PROBABILITY OF HOSPITALIZATION AND DEATH AMONG COVID-19 PATIENTS WITH COMORBIDITY DURING OUTBREAKS OCCURRING IN MEXICO CITY
Authors: Sifuentes-Osornio José , Angulo-Guerrero Ofelia , De-Anda-Jáuregui Guillermo , Díaz-De-León-Santiago Juan L. , Hernández-Lemus Enrique , Benítez-Pérez Héctor , Herrera Luis A. , López-Arellano Oliva , Revuelta-Herrera Arturo , Rosales-Tapia Ana R. , Ruiz-Gutiérrez Rosaura , Suárez-Lastra Manuel , Sheinbaum-Pardo Claudia , Kershenobich David 
Published: December 2021

Background

Worldwide, it has been observed that there is a strong association between the severity of COVID-19 and with being over 40 years of age, having diabetes mellitus (DM), hypertension and/or obesity.

Objective

To compare the probability of death caused by COVID-19 in patients with comorbidities during three periods defined for this study as follows: first wave (March 23 to July 12, 2020), interwave period (July 13 to October 25, 2020), and the second wave (October 26, 2020, to March 29, 2021) using the different fatality rates observed in Mexico City.

Methods

The cohort studied included individuals over 20 years of age. During the first wave (symptomatic), the interwave period, and the second wave (symptomatic and asymptomatic), participants were diagnosed using nasopharyngeal swabs taken in kiosks. Symptomatic individuals with risk factors for serious disease or death were referred to hospital. SARS-CoV-2 infection was defined by real time polymerase chain reaction in all hospitalized patients. All data from hospitalized patients and outpatients were added to the SISVER database.

Results

The total cohort size for this study was 2,260,156 persons (having a mean age of 43.1 years). Of these, 8.6% suffered from DM, 11.6% from hypertension, and 9.7% from obesity. Of the total of 2,260,156 persons, 666,694 tested positive (29.5%) to SARS CoV-2, (with a mean age of 45). During the first wave, 82,489 tested positive; in the interwave period, 112,115; and during the second wave, 472,090. That is, a considerable increase in the number of cases of infection was observed in all age groups between the first and second waves (an increase of +472% on the first wave).

Of the infected persons, a total of 85,587 (12.8%) were hospitalized: 24,023 in the first wave (29.1% of those who tested positive in this period); 16,935 (15.1%) during the interwave period, and 44,629 (9.5%) in the second wave, which represents an increase of 85.77% on the first wave.

Of the hospitalized patients, there were 42,979 deaths (50.2% of those hospitalized), in the first wave, 11,964 (49.8% of those hospitalized in this period), during the interwave period, 6,794 (40.1%), and in the second wave 24,221 (54.3%), an increase of +102.4% between the first wave and the second.

While within the general population, the probability of a patient dying having both COVID-19 and one of the specified comorbidities (DM, obesity, or arterial hypertension) showed a systematic reduction across all age groups, the probability of death for a hospitalized patient with comorbidities increased across all age groups during the second wave. When comparing the fatality rate of hospitalized COVID-19 patients in the second wave with those of the first wave and the interwave period, a significant increase was observed across all age groups, even in individuals without comorbidities.

Conclusion

The data from this study show a considerable increase in the number of detected cases of infection in all age groups between the first and second waves. In addition, 12.8% of those infected were hospitalized for severe COVID-19, representing an increase of +85.9% from the first wave to the second. A high mortality rate was observed among hospitalized patients (>50%), as was a higher probability of death in hospitalized COVID-19 patients with comorbidities for all age groups during the second wave, although there had been a slight decrease during the interwave period.

SUMMARY BOX

What is already known?

Worldwide the resurging of COVID-19 cases in waves has been observed. In Mexico, like in the rest of the world, we have observed surges of SARS CoV-2 infections, COVID-19 hospitalizations and fatal outcomes followed by decreases leading to local minima. Pre-existing health conditions such as being older, having diabetes mellitus (DM), hypertension and/or obesity has been observed to be associated with an increase in the severity of COVID-19.

What are the new findings?

Between the first and second waves, considerable increases were observed in the number of detected cases of infection (+472%), in the number of hospitalized subjects (+85.9%), and the number of hospitalized subjects and deaths (+102.4%) in all age groups.

When analysing only hospitalized individuals, with or without comorbidities, the Case Fatality Rate was high (50.2%), the probability of death increased considerably in all age groups between the first and second waves. This increase was more noticeable in those individuals with previously identified comorbidities (DM, hypertension, or obesity).

An increased probability of death among individuals without comorbidities was observed between the first and second waves.

What do the new findings imply?

During the second wave, demand for hospitalization increased, magnifying the impact of age and comorbidities as risk factors. This situation highlights the importance of decreasing the prevalence of comorbidities among the population.