Extended-criteria donors in lung transplantation in Switzerland: an evaluation of two adapted lung donor scores

Abstract

AIM Various scoring systems aim to assess the quality of organs donated for transplantation on the basis of patient characteristics, clinical examination and laboratory results. How well such scoring systems reflect the practice in lung transplantation in Switzerland has never been studied. Therefore, we evaluated two scoring systems for their ability to predict whether or not donor lungs are accepted by the two Swiss lung transplant centres. METHODS We retrospectively analysed patient data of adult deceased organ donors in Switzerland between 1 July 2007 and 30 June 2014. Included were all donors from whom at least one organ was transplanted. We evaluated two lung donor quality scores, the multicentre-developed Eurotransplant donor score (EDS), and the single-centre-developed Zurich donor score (ZDS). Both scores were slightly adapted to be applicable to Swiss deceased organ donor data. We evaluated whether these scores can predict whether lungs were transplanted or refused by Swiss transplant centres, using univariate logistic regression. We further assessed their discriminative power by calculating the area under the receiver operating characteristic curve (AUC). RESULTS Of the 635 donors included in our analysis, 295 (46%) were accepted as lung donors by one of the two lung transplant centres in Switzerland. Our analysis showed that both scores can predict whether or not a donor lung is likely to be accepted for transplantation in Switzerland. As the score value of a donor increases, the odds of the lung being transplanted significantly decreases (odds ratio [OR] 0.58, 95% confidence interval [CI] 0.51–0.65 for the adapted EDS; OR 0.35, 95% CI 0.28–0.43 for the adapted ZDS). This effect is slightly more pronounced in the adapted ZDS than in the adapted EDS. The discriminatory power of the scores from the AUC was 0.719 (95% CI 0.680–0.758) for the adapted EDS, and 0.723 (95% CI 0.681–0.760) for the adapted ZDS, which for both was deemed fair discrimination. CONCLUSIONS Both scoring systems are able to predict whether or not donor lungs are accepted by the two Swiss lung transplant centres. As an alternative to adapting an established scoring system, a national lung quality score could be derived de novo. This could be based on a logistic regression analysis including the most relevant donor characteristics. However, such a new score would need to be validated on an independent sample and ideally tested for its predictive value in terms of post-transplantation outcome.

Keywords

• lung transplantation
• extended criteria donors
• organ donor quality score