An epidemic of delays: Estimating the impact of releasing control measures on the backlog of admission in intensive care units in Switzerland.

Background

A hidden burden of the covid-19 pandemic is the delay of procedures when intensive care units (ICU) need to be cleared in anticipation for epidemic waves. On April 14^th 2021, a number of control measures were lifted in Switzerland, with the potential to increase admissions of COVID-patients in ICUs, and thus limit resources for patients with other conditions. We previously reported on a backlog of an estimated 26,382 patients since the beginning of the covid-19 epidemic in Switzerland (Policy Brief, The double burden of operating near intensive care saturation in Switzerland). Here, following the release of covid-19 control measures we attempt to estimate the additional backlog of patients whose procedures might be delayed because of a 3^rd epidemic wave. This analysis accounts for variations in length of stays in ICU for multiple categories of pathologies as well as the proportion of elective procedures for each of these pathologies. Our estimates are based on yearly reports of ICU occupancy provided by the Swiss Society for Intensive Care Medicine (SGI-SSMI). We thank the SGI-SSMI, for their valuable help, and collaboration. 

Method

We used projections of ICU occupancy for covid-19 patients from Swiss TPH (Prof. Penny et al) for the period April 20^th to September 1^st. Three scenarios were considered with regards to vaccination rates. First, an “optimistic” scenario where vaccination could be scaled-up to 50,000 doses per day immediately. The scenario is called “Medium vaccine rollout, expected relax on April 19”. For comparison, current vaccination rates between April 7^th to April 14^th, were 38,000 doses per day. Therefore, we also considered a second scenario hereafter referred to as “Current vaccination trend”. Projections for this scenario were obtained by averaging projection for ICU occupancy for vaccination rates of 50,000 per day, and 25,000 per day (Penny et al). The third scenario considered was that of very rapid vaccine rollout of 100,000 per day. This scenario would imply multiplying by almost 3 the current pace of vaccination. Projections for ICU occupancy were adjusted such that the first day of projection for April 20^th matches the number of covid-19 ICU patients reported in the IES system on the same date.

The proportion of elective procedures were calculated for each category of diagnostic recognized by the SGI-SSMI using records of all patients that attended ICUs in Switzerland between 2018 and 2020 (n = 165,574). 

Results

In 2019, 82,064 patients were admitted to intensive care in Switzerland, and ICU bed occupancy was 66%. This pre-covid baseline occupancy corresponds to 578 beds in use – averaging over seasonal variations- out of 875 certified ICU beds reported in the IES system (20^th of April 2021). The proportion of patients in ICU for elective procedures was 0.3. The diagnostic associated with the highest proportion of non-urgent elective procedures, and thus likely to be delayed were: R5, Malignant tumor of intra-thoracic organs (74%); R6, Malignant tumor of the respiratory system (72%); M9, Other surgery for metabolic or endocrine diseases, malnutrition, obesity (59%); C9, Other cardiovascular disease such as bypasses, valve, unruptured aortic aneurysms (58%); C5, Aortic Aneurysm (53%), N9, non-urgent neurologic surgery (50%). Patients with urogenital pathologies were removed from the analysis (n<5).