Comorbilidad preexistente, el mayor factor de riesgo de mal pronóstico de COVID-19 en la población Mexicana Pre-existing comorbidity, the highest risk factor for poor prognosis of COVID- 19 among the Mexican population

The coronavirus disease 2019 (COVID-19) pandemic represents a challenge for public health and a high risk for patients with pre-existing comorbidity. As of July 20, 2020, the Case Fatality Rate (CFR) was 11.30% and the Mortality Rate (MR) was 31.28 deaths per 100,000 population. In Mexico, the prevalence of obesity, diabetes mellitus, and hypertension among the adult Mexican population is 30%, 9.2%, and 40%, respectively. The objective of this research was to identify the risk factors associated with eight comorbidities and their dependency on age for death caused by COVID-19. Method: This study used the dataset published on July 20, 2020, by the General Directorate of Epidemiology of the Ministry of Health of Mexico. From this dataset, we analysed 130,896 positive COVID-19 cases, where 35,483 (27.107%) patients had one comorbidity, and 95,413 (72.892%) patients had not medical comorbidity. Statistical analyses include the Case Fatality Rate (CFR), the estimation of the Odds Ratio (OR), and its 95% Confidence Interval (CI). Results: The highest CFR was 14.382% for COPD, 10.266% for CKD, 10.126% for diabetes, and 8.954% for hypertension. The obesity CFR was 3.535%. Moreover, we detected a higher risk for patients with COPD, diabetes, and CKD, resulting in OR of 4.443 (95% CI: 3.404-5.799), 3.283 (95% CI: 3.018-3.570), and 3.016 (95% CI: 2.248-4.047), respectively. Calixto Calderón, B. et al. Vol. 13, 2021. Special Issue: COVID-19. ISSN 2007 – 0705 3 Conclusion: This study corroborates that the highest risk for severe disease and death caused by COVID-19 among the Mexican population are pre-existing comorbidities. Findings show that COPD, CKD, diabetes, hypertension, and cardiovascular disease increase the risk of death for patients older than 54 years. The most vulnerable age group is older than 65 years.

From this point, the purpose of this study was to identify the risk factors associated with eight comorbidities and their dependency on age for death caused by COVID-19 among the Mexican population. when the patient died. We created the variable death (yes or no) based on the date of death.

Selection of Variables
It is important to highlight that the prevalence of obesity in Mexico affects over 30% of the adult population (DiBonaventura, et al., 2017), which is strongly associated with cardiovascular disease and type 2 diabetes mellitus. Another relevant data is that Mexico appears in the top ten countries with diabetes mellitus patients. According to (Rojas-Martínez, 2018), the prevalence of diabetes mellitus in Mexico affects over 9.2% of the population. This comorbidity is strongly associated with CKD. Finally, but not less important, hypertension was diagnosed in 40% of the adult population (Campos-Nonato, et al., 2016).

Statistical Analysis of Data
A descriptive analysis of data was performed using Microsoft Excel ®. Discrete variables were examined to identify the risk factor for death between COVID-19 patients with and without comorbidity. Statistical analyses include the CFR, the estimation of the OR, and its 95% CI, using SPSS © (Statistical Package for the Social Sciences) software.

Discussion
The present study provides a more specific analysis of the CFR of eight comorbidities and COVID-19 infection as it did not consider deaths from all causes (combination between two or more comorbidities) among patients during or after COVID-19 treatment. The existence of a national database of suspected cases of COVID-19 (Secretaría de Salud, 2020) allowed identifying the magnitude of each comorbidity and its dependency on age as a risk factor for death among the Mexican population. The results are congruent with previous studies (Carrillo-Vega, 2020), (Parra-Bracamonte, et al., 2020), demonstrating that obesity, hypertension, and diabetes were the comorbidities more prevalent among the Mexican population.
At this time, the increasing number of cases and expansion of COVID-19 in Mexico is causing widespread concern among the population. Despite all the efforts, the number of deaths due to COVID-19 is still considerable, especially among patients with COPD, CKD, diabetes, and hypertension. In New York City, a study had reported risk factors for severe COVID-19 disease in 210 CKD patients, demonstrating that among patients with CKD, severe cases had a higher risk of mortality and intubation (Yamada, et al., 2020) among each age group, requiring more attention from patients and medical units. Patients with obesity between 25 and 64 years have a higher risk of death in our study.
We were surprised to find that asthma has a lower risk of death with an OR 0.447 (95% CI: 0.324-0.617) in the entire group, corroborating previous results (Bousquet, et al., 2020), (Carli, et al., 2020), (Suleyman, et al., 2020). This result has similitude to the cases reported in China, where Pre-existing comorbidity, the highest risk factor for poor prognosis of COVID-19 among the Mexican population Vol. 13, 2021 / Special Issue: COVID-19 / ISSN 2007 -0705 -8 -asthma had not prevalence as a risk factor for mortality (Wang, Pawankar, et al., 2020). As a consequence, it is necessary to further studies on the antiviral and immunomodulatory activities of asthma medications (Johnston, 2020) to take advantage of its benefits in finding a cheap treatment for the Mexican population.
The risk of death from COVID-19 and one comorbidity increased with age, as demonstrated by (Carrillo, et al., 2020), (Parra-Bracamonte, et al., 2020), (Suleyman, et al., 2020), (Thombs, et al., 2007), (Wu & McGoogan, 2020 This study considers official data, which implies assuming different risks or difficulties in interpreting the data contained in the databases. It should be remembered that the complexity that exists with the application, registration, monitoring and control of the pandemic makes it difficult to have a statistical precision than other research could have. In any case, the decision to assess the official data shows important in is against health policies, medical services, and a whole health culture itself than exceeds the scope of this work, but which could be identified.

Conclusion
Our findings also provide a degree of clarity in areas where previous studies have not been in agreement, including the risk factor for mortality among patients with CKD and COPD, and the low risk of death of patients with asthma and COVID-19. It is unclear the future for positive COVID-19 patients, in the following months, in Mexico; however, we can say with certainty that the pre-existing comorbidities among Mexican population represent a high risk of death, which could increase the public health and social expenditures. With this and previous studies, it is clear that the best strategy to reduce deaths is the prevention, in terms of, reduce comorbidities among the Mexican population.