Red cell distribution width is associated with mortality in kidney transplant recipients.

Background: Red cell distribution width (RDW), a parameter routinely reported as part of the complete blood count, is associated with increased morbidity and mortality risk in different patient populations. No published data are available about the association between RDW and mortality in kidney transplant recipients.

Methods: We collected socio-demographic, clinical parameters, medical and transplant history and laboratory data at baseline in 723 prevalent kidney transplant recipients between June and October 2008 [mean age 51 ± 13 (SD) years, 56 % men, 21 % diabetics]. Associations between baseline RDW values and all-cause mortality over 3 years were examined in unadjusted and adjusted models.

Results: Increasing RDW was associated with increased mortality in both unadjusted [(HR(1 % increase) = 1.63; 95 % CI 1.41-1.89) and (HR(>median) = 2.74; 95 % CI 1.68-4.48)] and fully adjusted models [(HR(1 % increase) = 1.60; 95 % CI 1.27-1.89) and (HR(>median) = 1.33; 95 % CI 0.76-2.35)]. In reclassification analyses, RDW improved the predictive value of all-cause mortality prediction models [the net reclassification improvement (NRI) was 0.189; p < 0.001].

Conclusions: RDW, a cheap and readily available but largely neglected parameter independently, predicts mortality in prevalent kidney transplant recipients and could potentially been used in everyday risk assessment of kidney transplant recipients.