Organs and Overdoses: The Numbers (Part I)

By Brad Segal

The surging opioid epidemic is a threat to the nation’s public health. This year the CDC reported that mortality from drug overdose reached an all-time high, with the annual death toll more than doubling since 2000. Yet in the backdrop of this epidemic, the country also faces ongoing shortages of a different sort–too few organs for transplantation. Every day, approximately 22 people die while waiting for an organ to become available. To some it is not a surprise–or at least not inconceivable–that the fastest-growing source of organ donors is being fueled by the national spike in drug overdoses. This first post will help delineate the scope and scale of the situation. My follow-up will discuss the ethical considerations and ramifications for public policy.

To start: the numbers. The Organ Procurement and Transplantation Network (OPTN) makes domestic transplant data publicly available online, which currently extends from 1994 to September 30th, 2016. Two decades ago, 29 organ donors died from a drug overdose.* In just the first nine months of this year, that number has climbed to 888 donors. Even with a quarter of the calendar year left to be counted, 2016 has already surpassed previous record set in 2015 (Figure 1).

Figure 1

One might question whether this trend is an illusion–perhaps a rise in the incidence of donors who had overdosed reflects an increasing number of transplants. But the data suggest the opposite. Also plotted in Figure 1, the percentage of total organ donors who died from overdose (maroon diamonds, right-sided Y axis) has not remained constant–instead, the percentage has steadily increased. Two decades ago, overdose caused the deaths of 0.6% of all organ donors; this year, it is the cause of death among 12.0% of organ donors nationwide. The rising percentage means that not only are more victims of drug overdose donating organs, but that the pool of organ donors is increasingly composed of such individuals.

Figure 2
Figure 2

Each deceased organ donor can donate multiple vital organs; hence the total number of transplant recipients is greater the number of deceased donors. So far this year, 2790 successful transplants were performed from the 888 donors who died following overdose, or on average 3.1 transplants per individual donor (Figure 2). This rate remains unchanged compared to the overdose-related donors in 1994. While drug use could theoretically impair the viability of a donor’s organs, the rate of organs given by each donor is virtually the same as that among deceased donors of all types in 2016. The key points here: each donor who died by drug overdose is providing around three people with vital organs, that this is unchanged over time, and that this is not greatly different from donors who died by other causes.

Demographic data from the first nine months of 2016 show that 60% of donors who overdosed were between the ages of 18 and 34, which is more than double the 27% donors of the same age range who died from non-drug related causes. Within the 18 to 34 age group, overdose is the second most common reason for death, second only to trauma. While one in three donors who did not die from an overdose are >50 years old, among individuals who overdosed, this age group accounts for less than one in ten donors (36.6% vs. 7.9%). Donors who overdosed are also more likely to be male (61%), which is greater than the proportion of males among donors with a non-drug related cause of death (53%). By donor ethnicity, 83% of individuals who died from an overdose are white, 6% are black, 8% Hispanic, and 1% Asian; among individuals with a non-drug related cause of death, donors are 65% white, 17% black, 14% Hispanic, and 3% Asian. In sum, donors who overdosed are much more likely to be young, slightly more likely to be male, and more likely to be white as compared to donors who did not die from drug overdose.

Finally, I wanted to take a closer look at Massachusetts given that the state has some of the nation’s longest wait-periods for organ transplantation, and has concurrently been hit especially hard by the nationwide drug epidemic.

Figure 3

The Commonwealth’s data are shown in Figure 3. In the first nine months of 2016, Massachusetts reported that 71 of its donors had died from drug overdose, already exceeding the 53 donors last year. Right now in Massachusetts, overdose-related deaths account for over a quarter of total organ donors—a rate well above the national average. Nationally, Massachusetts has the same number of donors who died from overdose in 2016 as New York, and the only other state with a higher number is Pennsylvania, which reports 100 of such donors. But this seems odd—the population of Massachusetts is about half that of Pennsylvania, and it’s only one third the population of New York. The CDC’s data on each state’s drug-overdoses per capita do not fully account for the variability in rates of donation either.

This led me to wonder–has every state undergone the same proportional increase in transplantations from victims of drug overdose relative to that state’s rise in morality from drug overdose? Some states perform too few transplants per year to discern an annual trend. But combining state-level data according to the 11 geographic regions (defined for purposes of organ allocation) allows for a side-by-side comparison of; (1) the CDC’s data on the percent change in deaths from drug overdose between 2013 and 2014 for each region, and; (2) OPTN’s data on the change in number of organ donors who had died from drug intoxication between the same years within the same regions.

Figure 4

As shown in Figure 4, the comparison reveals marked variation. Region 1 (which includes Massachusetts) stands out not only for the sharpest rise in the rate of donors who died from overdose, but also for an increase in annual mortality from drug overdose. The proportion between these two metrics, though, was not the same in other regions. In Region 4 the increase in donors following overdose was disproportionately higher than the rise in mortality. Interestingly, three regions performed fewer transplants from donors who died from an overdose despite an overall increase in the number of overdose-related deaths during the same time period.

A few important limitations to Figure 4 should be noted. In particular, the results only convey the change between two years (2013 – 2014). Second, the record-high numbers of donors who died from overdose were published by OPTN this year and last year, but these years are not shown in the figure because the CDC’s most recent data available is from 2014. Finally, variation in the baseline numbers of both transplants and overdose-related deaths could have affected the significance of the changes between years for the smaller regions in particular. Yet with all of this in mind, the data suggest that different regions of the country greatly vary in terms of how rising rates of drug overdoses have affected organ availability.

My next post on the topic will explore the ethics behind these numbers, and the implications for public policy.

* This oversimplifies for clarity. First, The terminology used in the OPTN dataset define the “cause of death” in a more proximal sense than its common usage. For instance, they might list “anoxia”–lack of oxygen–or “head trauma,” as the cause of death, though both can result from many conditions, and certain conditions can result in either one. Rather than the OPTN’s terminology, which classifies an overdose as a “mechanism of death,” here I opt for the common understanding of “cause of death” whereby death would not have occurred in the absence of drug overdose. Second, it should be noted that the data on donors who died from drug overdose is taken from the OPTN subcategory of “drug intoxication” which includes all cases of drug overdose regardless of the circumstances. The OPTN’s “circumstances of death” explain the context and intent (e.g., suicide, motor vehicle accident, etc). The share of donors who committed suicide by drug overdose has decreased over time, dropping from 58% of donor deaths in 1994 to 11% in 2016. This indicates that the trend in organ donation described is not a result of more individuals intentionally overdosing.

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