Waitlist Mortality Rate

The waitlist mortality rate tells how frequently patients listed for a transplant at a program die before undergoing transplant. This metric appears in the search results when you search for transplant programs, in the summary data shown for each program, and in the program's full program-specific report. Start your search for a particular program using the search box at the top of the page.


Why might this metric be important to me?

The waitlist mortality rate is a measure of how frequently patients listed for transplant at a program die before undergoing transplant. Programs with higher waitlist mortality rates tend to have more patients die than programs with lower waitlist mortality rates. When comparing different programs, it may be worth considering which programs have higher or lower waitlist mortality rates. However, differences may be due to variations in the types of patients on the waiting list or simply to random variation, and may not represent meaningful distinctions across programs.

What do the numbers mean?

The waitlist mortality rate tells you the number of patients who died before undergoing transplant for every 100 patients listed at the program during a year. Importantly, this metric is meant to convey mortality once listed rather than while listed. Therefore, removals from the list for reasons other than transplant, recovery of health, or transfer to another program are ignored, and patients are followed after being removed from the list to ascertain whether a death occurred. Patients removed from the list due to recovery or transfer are followed for an additional 60 days. Not every program has 100 patients on its waiting list, and many programs have many more. To make it easier to compare numbers across programs, the rate is given “per 100 patient-years,” which means the rate is normalized for each program to what it would be if the program had 100 patients on its list for a year. For example, a waitlist mortality rate of 12 per 100 patient-years means that for every 100 patients on the list during a year, 12  died before undergoing transplant. Because this is a normalized rate, the number may include a decimal, for example, 12.4 per 100 patient-years. This means that we may expect slightly more than 12 patients to die for every 100 patients on the list during a year.

What does the comparison to the national waitlist mortality rate mean?

To provide context to each program’s waitlist mortality rate, we show the waitlist mortality rate for all patients on the national waiting list. If the program’s waitlist mortality rate is higher or lower than the national waitlist mortality rate, its patients are dying before undergoing transplant at a higher or lower rate than all patients nationally. Differences between the program’s rate and the national rate may be due to differences in the types of patients on a program's waiting list; for example, patients may be sicker than patients nationally, or differences may be due to random variation rather than meaningful distinctions. We provide an assessment of whether the difference is likely statistical noise or a truly higher or lower rate than the national rate after taking into consideration the types of patients on the program’s waiting list.

How is this metric calculated?

The waitlist mortality rate is calculated by considering all patients on the program’s waiting list (or after removal from the list) during a 1-year period. Patients are followed from the start of the year or their listing date, whichever is later, until the earliest of transplant, the end of the observation year, or 60 days after removal from the list due to recovery of health or transfer to another program. We count the number of days that each patient was alive during that period. We then count how many patients died before undergoing transplant. We then divide the number of patients who died by the total number of days patients were alive and standardize this to a rate per 100 patient-years. The following table provides an example of the calculation:

 

Number of patients on the program’s waiting list at any time during the 1-year period:

760

Total number of days patients were alive during the observation period:

207,000

Number of patients who died during the observation period:

70

Mortality rate per one patient-day:

70/207,000 = 0.00033816 deaths per patient per day

Standardized to a rate per 100 patient-years:

70 x 36,525/207,000 = 12.35 deaths per 100 patient-years

What are some things I should think about when interpreting the waitlist mortality rate?

The waitlist mortality rate provides an overall summary of how frequently patients die before undergoing transplant at this program. Many characteristics specific to you may increase or decrease your likelihood of dying before undergoing transplant. Your care team can discuss those specific characteristics and how they may affect your outcome after being listed.

Where can I find more information?

For more information, you can refer to the analytic methods used to construct the program-specific reports, or contact SRTR.

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