Swiss study reviews hospital bed occupancy and mortality risks

The University of Basel study from late 2022 found that mortality rates increased by 2% a day once a certain occupancy threshold had been exceeded. Keystone / Gaetan Bally

When bed occupancy rises, so too does the mortality rate, and sometimes even before the hospital has reached full capacity, a recent Swiss study has found. This is particularly true of smaller facilities.

Throughout the Covid-19 pandemic, the occupancy rate in intensive care units – and hospitals in general – was an issue of burning concern. Yet as long as there are beds available, surely patients can still receive proper care. But is this really true?

To answer this question, the University of Basel investigated the causal relationship between bed occupancy and patient mortality rates. The researchers analysed data from more than 1.1 million inpatient cases at 102 Swiss hospitals. The studExternal linky, which was published in late 2022, found that mortality increased by about 2% a day once a certain occupancy threshold had been exceeded.

“In some cases, mortality increases significantly before the facility has reached full capacity,” Michael Simon, lead researcher and a professor at the Institute of Nursing Sciences at the University of Basel, told SWI swissinfo.ch.

Less fluctuation in larger hospitals

The critical occupancy threshold, above which the mortality risk increases, varies from one hospital to the next, and can range from 42.1% to 95.9% of maximum capacity, the study found.

One determining factor is the size of the hospital, Simon explains. Small facilities, which have an average occupancy rate of 60%, have a lower critical threshold and reach it faster than larger structures, whose average occupancy rate is 90%.

This is because the number of patients tends to fluctuate more in smaller hospitals. For instance, a ten-bed clinic that cares for an average of six patients over the year has a 60% occupancy rate. This means that some days there may be two patients and other days ten, a situation that is difficult to manage, according to Simon. Meanwhile, in larger facilities, such as university hospitals, there is less variation.

From the patient’s point of view, then, is it better to be in a larger hospital? Not necessarily, says the professor. “As a general rule, facilities with a higher, and therefore more constant, occupancy rate are probably the best option for patients,” Simon explains. “These can also include small and medium-sized hospitals.”

The relationship between bed occupancy and hospital mortality rate is complex, he adds. In addition to the proportion of occupied beds, other factors must be taken into account, such as the average severity of the illness and the reason for hospitalisation, as well as the patient’s individual risk of dying, their age and their gender.

Why do people die in hospitals?

Once the critical occupancy threshold of a hospital has been exceeded, there is a risk that diagnoses or treatments will not be performed, or at least not on time, says Simon. Despite strong fluctuations in patient levels, the number of doctors and nurses remains relatively stable.

The Swiss Nurses’ Association (ASI) has for years denounced excessive workloads and a chronic shortage of nursing staff in hospitals. The profession has become increasingly less attractive, with around one-third of nursing graduates now quitting the sector after just a few years of work, according to ASI president Sophie Ley. This exodus was exacerbated by the Covid-19 pandemic, leading to a potential drop in the quality of care provided and a greater risk of complications or premature death.

Statistically, around 2.3% of admitted patients in Switzerland die during their hospital stay, according to Simon. Considering that around one million people are hospitalised each year, the number of deaths can be estimated at about 23,000.

“In most cases, patients die because their time has come,” he says. “Nobody can save them, for instance after a serious car accident or because of a grave illness.”

Meanwhile, deaths caused by medical error range between 2,000 and 3,000 a year, according to estimates by the Federal Office of Public Health.

The University of Basel study on bed occupancy and hospital mortality is the first of its kind and was possible, according to Simon, because all of this patient data is available in Switzerland, unlike in other countries, such as Germany. The conclusions could nonetheless also apply to other national healthcare systems, he believes.

Switzerland is the European country with the highest number of nurses per capitaExternal link (18 per 1,000 inhabitants in 2019). As for the number of available beds compared to the population and the hospital occupancy rate, however, Switzerland’s performance is average or just above that, as the following two graphs show:

Ways to reduce mortality

The problem of increased mortality can be addressed by reducing fluctuations in patient numbers and ensuring that hospitals are properly staffed, Simon believes.

“Health policies need to start [looking at] ways to reduce volatility and to make the healthcare system more resilient,” he says.

In his view, solutions could include closer cooperation between hospitals, better hospital planning and the clustering of smaller clinics. This would not only help to prevent over-occupancy in hospitals, but also to avoid situations where there are too many free beds, leading to a waste of resources.

“Ideally, it would be better to have a few beds with enough nursing staff than a structure with many beds but not enough staff,” the professor concludes.

Translated from Italian by Julia Bassam/gw

How can the healthcare system be improved?

More coordination and more effective use of human and material resources: these are the recommendations to come out of the “Smarter Health Care” National Research Programme (NRP 74), which recently wrapped up five years of research into caring for the chronically ill in Switzerland.

The healthcare sector faces major challenges, not least the growing incidence of chronic diseases and cost pressures, all in an ageing society. “In the coming years, we will need to bring care even more closely in line with the needs of people with chronic diseases,” explains Milo Puhan, president of the NRP 74 steering committee.

According to the findings of the NRP, achieving this goal will require better cooperation among the many professionals involved in care. Coordination is often difficult in a decentralised system like Switzerland’s, the researcher points out.

One project the NPR 74 looked at was focused on planning the discharge of elderly vulnerable patients from hospital, using an online tool that connects doctors, nurses and social workers. Thanks to this, patients could be sent home earlier, without the increased readmission to hospital that is so often the case with this group of people.

Source: Keystone-SDA