US researchers develop methods to improve patient screening for compassionate dialysis


Screening protocols to determine who qualifies for ‘compassionate dialysis’ in hospitals with high numbers of uninsured patients are contributing to increased strain on the emergency room (ER), as measured by how long ER patients are waiting to be seen and other metrics. This is according to researchers at Southern Methodist University (SMU) in Dallas, USA, who also propose solutions to the problem in an analysis published online in IISE Transactions on Healthcare Systems Engineering.

It has been estimated that the number of patients needing compassionate dialysis could make up 2–5% of the overall ER population in some public hospitals. Yet, these patients have been ultimately responsible for 20–30% of the total ER visits because of the frequency of their visits—according to an SMU press release, citing previous studies in this space.

“The burden on the ER in these ‘safety-net hospitals’ is so disproportionate, it is naive to focus on relief to the acute dialysis unit alone,” said Sila Çetinkaya (SMU, Dallas, USA). “ER is always a pain point for any hospital.”

Çetinkaya’s research team investigated possible solutions to the problem, including congestion mitigation via modifying the screening threshold, scheduling treated ER patients to come back for more treatment at a set time, and adjusting the screening threshold in response to the available capacity in the dialysis unit at different times of the day.

The issue of compassionate dialysis

The SMU release states that compassionate dialysis is legally required of publicly funded county hospitals in the USA when uninsured patients—including a large number of undocumented immigrants—need, but cannot pay for, dialysis to treat end-stage kidney disease (ESKD), also known as emergent dialysis. But, before providing that dialysis, a skilled nurse and a nephrologist in the ER must evaluate whether that patient has life-threatening conditions, currently based on a series of medical criteria laid out in the hospital’s screening protocol.

County governments set these policies, and hospitals rarely get a say in what the screening protocol rules will be for their emergency room, the release notes. In addition, because it is delivered inconsistently, compassionate dialysis does not sufficiently remove toxins and fluids from the body, and contributes to progressive deterioration in patient health over time. The release goes on to state that, therefore, the odds are very high that these patients will be recurrent arrivals to the ER.

This practice can also be “staggeringly expensive”, with one study conducted by Baylor College of Medicine (Houston, USA) finding that the total cost of care for a year of scheduled dialysis was US$77,000 compared to US$280,000 for emergent dialysis due to ER visits, frequent hospital admissions, and prolonged stays. In light of these existing problems, Çetinkaya said policymakers should use SMU’s high-level analysis to look at several metrics at their safety-net hospital and see if the screening protocol they have put in place is helping or hurting the hospital, and its patients.

The research team quantified the impact of the screening protocol for compassionate dialysis by developing what is known as a stylised queueing model, which was based on patient flow observations and interviews with medical experts at Parkland Memorial Hospital (Dallas, USA). This model allowed SMU to calculate the waiting times, queue length and many other factors for a typical safety-net hospital’s ER, and its acute dialysis unit, if different scenarios took place.

For example, they looked at the impact on overcrowding in both the ER and the dialysis unit if patients seeking dialysis were rejected at a certain rate with the intent of relieving congestion, but then ultimately those patients returned to the ER when they were sicker.

They determined that, if the probability of patients getting rejected from the dialysis unit went from 0.15 to 0.20 when they arrived at the ER, the ER waiting time could increase by 44%. That translates to all ER patients having to wait almost two extra hours to be seen by a doctor. The wait time for the dialysis unit only decreased by 10%, or 24 minutes, in exchange for this burden on the ER. However, the research team also found that there are instances where screening protocols can be useful.

“The key is keeping the number of patients who are rejected for emergent dialysis low and under control,” Çetinkaya said. “Our model gives policymakers a blueprint for how they can use screening protocols effectively, if they are going to have them in place.” A study on their findings regarding the impact these screening protocols currently have is published in Service Science.

Possible solutions

Çetinkaya started to look into the issue in 2016 after she observed the overcrowded waiting room in Parkland’s old ER and was told the reason was partly due to patients needing compassionate dialysis. She worked with Olga Bountali (University of Toronto, Toronto, Canada) and Vishal Ahuja (SMU, Dallas, USA) to create a stylised queueing model for the compassionate dialysis process.

To do this, the SMU research team first established a flowchart for what would happen if a patient was approved to receive emergency dialysis and what would happen if they were denied. This flowchart had four points of interest: the ER, where patients are evaluated based on the screening protocol for dialysis; the dialysis unit; a virtual holding place for patients who were rejected from getting dialysis; and another virtual place for patients who had just completed dialysis treatment.

The team then created a mathematical model and obtained analytical and numerical results to assess how unpredictable, irregular variables affected both the ER and the dialysis unit. They analysed 864 problem instances, looking at variables such as patient revisit patterns, percentage of patients who received treatment, treatment times, and the number of nurses and dialysis machines available.

One potential strategy for improving efficiency at the hospital calls for dialysis patients receiving emergency ER treatment to return to the ER for a follow-up treatment at a specific time, according to the researchers. Since these treated patients would already be identified as in need of emergent dialysis, not having to screen these patients a second time would eliminate a delay in further treatment. They also note that it would lead to reductions in wait times in the ER for all patients.

Collaborating with Çetinkaya and Bountali for this analysis was Farnaz Nourbakhsh (SMU, Dallas, USA), whose simulation model allowed the research team to investigate further possible solutions to the issue. For instance, they found that adjusting the screening protocol for compassionate dialysis patients in response to the number of nurses available in the dialysis unit at three different times of the day resulted in lower ER wait times and less delay for dialysis treatment.


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