This study is the first Colombian report on the experience in a tertiary hospital during the first year of the COVID-19 pandemic, describing a decrease in the overall mortality associated with changes in epidemiological, clinical, and hospital characteristics across the time. We found more patients, predominantly men, with a higher frequency of emergency room allocation and higher mortality rate in the first period. On the other hand, we identified an increased disease awareness level in the second period, with a greater positivity rate in the RT-PCR result and higher hospitalization rates in the general ward. In addition, we found that age had a significant impact on mortality, with the likelihood of dying being 3.5 and 8.5 times higher among those between 61-80 and 81-99 years of age, respectively. According to published literature, age is associated with mortality in both periods, in line with the reports in other viral infections(8)(9)(10).
Mortality from COVID-19 is variable in the literature(11)(12). Such variability has been attributed to geographical differences in the prevalence of comorbidities and the severity of the disease. Thus, the highest mortality rate has been reported in Latin America and Europe, where, in addition, older age and more comorbidities have been reported(13).
In this publication, as in the literature, the probability of ICU admission also increased with age. Recent reports suggest that approximately 14%-29% of hospitalized patients with COVID-19 pneumonia require intensive care. In these reports, the patients were older, predominantly male, and had underlying comorbidities(14).
An aspect that contributed to a more comprehensive, timely, and adequate management of patients was the improved performance of diagnostic tests. The rate of positive RT-PCR was higher in the second period. This change might be explained by three factors that improved molecular test performance compared to the first period—first, the inclusion of the Berlin protocol with better sensitivity(15)(16). Second, we optimized the “right time” in the disease course to perform the RT-PCR test and decreased false negatives. Finally, a change in the collected specimens, from the nasopharyngeal swab to tracheal aspiration, and bronchoalveolar washing, with higher sensitivity and/or higher viral load(17).
We also explored disease awareness in our study and observed that, initially, the attitude of the community was different and could impact the time to seek attention. History has shown that fear, discrimination, and stigmatization are frequently observed in a pandemic, especially in the first moments of disease onset(18). This situation can cause delays in consulting and seeking assistance, and worse outcomes, as was the case in our study. For this reason, it is essential to detect and prevent misinformation while educating and informing the community to obtain favorable results(19)(20)(21).
The epidemic curve ascent, that is, the speed with which the cases occurred during a peak, evaluated by DOP, DOE, DOP/DOE, and SI, could explain the higher mortality rate in the first pandemic period. These epidemiological indicators, proposed in other scenarios, have been little evaluated during the pandemic and could help decision-making(7).
Concomitantly, the relationship between the incidence of COVID-19, the frequency of ICU admissions, and the mortality rate has been raised(12). The entire world was isolated and confined for months trying to prepare ICU beds and ventilators to prevent the pandemic from overwhelming the capacity of health systems. Our study showed higher mortality and hospitalization rates in the emergency room during the first period. In contrast, we had a higher probability of hospitalization in the general ward during the second period, assuming a better patient allocation, with no differences in ICU admission between the periods.
The most important finding in our study was a progressive and significant decrease in mortality, with a lower risk of mortality for patients after week 35. The need for emergency beds, general hospitalization, and intensive care vary with the dynamics of the pandemic, and their availability must also change. The ability to overcome these issues possibly affects clinical outcomes. An improvement in identifying and allocating patients according to severity using early warning systems and institutional response teams may optimize the available resources. These changes can facilitate an institution to face the pandemic, impacting clinical outcomes(12).
The limitations of this study should be acknowledged. The retrospective single-center cohort analysis can make it difficult to generalize results in a broader context. However, the follow-up period of one year, the inclusion of two periods, and similarities in characteristics with those of other Latin American regions may help interpret this finding in a global context. Additionally, multicenter studies comparing institutional changes, differences, and similarities are needed to understand the shift in mortality during the COVID-19 pandemic.
Although it is impossible to rule out the changes regarding the virus, our results allowed us to suggest, like other studies, that better knowledge, preparation, and availability of resources, both in the community and in the health services, can impact clinical outcomes. In addition, our results can help generate proposals to face the subsequent surges and/or future pandemics.