Variations in Duration of Kidney Transplant Donor Evaluation

Among patients with kidney failure, kidney transplantation is associated with improved survival, better quality of life, and reduced healthcare costs compared with dialysis therapy. Living donor transplantation provides advantages over deceased donor transplantation, including superior rates of graft and patient survival and shorter time to transplantation.

When potential living donors contact a transplantation center, the evaluation process begins with a series of screening tests, diagnostic tests, and consultations with specialists. The process may require multiple trips to the clinic and frequent periods of waiting for appointments and test results. Efficient living donor evaluation is completed in a timely manner, is clinically appropriate, and results in patients and provider satisfaction.

The 2017 Kidney Disease: Improving Global Outcomes guideline on the evaluation of living donor candidates recommends that donor evaluation be as efficient as possible, and a 2020 United Kingdom goal is for donors to complete the evaluation process within 4.5 months where appropriate.

To date, there are few data available on the time to complete the living donor evaluation. Steven Habbous, MSc, and colleagues on behalf of the Donor Nephrectomy Outcomes Research Network, conducted an analysis of data from one prospective and one retrospective cohort study to examine the time to complete the donor evaluation process, and to assess the variability in times to complete the evaluation between transplantation centers. The researchers also sought to identify the individual and transplantation center factors associated with longer evaluation times. Results were reported in the American Journal of Kidney Diseases [2018;74(4):483-498].

The prospective cohort enrolled donors from 16 centers in Canada and Australia who donated a kidney between September 2009 and January 2015. The current analysis included 849 of 851 donors (two donated outside of Canada or Australia). The included donors were recruited for the study a median of 2.3 weeks prior to donation. The retrospective cohort included 1109 of 1140 living donors from Ontario, Canada.

In the prospective cohort, mean age at donation was 47.8 years, 78% were married, 88% were white, 66% were women, 68% had a college or university degree, 64% were employed full time, and 26% resided in the highest neighborhood-income quintile. Eighty-seven percent of the donors in the prospective cohort underwent laparoscopic nephrectomy and 11% donated through kidney paired donation. In terms of indicators in health status, 18% were classified as obese (body mass index [BMI] ≥30 kg/m2), 2% were classified as very obese (BMI ≥35 kg/m2), and 64% had a predonation estimated glomerular filtration rate ≥90 mL/min/1.73 m2. Nearly half of the donors (48%) were first-degree relative and 8% were nondirected (anonymous).

Some demographic characteristics of donors in the retrospective cohort were similar to those in the prospective cohort: mean age, 45.1 years, 63% women, 84% resided in an urban area, 23% in the highest neighborhood-income quintile, and 50% were first-degree relative of the recipient. However, donors were more likely to be nonwhite (23%) than donors in the Ontario prospective cohort.

Recipients in the retrospective cohort were similar to donors in age, race, rural status, and neighborhood-income quintile, but were more likely to be men (64% vs 37%). Recipients were referred to a transplantation center a median of 26 days following the start of the donor’s evaluation (recipient referral date was available for 290 of 1256 recipients).

In the prospective cohort, median total evaluation time was 10.3 months (n=803); mean total evaluation time varied across transplant centers (intracluster correlation coefficient [ICC], 7.0%; P=.04). In the subgroup of Ontario participants, median evaluation time was 10.7 months, which was similar to the evaluation time in the retrospective cohort (median, 10.8 months).

Median time to approval in the prospective cohort was 7.9 months (n=745; ICC, 13.2%; P=.02); time from approval to donation was 0.7 months (n=745; ICC, 20.6%, P=.01). Data on approval dates were not available for the retrospective cohort.

Among donors in the prospective cohort who completed nephrology, surgery, and psychosocial assessments, median time between the first and last consultation was 3.0 months (n=716; ICC, 11.0%; P=.03). In the retrospective cohort, median time between consults was 3.3 months longer (median 6.3 months [n=576]). Time from computed tomography until donation was a median of 4.8 months in the prospective cohort (n=839; ICC, 2.9%; P=.05) and 4.9 months in the retrospective cohort (n=1054).

Following adjustment, the total duration of transplantation evaluation was longer if the donor participated in paired donation (6.6 months) and if the recipient was referred later relative to the donor’s evaluation start date (0.9 months [per month of delayed referral]). The results depended on whether the recipient was receiving dialysis therapy.

The researchers cited some limitations to the study, including examining data from donors only, the lack of information on program-level factors that may explain variability in donor evaluation times, using proxy dates to estimate some evaluation times, and the possibility that the results may not be generalizable to living donor programs in other countries with different healthcare systems and processes for donor evaluation.

In conclusion, the researchers said, “This study was prompted by a consensus that an evaluation time of 6 months is too long for many donors. The transplantation community needs to further explore and define the reasons why some candidates experience prolonged evaluations and why some transplantation centers have much longer evaluation times than others. Better understanding of these reasons can inform quality improvement initiatives to improve the experiences of candidates going through the evaluation process.”

Takeaway Points

  1. Researchers conducted an analysis of data from one prospective and one retrospective cohort study conducted at multiple transplantation centers in Canada and Australia to estimate the time required for donors to complete the evaluation process.
  2. The median total duration of transplantation evaluation was 10.3 months; the median duration from start of the evaluation process to donation was 7.9 months, and from approval to donation, 0.7 months.
  3. Following adjustment, the total duration of transplantation evaluation was longer if the donor participated in paired donation.