Real Numeracy

by George Taniwaki

In a May 2013 post, I described how to generate publicity for your living donor search by getting a local media outlet to provide news coverage. Not every patient will be able to get the editor or producer to do a news story.  If this is your situation, another way to get your message in front of people is to write a letter to the editor of the newspaper.

The letter can be similar to the one described in a Nov 2011 post on sending letters to friends. It should contain the following information:

1. Introduction of patient and matchmaker and why you are sending this letter
2. Short medical history explaining why patient needs a kidney
3. Explanation why matchmaker cannot be donor
4. Request for potential donors to get a blood test (mention that you are especially hopeful of finding a type O donor if patient is type O)
5. Contact info for the living donor transplant coordinator at the transplant hospital where surgery will take place (or the living donor advocate, depending on the process at the transplant hospital).

An example letter is reproduced below. It appeared in the Parkersburg (WV) News and Sentinel May 2013.

I am writing this to get the word out about living kidney donation, possible donors. I am writing this for my husband of 22 years. My husband is very special to me. He has been with me through thick and thin, hard times and happy times. He was a truck driver for 12 years.

He always said he felt like the king of the road when he was in his truck, he truly loved his job. He recently had to give up driving trucks because of a kidney disease. He had this problem for a long time, but his kidney problem steadily declined, making him have to give up driving trucks and be on dialysis. He goes to dialysis three times a week. He seems to be doing OK with the treatments; he tolerates it fine.

He is in need of a kidney transplant. We recently went to Ohio State University to be evaluated for transplantation listing on the national waiting list. His doctors said that he is a good candidate for transplant. The average waiting time for a deceased kidney donor is three to five years.

His best chance to get a kidney sooner is from a living donor. I would like to share some information about this. Kidney donors do not have to be immediate family. They can be anyone. For some people a transplant from a living donor may be their only option. Donors and recipients do not have to be from the same area. There are funds available for travel expenses and lodging. Donors return to a normal life with no fluid restrictions, diet restrictions or physical restrictions. Recipient’s insurance covers donors evaluation, surgery, follow-up care. Your health and life insurance won’t be affected if you donate to someone. For more info about becoming a living donor please contact a living donor coordinator (614) 293-6724 or 1-800-293-8965, option 4.

Let’s pray that someone out there might read this letter and decide to be a living donor. Thats why I wanted to put this letter out for all to read. I hope this will be able to reach many, many people. I need your help in this matter for anyone who has a loved one on dialysis and is in need of a kidney transplant. You might save someone’s life by being a living donor.

Christine Cullum

Parkersburg

For more ideas on finding a donor, see my Kidney patient guide.

by George Taniwaki

Today in Slate Moneybox, Matthew Yglesias strikes down the notion that the decline in U.S. manufacturing jobs has come to an end and the country is experiencing a true manufacturing renaissance.

Recent news stories (e.g., Time Mar 2013) say that the job growth is real, even if it is cyclical rather than structural. But as Mr. Yglesias points out in his blog post, growth of manufacturing jobs over the past four years has barely kept pace with the growth in working age adults.

He also takes the longer view and shows St. Louis Federal Reserve Bank Economic Data (FRED) over the past 90 years, to show that the secular trend of falling manufacturing employment is unlikely to stop. Meanwhile, the importance of service jobs in the economy continues to grow.

Anyway, check out his blog post; it is short and has a very nice analysis.

by George Taniwaki

The American Transplant Congress was held in Seattle (where I live) in May 2013. Unfortunately, I was unable to obtain a press pass. However, I was able to review the abstracts of the papers published in the Amer J Transpl May 2013 (subscription required). Concurrent session 10 was entitled Obesity and Other Comorbid Conditions in Living Kidney Donors. There were six papers in this session. The results were not surprising and the most of them were not positive.

The biggest issue is that the number of Americans who are obese is rising. Obesity is correlated with high blood pressure, coronary heart disease, and Type 2 diabetes. These conditions are all correlated with kidney disease, which has increased dramatically in the U.S. Thus obesity is one of the factors driving an increase in the need for kidney transplants.

Further, overweight and obese patients are more likely to experience complications from surgery. This makes them less likely to become candidates for transplant therapy. On the donor side, obesity makes it harder to be accepted as a donor. With rising obesity in the population, this trend may be exacerbating the shortage of kidney donors.

More donors are less-than-healthy

The first paper in the session (Abstract #69) was entitled “Marked Increase in Pre-Existing Morbidity among Living Kidney Donors in the United States.” The study led by J. Schold at the Cleveland Clinic looked at national data from 1998 to 2010. They discovered a significant rise in comorbidities (presence of diseases unrelated to being a kidney donor) over time. That is, hospitals are accepting more donors who are less healthy than in the past. By 2010 the overall proportion of comorbid conditions was still under 5%, but the trend is troubling.

Figure 1. Obesity, depression, chronic pulmonary disorders, hypertension, and hypothyroidism are all increasing among people accepted as living kidney donors

Rising obesity makes finding donors harder

The next paper (Abstract# 70) is entitled “Obesity Is a Major Barrier to Increasing Living Kidney Donation in the United States.” The study was led by  Zoe Stewart at University of Iowa Hospitals and Clinics, She examined two years of data from a Midwest hospital (presumably the one she works at) to determine the demographic characteristics (age, gender, ethnicity, biological relationship, obesity measured as BMI, marital status, state residency, and education level).

There were a total of 450 potential donors during the two years. The first table shows the actual outcomes of potential donors. Notice that only 12% of potential donors end up actually donating. This reinforces the message that patients should not stop looking for a donor after finding the first one. They must continue the search until the transplant is complete.

*Major reasons for denial included: hypertension (10.2%), BMI>35 (9.6%), renal disease (6.2%), and cardiovascular disease (2.9%).

The second table shows the demographic differences between potential donors that were accepted and transplanted and those who were not. Statistically significant differences are highlighted.

Unfortunately, the table doesn’t shows the demographic differences for each type of potential donor that was not transplanted. Specifically, donors that were not accepted for medical reasons would be more likely to have high BMI than those who didn’t donate because the recipient received a transplant from another donor.

A few differences stick out.

1. White, non-Hispanics are accepted at about twice the rate of African-Americans or Hispanics.
2. Unrelated potential donors are less likely to be accepted than related donors. I speculate this may be because they are more likely to withdraw than related donors.
3. Nondirected donors are accepted at three times the rate of directed donors. This is probably a self-selection bias. Typically, only very healthy individuals would consider becoming a nondirected donor.
4. Out of state potential donors are more likely to be accepted than local ones. I speculate that this is because someone willing to travel to donate is less likely to withdraw.
5. Potential donors with higher education are more likely to be accepted. Perhaps this is because people with higher levels of education are less likely to withdraw. But I speculate that education is a proxy variable for two other factors. Education level is correlated with ethnicity (whites more likely to have gone to college) and with income (which is correlated with better ability to take time off from work and with greater access to healthcare insurance coverage).

Cigarette smoking in donors leads to lower graft survival

A paper (Abstract #71) by S. Waits et al. at the University of Michigan entitled “Cigarette Smoking in Living Kidney Donors and Graft Survival” shows that people who smoke hurt not only their own health but also reduce the graft survival of kidneys they donate. A study of 635 living kidney transplants showed that 26% of donors smoked within the year prior to transplant. A Kaplan-Meier survival analysis estimated that 5 years and 10 years after transplant, patients who received a kidney from a smoker had a 10% higher chance of losing the graft than those who received a kidney from a nonsmoker.

Figure 2. Patients who receive a transplant from a donor who smokes were 10% more likely to lose the graft

It is better to get an older living donor now rather than wait for standard criteria deceased donor

One of the most difficult decisions that kidney patients and their medical staff must make is whether to accept a transplant from an older donor or wait for a younger deceased donor. An analysis (Abstract 72) by R. Sapir-Pichhadze and colleagues at the University of Toronto shows that a 40-year-old dialysis patient receiving a live donor transplant from an 60 year-old living donor can achieve to the same quality adjusted life expectancy (QALE) as waiting for a 30 year-old deceased donor kidney.

The study was conducted using a probabilistic Markov model.

My only comment here is that in theory it would be possible to use a kidney exchange to better match the age of patients and donors. Since there is such a shortage of donor organs, having the older living donor participate in the exchange would increase the total number of transplants performed.

Potential living donors with prediabetic condition are acceptable

Some good news for patients whose potential donor is prediabetic. A study (Abstract 73) by S. Shandran and colleagues at Univ. California San Francisco compared 45 prediabetic donors with 45 normal controls from 1996 to 2007 and found little difference in outcomes. The controls were matched for similar medical characteristics including family history of diabetes.

The mean age of both group of donors at the time of donation was about 47 years. At 30 days after donation both groups had a mean eGFR of about 60 ml/min. The main difference was the mean fasting plasma glucose was 109 mg/dl for the prediabetic group compared to 87 for the controls.

The follow-up study occurred a mean of 10 years after donation. For the original prediabetic group, the mean fasting plasma glucose was now 104.7 mg/dl with only 3 donors (7%) over 125 mg/dl. Only 7 (16%) of the prediabetic donors developed diabetes compared to 1 (2%) of the controls. Their eGFR was 70.7 compared to 67.3 for the controls.

Small donors lead to worse kidney function

The final paper of the session (Abstract 74) looks at the effect of small donor size and donor-to-recipient size mismatch on recipient kidney function. We know that many surgeons reject small donors because they are afraid that poor outcomes will result, but there is very little data on it.

This study was conducted by H. Khamash and colleagues at the Mayo Clinic in Phoenix, Arizona. It was a retrospective study of 579 donor recipient pairs from July 2003 to November 2010, excluding repeat or multiorgan transplants, those with positive crossmatch or presence of DSA, or those with early graft loss or death with functioning graft.

Using an unspecified multivariate analysis, the study found that smaller donor size (defines as body surface area <1.7m^2) older donors (defined as donor more than 10 years older than recipient), and lower donor eGFR (defined as under 40 ml/min) independently associated with lower GFR at one year post living donor kidney transplant. Thus, donor size should continue to be considered a factor when assessing the desirability of a donor for transplant.