social networks, for patients with rheumatoid arthritis (RA) in the qom community in Argentina. METHODS: A qualitative study was performed in two stages: (1) audiovisual material design, development, and validation implementing a collaborative action research method. (2) Publishing of the material on two social networks at two different times. The selected topic was the coronavirus disease 2019 impact on patients with RA. A qualitative and quantitative data analysis was performed. RESULTS: Forty subjects participated into the initial validation stage with a 70% acceptance rate. First, 28 subjects (70%) participated on Facebook and 25 (62.5%) joined the WhatsApp group. Then, the same number of subjects participated on Facebook, while only 45% of subjects participated on WhatsApp. Most of them participated using short phrases such as "I like it." The 60% of the participants played the videos. However, less than 10% shared them. Videos in Spanish were the once most shared. Participation dramatically fell during the second time, and 40% of the WhatsApp subjects never participated. CONCLUSION: The strategies developed for this indigenous community were of no utility, probably because of socio-cultural, economic, and digital barriers. They should be designed and implemented identifying the target group and its environment. Key Points • Online education strategies should be designed with cultural sensitivity. • Technological barriers make digital inequality visible in vulnerable groups. • Educational interventions should have a collaborative design and they should be created together with the communities. • The COVID-19 pandemic has deepened inequalities in the health care and follow-up of patients with rheumatic diseases, especially between most socially and economically disadvantaged groups.

Controversies in Systemic Lupus Erythematosus 2021: Changing the Paradigm in the Management of Lupus Nephritis.

ABSTRACT: Lupus nephritis (LN) affects about a third of patients with systemic lupus erythematosus. Although the use of conventional therapy has significantly improved the prognosis of LN, the response to treatment remains suboptimal, with high rates of relapse and the occurrence of end-stage kidney disease. The implementation of new diagnostic and treatment strategies aimed at improving these outcomes represents a necessary paradigm shift in the management of LN.Herein, we discuss different points of view regarding these still unresolved issues; these comments represent a debate that took place during the virtual congress of the Pan American League of Associations for Rheumatology (PANLAR) and which was organized by the PANLAR Lupus Study Group, GLADEL (Grupo Latino Americano De Estudio del Lupus) on August 15, 2021.

Global excellence in rheumatology in Latin America: The case of systemic lupus erythematosus.

Systemic lupus erythematosus (SLE) affects more severely non-White populations, due to their genetic background and sociodemographic characteristics. Several studies have evaluated Latin American SLE patients to determine their genetic and clinical characteristics as well as prognostic factors; these studies have not only allowed the development of treatment guidelines aimed at the region but also to support regional and global projects. Additionally, educational activities in Spanish and Portuguese have been started to reduce our patients' health illiteracy. Despite the relatively low research output from Latin American countries, we consider that studies from our region coupled with the networks developed to increase our capabilities, could be a model for other rare autoimmune diseases.

Controversies in Systemic Lupus Erythematosus: Are We Treating Our Patients Adequately?

ABSTRACT: Systemic lupus erythematosus (SLE) is characterized by great clinical heterogeneity. The objectives of its management are to make a timely diagnosis and to initiate treatment as promptly as possible so organ damage can be avoided while at the same time exposure to potentially toxic drugs is minimized so that its overall course and outcome improve. In reviewing the current literature, it became quite clear that there are specific topics in which controversies do exist. These include how to treat patients with incomplete lupus erythematosus, the real possibility of abandoning altogether the use of oral glucocorticoids, and the pros and cons of the use of cyclophosphamide and mycophenolate mofetil for the induction treatment of lupus nephritis. Herein we discuss different points of view regarding these still unresolved issues; these comments represent a debate that took place during the PANLAR Virtual Congress (Pan American League of Associations for Rheumatology) and that was organized by the PANLAR Lupus study group, GLADEL (Grupo Latino Americano De Estudio del Lupus) on September 19, 2020.

Impact of glucocorticoids on the incidence of lupus-related major organ damage: a systematic literature review and meta-regression analysis of longitudinal observational studies.

OBJECTIVE: In systemic lupus erythematosus (SLE), disease activity and glucocorticoid (GC) exposure are known to contribute to irreversible organ damage. We aimed to examine the association between GC exposure and organ damage occurrence. METHODS: We conducted a literature search (PubMed (Medline), Embase and Cochrane January 1966-October 2021). We identified original longitudinal observational studies reporting GC exposure as the proportion of users and/or GC use with dose information as well as the occurrence of new major organ damage as defined in the Systemic Lupus International Collaborating Clinics/American College of Rheumatology Damage Index. Meta-regression analyses were performed. Reviews, case-reports and studies with <5 years of follow-up, <50 patients, different outcomes and special populations were excluded. RESULTS: We selected 49 articles including 16 224 patients, 14 755 (90.9%) female with a mean age and disease duration of 35.1 years and of 37.1 months. The mean follow-up time was 104.9 months. For individual damage items, the average daily GC dose was associated with the occurrence of overall cardiovascular events and with osteoporosis with fractures. A higher average cumulative dose adjusted (or not)/number of follow-up years and a higher proportion of patients on GC were associated with the occurrence of osteonecrosis. CONCLUSIONS: We confirm associations of GC use with three specific damage items. In treating patients with SLE, our aim should be to maximise the efficacy of GC and to minimise their harms.

Accelerated atherosclerosis and cardiovascular disease in systemic lupus erythematosus / Aterosclerosis acelerada y enfermedad cardiovascular en el lupus eritematoso sistémico

ABSTRACT Cardiovascular disease (CVD), particularly coronary heart disease and stroke, is one of the most important causes of morbidity and mortality in patients with systemic lupus erythematosus (SLE). The increased prevalence of CVD and subclinical atherosclerosis, even after adjustment for traditional risk factors, are well established. Several associations with disease-related clinical, genetic and immunological features have been identified. The SLE-specific stratification algorithms with emphasis on composite risk-assessment scores including both traditional risk factors and novel biomarkers is recommended. The clinical complexity of accelerated atherosclerosis will most likely require an integrated approach for the identification, treatment, and intensive study into this aspect of SLE that will ultimately lead to improved cardiovascular outcomes for these patients.

RESUMEN La enfermedad cardiovascular (ECV), en particular la enfermedad coronaria y el ictus, es una de las causas más importantes de morbimortalidad en pacientes con lupus eritematoso sistémico (LES). El aumento en la prevalencia de la ECV y de la aterosclerosis subclínica, aun después del ajuste de los factores de riesgo tradicionales, está claramente establecida. Se han identificado diversas asociaciones con características clínicas, genéticas e inmunológicas relacionadas con la enfermedad. Se recomienda el uso de los algoritmos de estratificación específicos para el LES, con énfasis en los puntajes compuestos de evaluación de riesgo, incluyendo tanto los factores de riesgo tradicionales como los nuevos biomarcadores. La complejidad clínica de la aterosclerosis acelerada muy probablemente requerirá un abordaje integral para la identificación, el tratamiento y el estudio intensivo de este aspecto del LES, que en última instancia permita obtener mejores desenlaces cardiovasculares en estos pacientes.

«Living with rheumatoid arthritis¼ in an indigenous qom population in Argentina. A qualitative study.

INTRODUCTION: Rheumatoid arthritis (RA) is a chronic disease which impacts patients' quality of life. The prevalence of RA in the qom population was 2.4% and represented an aggressive and disabling disease. The study goal was to describe the experience of the indigenous qom community individual suffering from RA, along with their experience with the local health care system in the city of Rosario, Santa Fe, Argentina. METHODS: Qualitative Study using techniques of participant observation and semi-structured interviews; following a guideline developed by a multidisciplinary research group comprising anthropologists, rheumatologists, nurses, and psychologists. A triangulation strategy was implemented for the analysis. RESULTS: A total of 33 interviews were conducted in 29 individuals with RA. The results showed a "normalization" of their symptoms and of their limitations in performing daily tasks. The individuals' relationship with the local health care system was complex and limited in several aspects (e.g. access to health care, continuity of treatment, complexity of medical care pathway and lack of cultural competence). CONCLUSIONS: RA is a disease that has a negative impact on the daily lives of the qom people living in Rosario. Improving the relationship between this population and the local health care system as well as the implementation of multidisciplinary work should be priorities.

Achieving remission or low disease activity is associated with better outcomes in patients with systemic lupus erythematosus: a systematic literature review.

BACKGROUND: Remission and low disease activity (LDA) have been proposed as the treatment goals for patients with systemic lupus erythematosus (SLE). Several definitions for each have been proposed in the literature. OBJECTIVE: To assess the impact of remission/LDA according to various definitions on relevant outcomes in patients with SLE. METHODS: This systematic literature review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses using PubMed (1946-week 2, April 2021), Cochrane library (1985-week 2, week 2, April 2021) and EMBASE (1974-week 2, April 2021). We included longitudinal and cross-sectional studies in patients with SLE reporting the impact of remission and LDA (regardless their definition) on mortality, damage accrual, flares, health-related quality of life and other outcomes (cardiovascular risk, hospitalisation and direct costs). The quality of evidence was evaluated using the Newcastle-Ottawa Scale. RESULTS: We identified 7497 articles; of them, 31 studies met the inclusion criteria and were evaluated. Some articles reported a positive association with survival, although this was not confirmed in all of them. Organ damage accrual was the most frequently reported outcome, and remission and LDA were reported as protective of this outcome (risk measures varying from 0.04 to 0.95 depending on the definition). Similarly, both states were associated with a lower probability of SLE flares, hospitalisations and a better health-related quality of life, in particular the physical domain. CONCLUSION: Remission and LDA are associated with improvement in multiple outcomes in patients with SLE, thus reinforcing their relevance in clinical practice. PROSPERO REGISTRATION NUMBER: CRD42020162724.

Prevalence of musculoskeletal disorders and rheumatic diseases in an Argentinean indigenous Wichi community.

OBJECTIVE: To estimate the prevalence of musculoskeletal disorders (MSK) and rheumatic diseases in an indigenous Wichi population in Argentina. METHODS: This is a cross-sectional, community-based study using the Community-Oriented Program for the Control of Rheumatic Diseases (COPCORD) methodology in ≥ 18-year-old subjects. Validated surveys were conducted by trained interviewers. Subjects with MSK pain (positive cases) were evaluated by internists and rheumatologists for diagnosis and treatment. RESULTS: A total of 648 interviews were performed (90.4% of the census population). Mean age was 37.5 years (SD 14.8), and 379 (58.5%) were female. The mean years of education was 7.0 (SD 3.7); 552 subjects (85.2%) were covered by the public health care system. A total of 216 (33.3%) subjects had MSK pain in the last 7 days. Rheumatic disease prevalence was as follows: mechanical back pain (19.0%), rheumatic regional pain syndrome (5.2%), osteoarthritis (3.2%), rheumatoid arthritis (RA) (3.2%), inflammatory back pain (1.2%), undifferentiated arthritis (0.3%), Sjögren syndrome (0.15%), and fibromyalgia (0.15%). RA patients included 19 (90.5%) women and 9 (42.9%) with RA family history. One hundred percent were seropositive and 66.7% showed radiologic erosions. The mean of Disease Activity Score [DAS-28 (ESR)] at the time of diagnosis was 5.1 (SD 1.5) and the Health Assessment Questionnaire Disability Index (HAQ-DI) was 0.8 (SD 0.4). CONCLUSION: RA prevalence was 3.2%, one of the highest reported using the COPCORD methodology in indigenous and non-indigenous peoples in Latin America, with a high percentage of family cases. Pain and functional capacity were the variables allowing patients' early referral to a specialist. Key Points • The RA prevalence was 3.2%, one of the highest reported using COPCORD methodology in indigenous and non-indigenous peoples in Latin America. • The patients with RA had high percentage of familiar history of RA. • The pain and functional capacity were the variables associated with a diagnosis of any rheumatic disease and should be considered for early referral. • The mean of the delay in the diagnosis was 5.8 years. In this community, the lack of the "migration health" phenomenon may be a social determinant that negatively impacts their health.

Access to healthcare system of indigenous communities with musculoskeletal disorders and rheumatic disease in Chaco, Argentina: a qualitative study.

INTRODUCTION/OBJECTIVES: The objective of this study is to describe the local healthcare system from the perspective of the health professionals, community health workers, and local representatives of the qom community living in the province of Chaco, Argentina. METHODS: A qualitative study, with an ethnographic approach, was carried out using two techniques: non-participant observations and semi-structured interviews. A guide for the interviews was designed and developed by a multidisciplinary group of GLADERPO researchers. The main aspects included were the following: reference into the local healthcare system and accessibility to the system. Andersen's base conceptual model of health service utilization was applied for the analysis and for structuring the results. RESULTS: A total of 21 people were interviewed, twelve women and nine men with an age ranging between 25 and 60 years old. The main findings were different barriers (communication and cultural) between the community and the healthcare system; "navigation" within the health system carried out by the qom community; and migration and bureaucratization of the health system. CONCLUSIONS: These findings should be incorporated into educational strategies to improve access to healthcare system and adherence to medical treatment, establishing an interaction between the different levels of the local care system and providing community health workers with an appropriate training with the support of the community representatives. Key Points • The different barriers between the community and the healthcare system were described. • The "navigation" within the health system carried out by the qom community and the migration were relevant points. • The bureaucratization of the health system and the need to design and implement educational strategies in the future were highlighted.

Clinical features, damage accrual, and survival in patients with familial systemic lupus erythematosus: data from a multi-ethnic, multinational Latin American lupus cohort.

OBJECTIVES: This study aimed to compare the clinical features, damage accrual, and survival of patients with familial and sporadic systemic lupus erythematosus (SLE). METHODS: A multi-ethnic, multinational Latin American SLE cohort was studied. Familial lupus was defined as patients with a first-degree SLE relative; these relatives were interviewed in person or by telephone. Clinical variables, disease activity, damage, and mortality were compared. Odds ratios (OR) and 95% confidence intervals (CI) were estimated. Hazard ratios (HR) were calculated using Cox proportional hazard adjusted for potential confounders for time to damage and mortality. RESULTS: A total of 66 (5.6%) patients had familial lupus, and 1110 (94.4%) had sporadic lupus. Both groups were predominantly female, of comparable age, and of similar ethnic distribution. Discoid lupus (OR = 1.97; 95% CI 1.08-3.60) and neurologic disorder (OR = 1.65; 95% CI 1.00-2.73) were significantly associated with familial SLE; pericarditis was negatively associated (OR = 0.35; 95% CI 0.14-0.87). The SLE Disease Activity Index and Systemic Lupus International Collaborating Clinics/American College of Rheumatology Damage Index (SDI) were similar in both groups, although the neuropsychiatric (45.4% vs. 33.5%; p = 0.04) and musculoskeletal (6.1% vs. 1.9%; p = 0.02) domains of the SDI were more frequent in familial lupus. They were not retained in the Cox models (by domains). Familial lupus was not significantly associated with damage accrual (HR = 0.69; 95% CI 0.30-1.55) or mortality (HR = 1.23; 95% CI 0.26-4.81). CONCLUSION: Familial SLE is not characterized by a more severe form of disease than sporadic lupus. We also observed that familial SLE has a higher frequency of discoid lupus and neurologic manifestations and a lower frequency of pericarditis.

«Living with Rheumatoid Arthritis¼ in an Indigenous Qom Population in Argentina. A Qualitative Study. / «Vivir con artritis reumatoide¼ en una población indígena qom en la Argentina. Un estudio cualitativo.

INTRODUCTION: Rheumatoid arthritis (RA) is a chronic disease which impacts patients' quality of life. The prevalence of RA in the qom population was 2.4% and represented an aggressive and disabling disease. The study goal was to describe the experience of the indigenous qom community individual suffering from RA, along with their experience with the local health care system in the city of Rosario, Santa Fe, Argentina. METHODS: Qualitative Study using techniques of participant observation and semi-structured interviews; following a guideline developed by a multidisciplinary research group comprising anthropologists, rheumatologists, nurses, and psychologists. A triangulation strategy was implemented for the analysis. RESULTS: A total of 33 interviews were conducted in 29 individuals with RA. The results showed a «normalization¼ of their symptoms and of their limitations in performing daily tasks. The individual relationships with the local health care system was complex and limited in several aspects (e.g. access to health care, continuity of treatment, complexity of medical care pathway and lack of cultural competence). CONCLUSIONS: RA is a disease that has a negative impact on the daily lives of the qom people living in Rosario. Improving the relationship between this population and the local health care system as well as the implementation of multidisciplinary work should be priorities.

Syndemic and syndemogenesis of low back pain in Latin-American population: a network and cluster analysis.

INTRODUCTION: Although low back pain (LBP) is a high-impact health condition, its burden has not been examined from the syndemic perspective. OBJECTIVE: To compare and assess clinical, socioeconomic, and geographic factors associated with LBP prevalence in low-income and upper-middle-income countries using syndemic and syndemogenesis frameworks based on network and cluster analyses. METHODS: Analyses were performed by adopting network and cluster design, whereby interrelations among the individual and social variables and their combinations were established. The required data was sourced from the databases pertaining to the six Latin-American countries. RESULTS: Database searches yielded a sample of 55,724 individuals (mean age 43.38 years, SD = 17.93), 24.12% of whom were indigenous, and 60.61% were women. The diagnosed with LBP comprised 6.59% of the total population. Network analysis showed higher relationship individuals' variables such as comorbidities, unhealthy habits, low educational level, living in rural areas, and indigenous status were found to be significantly associated with LBP. Cluster analysis showed significant association between LBP prevalence and social variables (e.g. Gender inequality Index, Human Development Index, Income Inequality). CONCLUSIONS: LBP is a highly prevalent condition in Latin-American populations with a high impact on the quality of life of young adults. It is particularly debilitating for women, indigenous individuals, and those with low educational level, and is further exacerbated by the presence of comorbidities, especially those in the mental health domain. Thus, the study findings demonstrate that syndemic and syndemogenesis have the potential to widen the health inequities stemming from LBP in vulnerable populations. Key points • Syndemic and syndemogenesis evidence health disparities in Latin-American populations, documenting the complexity of suffering from a disease such as low back pain that is associated with comorbidities, unhealthy habits, and the social and regional context where they live. • The use of network and cluster analyses are useful tools for documenting the complexity and the multifaceted impact in health in large populations as well as the differences between countries. • The variability and impact of socioeconomic indicators (e.g., Gini index) related to low back pain and comorbidities could be felt through the use of cluster analysis, which generates evidence of regional inequality in Latin America. • Populations can be studied from different models (network and cluster analysis) and grouping, presenting new interpretations beyond geographical groupings, such as syndemic and inequity in health.

Applying the 2019 EULAR/ACR lupus criteria to patients from an established cohort: a Latin American perspective.

OBJECTIVE: To evaluate the performance of the 2019 European League Against Rheumatism (EULAR)/American College of Rheumatology (ACR) systemic lupus erythematosus (SLE) criteria in terms of earlier patients' classification in comparison to the 1982/1997 ACR or the 2012 Systemic Lupus International Collaborating Clinics (SLICC) criteria. MATERIALS AND METHODS: Patients from a Latin America, multiethnic, multicentre cohort, where SLE was defined using the physicians' diagnosis, were included. To calculate the sensitivity of the 2019 EULAR/ACR criteria, the 1982/1997 ACR criteria were considered the gold standard. Additionally, comparison of the 1982/1997 ACR criteria and the 2012 SLICC criteria with the 2019 EULAR/ACR criteria was performed. RESULTS: The sensitivity of the 2019 EULAR/ACR criteria when compared with the 1982/1997 ACR criteria as the gold standard was 91.3%. This new set of criteria allowed an earlier SLE patient classification in 7.4% (mean 0.67 years) and 0.6% (mean 1.47 years) than the 1982/1997 ACR and the 2012 SLICC criteria, respectively. Patients accruing the 2019 EULAR/ACR earlier than the 1982/1997 ACR criteria were more likely to have high anti-dsDNA titres; those accruing them later were less likely to have mucocutaneous and joint manifestations; this was not observed when comparing them with the 2012 SLICC criteria. CONCLUSIONS: The 2019 EULAR/ACR criteria classified earlier only a small proportion of Latin America patients than with the two other criteria sets in real-life clinical practice scenarios. Further studies in different patient populations are needed before these new criteria are adopted worldwide.