The pandemic due to the SARS-CoV-2 coronavirus caused a sudden increase in the requirement for hospital facilities in Chile. This fact has highlighted the critical importance of intensive care units (ICU) to provide the appropriate treatment for each patient. The insufficient knowledge that existed about treatments for this disease in March 2020, when the World Health Organization (WHO) declared a world epidemic, produced a high demand in hospitals as a result of the complex health conditions presented by some of the patients who required the intensive care provided in ICUs hospitals 1. Under the WHO recommendations, countries have adopted various measures to stop the spread of the contagion between people. In Chile, the authorities have established mandatory lockdowns of cities, banning of essential and nonessential businesses, travel restrictions, quarantines, and individual temporary permits to limit population movement within confined areas 2. Despite these restrictions, it has been necessary to significantly increase the number of ICU units available in the country; however, the number of cases arising each day suggests that at some point, the available capacity could be insufficient.
The ICU is a critical unit in the operational planning of a health care facility because it provides life support to critically ill patients. Typically, patients are admitted to the ICU from other units of the hospital care center with different pathologies. As a result of the pandemic, the new influx of patients stresses regular planning. In the daily dynamics of an ICU, and in the absence of a pandemic, a distinction is made between the arrival of scheduled and nonscheduled patients to predict the necessary resources for each period. Scheduled patients require the service at a specific time to perform a specific operation, such as treatments and examinations. Nonscheduled patients suddenly require intensive care, such as injured patients or those with complicated conditions due to a previous operation in a hospital care center. During the pandemic, the influx of patients suddenly increased, stressing decision-making to deal with the available capacity 3–5. During the pandemic, the arrival of patients suddenly increased. As such, knowing the number of patients who would require intensive care would allow for tackling the emergency in the best possible way. Likewise, by knowing in advance the possible point of collapse, the number of additional units needed could be identified by measuring the need for logistical resources 6–9.
To predict the necessary resources needed for an ICU, it is convenient to identify a set of variables with direct influence that allows for obtaining a prediction model. From such variables, it is possible to partially characterize the growth pattern of the pandemic. Alban et al. 10 studied the flow of COVID-19 patients as it relates to scheduled patients, and the difference was observed in patients who presented with the disease because they have uncertain arrival rates. Zhao et al. 11 performed a regression model that predicts the arrival of patients in the ICU. The model considers the existence of previous diseases, demographic data, symptoms, vital signs, and results of medical examinations. Ritter et al. 12 infer the future ICU load from notified infections through a simpler statistical model that considers time lags. In a study by Chowdhury et al. 13, a multivariate prediction model based on clinical and transmission parameters is used to simulate the trajectories of COVID-19 outbreaks in 16 countries and estimate the number of new infections and deaths. Additionally, combining machine learning and epidemiological models allows for a short-term forecast of ICU burden 14. In such a study, the authors considered both the test’s positivity and the number of new infections. In turn, various machine learning models have made it possible to forecast the number of new cases 15. Rees et al. 16 consider the duration of stay of a COVID-19 patient in the ICU as crucial data for decision-making and establish that the average duration is from 4 to 21 days. Hao et al. 17 develop predictive models for disease severity according to the influence of socioeconomic factors and racial equity. In contrast to the main approaches in the literature, we predict the number of COVID-19 ICU beds at the regional level by considering data from PCR tests and measures taken to prevent spread in the region. Each region has several health care centers, and patients can be assigned to any of them.
Different geographical regions of a country present different dynamics of virus spread. The regions of Chile, distributed along a long and narrow country separated by the sea on one side and by the Andes Mountain range on the other side, generate a particular dynamic of disease spread. Determining the most suitable model for each case requires the selection of the appropriate variables and the specification of the model parameters according to the specific availability of resources present in the region. Then, variables such as the number of tests taken, the rate of positivity, and restrictions to mobility adopted are relevant in predicting the ICU burden. In turn, the versatility of the machine learning and forecasting models allows for testing multiple regressors and selecting the most appropriate for each case. A predictive model would allow early estimation of the arrival of patients in the ICU to meet the emergent need for planning and ensure the best use of available resources.
Our current study reveals that an ensemble of forecast models generates lower and upper bounds for the number of COVID-19 ICU beds needed in the future. The models process a set of relevant data recorded during 2020 and 2021 in three regions of Chile. The three regions are representative of the other regions of the country in terms of their population. Specifically, we selected a small population region, an intermediate population region, and the country's largest region. Prediction models are designed with two approaches: the first approach considers time series data on the number of COVID-19 ICU beds used, and the second approach includes feature data that could influence the time series.
Our study consists of the following sections: Section 2 describes the modeling, and Section 3 contains the results. In Section 4, the discussion of the results is presented, and in Section 5, conclusions and future work are detailed.