(44) Factors associated with the survival of Mexican patients with CF - a Cohort Study.

Background: Cystic fibrosis (CF) is one of the most frequent autosomal diseases in Mexico, with a prevalence estimated at 1:8,500.CF has many factors that can affect survival, including nutritional status, colonization by Pseudomona Aeruginosa and pulmonary function early identification of these factors allows the implementation of therapeutic actions to improve survival and quality of life.

Methods: All patients who attended the CF Clinic were registered, anthropometric evaluation, pulmonary function evaluation with FEV1 and FVC, values more than 80% were considered as optimal lung function, also a social evaluation was performed. Pancreatic exocrine insufficiency was defined as a requirement for regular pancreatic enzyme supplementation, undernutrition was considered BMI -2.0 SD or weight for height - 2.0 SD, treatment government cover was defined as the full supply of pancreatic enzymes, dornase alfa, nebulized tobramycin, salbutamol, vitamins and oral antibiotics as needed. Positive Pseudomona aeruginosa was defined from a sputum sample or cough swab within 7 years old. Data analysis, survival from the date of first assessment to the last visit was calculated by the Kaplan Meier method. Pearson correlation coefficients were calculated to test relationships between predictor variables.

Results: We included 341 patients from 1990 to 2018, the estimated median age of survival is 20 years (95%IC 17.3-23), and 55% of patients were diagnosed before 2 years, with no significant OR for survival. 91% of the patients have pancreatic exocrine insufficiency with a p.value < 0.01 as a predictor variable for survival. 44% of patients had suboptimal values for FEV1 and 26% of our patients had suboptimal values for FVC. Major impacts on survival were detected in patients with positive P.aeuroginosa within 7 years and those with undernutrition. 61% of our patients didn't have treatment government cover with a clear effect on survival. (Figure 1)

Conclusions: To our knowledge, this study is the first report of survival in CF patients in Latin America. It's important to highlight the difference in median survival (MS) reported from USA in 2017 was 43.6 years vs 46.2 in 2019, while the UK MS was 47 years in the same period, which makes a difference of more than 2 decades in the survival reported in our study. The predictor variables affecting survival agree with other reports, but not with the diagnosis before 2 years, this could be explained by 2 reasons, 1) the implementation of CF diagnosis is by newborn screening started in 2015, so, the effect on survival could be not enough yet, 2) those patients with early diagnosis didn't have full treatment coverage. Many interventions have been performed since the beginning of the cohort. We want to highlight the treatment coverage for the government from 2015 and the intervention of the nutrition team (NT) from 2006. The NT was integrated full time into the CF clinic, with the counting of fat grams, dynamic management of pancreatic enzymes, an increase of energy density, a homemade elemental diet, as well as the management of food portions, so we expect to see a greater effect on survival in the following years. However, we want to emphasize that the treatment with CFTR modulators it's not available in Mexico, therefore, the survival results of this study are strongly associated with the multidisciplinary approach and the continuous education of patients and parents, which has made an important difference above all quality of life of patients.

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