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.

Factors associated with treatment of osteoarthritis: Analysis of a COPCORD study in Nuevo León, México

INTRODUCTION

Osteoarthritis (OA) is the most prevalent rheumatic disease in Mexico. Treatment involves pharmacological and non-pharmacological strategies.

OBJECTIVE

To describe the factors associated with treatment of osteoarthritis in the urban and rural population of Nuevo León.

METHODS

Analysis of a cross-sectional study of patients with OA from a COPCORD study database. Univariate and multivariate analyses of the variables associated with treatment of OA.

RESULTS

We included 696 patients with OA with an average age of 58 years (SD 14.1), 484 (69.5%) women. Pain with a visual analog scale (VAS) ≥4 was present in 507 (72.8%) patients. Functional disability was present in 133 (19%) patients and a mean HAQ of 0.37 (IQR 0.75) was found. The most frequent place of OA was knee in 356 (51.1%) patients; 259 (37%) patients already knew their diagnosis. The most employed treatments were non-steroidal anti-inflammatory drugs (289 patients, 58.5%). The variables associated with treatment were age >58 years (OR 1.3, 95% CI 1.0-1.5), female gender (OR 1.17, 95% CI 1.0-1.3), VAS pain ≥4 (OR 1.3, 95% CI 1.1-1.4), functional disability (OR 2.6, 95% CI 1.6-4.1), HAQ >0.375 (OR 1.9, 95% CI 1.5-2.4), and past diagnosis of OA (OR 5.1, 95% CI 3.3-8.0). In the multivariate analysis, VAS pain ≥4 (OR 1.9, 95% CI 1.2-2.8), kneeling disability (OR 3.15, 95% CI 1.3-7.4) and previous diagnosis of OA (OR 7.6, 95% CI 4.5-12.9) had statistical significance.

CONCLUSION

factors associated with treatment of OA are VAS pain ≥4, kneeling disability and previous diagnosis of OA.

Impact of genetic ancestry and sociodemographic status on the clinical expression of systemic lupus erythematosus in American Indian-European populations

OBJECTIVE

American Indian-Europeans, Asians, and African Americans have an excess morbidity from systemic lupus erythematosus (SLE) and a higher prevalence of lupus nephritis than do Caucasians. The aim of this study was to analyze the relationship between genetic ancestry and sociodemographic characteristics and clinical features in a large cohort of American Indian-European SLE patients.

METHODS

A total of 2,116 SLE patients of American Indian-European origin and 4,001 SLE patients of European descent for whom we had clinical data were included in the study. Genotyping of 253 continental ancestry-informative markers was performed on the Illumina platform. Structure and Admixture software were used to determine genetic ancestry proportions of each individual. Logistic regression was used to test the association between genetic ancestry and sociodemographic and clinical characteristics. Odds ratios (ORs) were calculated with 95% confidence intervals (95% CIs).

RESULTS

The average American Indian genetic ancestry of 2,116 SLE patients was 40.7%. American Indian genetic ancestry conferred increased risks of renal involvement (P < 0.0001, OR 3.50 [95% CI 2.63- 4.63]) and early age at onset (P < 0.0001). American Indian ancestry protected against photosensitivity (P < 0.0001, OR 0.58 [95% CI 0.44-0.76]), oral ulcers (P < 0.0001, OR 0.55 [95% CI 0.42-0.72]), and serositis (P < 0.0001, OR 0.56 [95% CI 0.41-0.75]) after adjustment for age, sex, and age at onset. However, age and sex had stronger effects than genetic ancestry on malar rash, discoid rash, arthritis, and neurologic involvement.

CONCLUSION

In general, American Indian genetic ancestry correlates with lower sociodemographic status and increases the risk of developing renal involvement and SLE at an earlier age.

Epidemiology of rheumatic diseases. A community-based study in urban and rural populations in the state of Nuevo Leon, Mexico

OBJECTIVE

To estimate the prevalence of rheumatic diseases in rural and urban populations using the WHO-ILAR COPCORD questionnaire.

METHODS

We conducted a cross-sectional home survey in subjects > 18 years of age in the Mexican state of Nuevo Leon. Results were validated locally against physical examination in positive cases according to an operational definition by 2 rheumatologists. We used a random, balanced, and stratified sample by region of representative subjects.

RESULTS

We surveyed 4713 individuals with a mean age of 43.6 years (SD 17.3); 55.9% were women and 87.1% were from urban areas. Excluding trauma, 1278 individuals (27.1%, 95% CI 25.8%-28.4%) reported musculoskeletal pain in the last 7 days; the prevalence of this variable was almost twice as frequent in women (33% vs 17% in men); 529 (11.2%) had pain associated with trauma. The global prevalence of pain was 38.3%. Mean pain score was 2.4 (SD 3.4) on a pain scale of 0-10. Most subjects classified as positive according to case definition (99%) were evaluated by a rheumatologist. Main diagnoses were osteoarthritis in 17.3% (95% CI 16.2-18.4), back pain in 9.8% (95% CI 9.0-10.7), undifferentiated arthritis in 2.4% (95% CI 2.0-2.9), rheumatoid arthritis in 0.4% (95% CI 0.2-0.6), fibromyalgia in 0.8% (95% CI 0.6-1.1), and gout in 0.3% (95% CI 0.1-0.5).

CONCLUSION

This is the first regional COPCORD study in Mexico performed with a systematic sampling, showing a high prevalence of pain. COPCORD is a useful tool for the early detection of rheumatic diseases as well as for accurately referring patients to different medical care centers and to reduce underreporting of rheumatic diseases.

Prevalence of back pain in the community. A COPCORD-based study in the Mexican population

OBJECTIVE

Back pain (BP) is frequent in the community; its prevalence in México is 6%. Our objective was to determine the prevalence of BP in Mexican communities and determine its most important characteristics.

METHODS

A cross-sectional study of individuals aged > 18 years was conducted in Mexico City and in urban communities in the state of Nuevo León. Sampling in Mexico City was based on community census and in Nuevo León, on stratified, balanced, and random sampling. Procedures included a door-to-door survey, using the Community Oriented Program for the Control of Rheumatic Diseases, to identify individuals with BP > 1 on a visual analog scale in the last 7 days. General practitioners/rheumatology fellows confirmed and characterized BP symptoms.

RESULTS

In all, 8159 individuals (mean age 43.7 yrs, two-thirds female) were surveyed and 1219 had BP. The prevalence of nontraumatic BP in the last 7 days was 8.0% (95% CI 7.5-8.7). The mean age of these individuals was 42.7 years, and 61.9% were female. Thirty-seven percent had inflammatory BP [prevalence of 3.0% (95% CI 2.7-3.4)]. Compared with the state of Nuevo Léon, the characteristics and consequences of BP in Mexico City were more severe. In logistic regression analysis, living in Mexico City, having a paid job, any kind of musculoskeletal pain, high pain intensity, and obesity among other variables were associated with BP.

CONCLUSION

The prevalence of nontraumatic BP in the last 7 days in urban communities in México is 8.0%. However, clinical features and consequences differed among the communities studied, suggesting a role for local factors in BP.