The Effect of Augmenting OPTN Data With External Death Data on Calculating Patient Survival Rates After Organ...

Although the Organ Procurement and Transplantation Network (OPTN) database contains a rich set of data on United States transplant recipients, follow-up data may be incomplete. It was of interest to determine if augmenting OPTN data with external death data altered patient survival estimates.

Solitary kidney, liver, heart, and lung transplants performed between January 1, 2011, and January 31, 2013, were queried from the OPTN database. Unadjusted Kaplan-Meier 3-year patient survival rates were computed using 4 nonmutually exclusive augmented datasets: OPTN only, OPTN + verified external deaths, OPTN + verified + unverified external deaths (OPTN + all), and an additional source extending recipient survival time if no death was found in OPTN + all (OPTN + all [Assumed Alive]). Pairwise comparisons were made using unadjusted Cox Proportional Hazards analyses applying Bonferroni adjustments.

Although differences in patient survival rates across data sources were small (≤1 percentage point), OPTN only data often yielded slightly higher patient survival rates than sources including external death data. No significant differences were found, including comparing OPTN + verified (hazard ratio [HR], 1.05; 95% confidence interval [95% CI], 1.00-1.10); P = 0.0356), OPTN + all (HR, 1.06; 95% CI, 1.01-1.11; P = 0.0243), and OPTN + all (Assumed Alive) (HR, 1.00; 95% CI, 0.96-1.05; P = 0.8587) versus OPTN only, or OPTN + verified (HR, 1.05; 95% CI, 1.00-1.10; P = 0.0511), and OPTN + all (HR, 1.05; 95% CI, 1.00-1.10; P = 0.0353) versus OPTN + all (Assumed Alive).

Patient survival rates varied minimally with augmented data sources, although using external death data without extending the survival time of recipients not identified in these sources results in a biased estimate. It remains important for transplant centers to maintain contact with transplant recipients and obtain necessary follow-up information, because this information can improve the transplantation process for future recipients.