Disparities in cystic fibrosis survival in Mexico: Impact of socioeconomic status

Abstract

Background: Median survival age in cystic fibrosis (CF) has increased in developed countries. Scarce literature exists about survival in Latin America, especially in Mexico. The aim of our study was to assess the median age of survival in CF patients and the impact of risk factors in Mexico over a 20-year period. Methods: We conducted a retrospective study with all patients registered and followed in the CF Center in Monterrey, Mexico from 2000 to 2020. Median survival age was the primary outcome, assessed with Kaplan-Meier analysis. The influence of clinical, biological, and demographic factors on survival was analyzed with Cox regression model. Results: Two-hundred five patients were included. Median survival for the cohort was 21.37 years (95% confidence interval [CI], 17.20-25.55). In the multivariate Cox regression model, low socioeconomic status (hazard ratio [HR], 4.21; 95% CI, 2.43-7.27), chronic Pseudomonas aeruginosa infection at 6 years (HR, 10.45; 95% CI, 5.66-19.28), and pancreatic insufficiency (HR, 3.13; 1.38-7.13) were independent risk factors for mortality. Conclusion:Median survival in Mexican patients with CF is lower than in highincome countries, and socioeconomic status plays a conspicuous role in the disparity. To increase patient survival for those residing in low-middle income countries, public health authorities must design policies that fully cover diagnosis and treatment strategies for the CF population.disparities, low-income countries, median survival age | INTRODUCTIONCystic fibrosis (CF) is a hereditary disease, transmitted in an autosomal recessive manner; its prevalence varies by country, according to ethnic composition. In Mexico, its prevalence is estimated to be approximately 1:8500 to 1:10,000 in live newborns. 1 Survival of those with CF has improved markedly in developed countries, due to early diagnosis, multidisciplinary care, aggressive nutritional supplementation, novel inhaled treatments, eradication of Pseudomonas aeruginosa, and lung transplantation. 2 Despite advances, there is a great deal of variability in disease progression, severity, and survival in different countries and geographic settings. 3,4 There are several factors related to survival, such as the cystic fibrosis transmembrane conductance regulator (CFTR) genotype, 5 initial presentation of the disease, 6 nutritional status, 7 sputum bacteriology, 8,9 diabetes, 10-12 socioeconomic status (SES), 13

Cystic fibrosis‐related mortality trends in Mexico between 1999 and 2020

“…In a previous study carried out by our group, the median age of survival for CF patients followed in a specialized center was 21 years; however, when patients were compared by socioeconomic status, the median age of survival in patients with high socioeconomic level reached 29 years compared to 15 years in the low socioeconomic level. 4 Accordingly, in the current study we observed a lower median age at death in the uninsured population when compared to the cases with medical insurance, which can be a reliable substitute of socioeconomic level.…”

“…3 Previous research by our study group reported a median age at death of 15.5 years during the 2016−2020 period in Mexico. 4 However, in Mexico a national patient registry is currently lacking, therefore the information available is from individual centers and does not cover the entire country's CF population. To contribute to the characterization of CF epidemiology in Mexico, the aim of this study was to analyze the CF-related mortality trends in the Mexican population during a 22-year period (1999−2020) using death certificates data.…”

Trends in cystic fibrosis survival over 40 years in South Africa: An observational cohort study

“…Worldwide, the disparity in CF‐survival between ethnicity is linked to socioeconomic status (SES) and quality of healthcare 12,26 . In a recent study from Mexico, low SES was associated with a fourfold increased risk of mortality with a significantly lower median survival age of 15.1 years in the low SES group compared to 29.4 years in the high SES group 27 . Although SES was not recorded in the SA cohort, ethnicity is a proxy for SES in SA where although being in the minority, average household income in Caucasians is significantly higher than non‐Caucasians 28 .…”

“…12,26 In a recent study from Mexico, low SES was associated with a fourfold increased risk of mortality with a significantly lower median survival age of 15.1 years in the low SES group compared to 29.4 years in the high SES group. 27 Although SES was not recorded in the SA cohort, ethnicity is a proxy for SES in SA where although being in the minority, average household income in Caucasians is significantly higher than non-Caucasians. 28 The higher mortality in non-Caucasian children under 10 years of age observed in this study is a surrogate for SES disparities between ancestries that still exist in SA today as a legacy of Apartheid.…”

A step back in time: The basics of CF care still matter!

“…The healthcare disparities presented by Kaur et al are not unique to India, but also seen in other low‐ and middle‐income countries (LMIC) 7 . Filho et al report similar challenges faced in Brazil, South Africa, and Israel, while Bustamante et al reported disparities in CF‐survival in Mexico 8 …”