Inpatient Outcomes Associated With Peritoneal Dialysis Versus Hemodialysis Among Adults With End-Stage Kidney Disease: A 2021 National Inpatient Sample Study

When the kidneys fail completely, the body can no longer filter waste and excess fluid from the blood. Without intervention, this condition is fatal. To survive, patients with end-stage kidney disease must rely on a machine or a specialized procedure to take over the work of their organs. The two main ways to do this are hemodialysis and peritoneal dialysis. Hemodialysis is the more common method, where blood is pumped out of the body, cleaned through an external machine, and returned. It usually happens at a clinic several times a week. Peritoneal dialysis works differently; it uses the lining of the patient's own abdomen as a natural filter. A special fluid is introduced into the belly, where it absorbs waste, and then drained out. This method is often done at home, giving patients more flexibility. Both methods keep people alive, but doctors and health systems have long wondered if one approach leads to better results when a patient ends up in the hospital.

A recent study looked at this question by examining a massive collection of hospital records from across the United States. Researchers wanted to see if the type of dialysis a patient used was linked to how well they did during a hospital stay. They focused on adults who were hospitalized and received only one type of dialysis during their admission, either the machine-based kind or the belly-based kind. By comparing thousands of these cases, the team could look at who survived, how long they stayed in the hospital, how much the care cost, and where they went when they were released. The goal was not to prove that one method is strictly better for everyone, but to understand the patterns that appear in real-world hospital data.

The study analyzed data from over 152,000 hospital discharges in 2021, which represented more than 760,000 hospitalizations nationwide. The vast majority of these patients, about 95 percent, were receiving hemodialysis, while the remaining 5 percent were on peritoneal dialysis. Even before adjusting for other factors, the numbers showed a clear difference in outcomes. Patients receiving hemodialysis had a higher rate of death while in the hospital compared to those receiving peritoneal dialysis. Specifically, about 5.7 percent of the hemodialysis group died during their stay, whereas the rate was roughly 3.8 percent for the peritoneal dialysis group.

When the researchers accounted for differences in the patients themselves—such as their age, race, income, and other health conditions like diabetes or heart disease—the pattern held true. Patients treated with peritoneal dialysis were significantly less likely to die in the hospital than those treated with hemodialysis. Beyond survival, the study found that patients on peritoneal dialysis spent less time in the hospital. On average, their stay was shorter by about one and a half days compared to the hemodialysis group. The financial burden of the hospitalization was also lower for the peritoneal dialysis group, with total charges being roughly 22 percent less than those for hemodialysis patients.

Another important finding concerned where patients went after they were well enough to leave. Among those who survived, patients on peritoneal dialysis were more likely to be discharged directly back to their own homes. About 58 percent of these patients went home, compared to roughly 49 percent of the hemodialysis patients. This suggests that patients on peritoneal dialysis might have been in better overall condition or had more support systems in place to manage their care at home.

However, the authors are careful to explain what these numbers do not mean. The study looked at a snapshot of hospital records, not at the long-term lives of patients, and it could not track the same person over multiple visits. The results show a strong association, but they do not prove that switching from one type of dialysis to the other would automatically improve a patient's chances of survival. The people who receive peritoneal dialysis are often different from those who receive hemodialysis before they even get sick. They may be younger, have better functional ability, or have more family support, all of which help them recover faster in the hospital. The data also lacked details on how long patients had been on dialysis or how well their kidneys were working before they failed.

The researchers noted that even after adjusting for known factors like age and other illnesses, the difference in survival rates remained, though it became smaller when they tried to account for how sick the patients were when they arrived. This suggests that there are still hidden differences between the two groups that the hospital records could not capture. For instance, patients on hemodialysis might be more likely to have urgent medical problems or vascular issues that make their hospital stay more complicated. The study also pointed out that the data came from 2021, a time when the healthcare system was still recovering from the pandemic, which might have influenced how patients were treated and discharged.

Ultimately, the study provides a clear picture of what happens in the hospital for these two groups. It shows that, in this specific snapshot of American healthcare, patients admitted for peritoneal dialysis had lower mortality rates, shorter stays, and lower costs than those admitted for hemodialysis. These findings offer reassurance that peritoneal dialysis is not a riskier option during a hospitalization, but they do not offer a simple rule for choosing a treatment. Deciding between these methods depends on many personal factors that go beyond what a hospital database can measure. The real value of this work is in highlighting that while the two methods serve the same life-saving purpose, the journey through a hospital stay looks different for the patients who use them.