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Abstract: Introduction: Our previous reports suggested that African Americans (AA) are more likely to develop end-stage renal disease (ESRD) following kidney donation when compared with white counterparts. We sought information on age, gender, and race of kidney donors to determine which groups were over-represented on the kidney transplant waiting list. Methods: We queried the United Network for Organ Sharing United Network for Organ Sharing (UNOS) Organ Procurement Transplantation Network (OPTN) database for former donors who were subsequently placed on the kidney transplant waiting list. Information was retrieved on race, gender, age at donation, years between donation and listing, and diagnosis leading to ESRD. Comparisons were made to all kidney donors between 1988 and 2006 using chi-square testing. Results: In this study, 126 individual kidney donors entered the kidney transplant waiting list. Fifty of the 126 (40%) were AA (P < .0001 compared with all donors, 13% AA). For both AA and whites, male donors and those who donated before age 35 made up a larger proportion of donors on the waiting list than would be expected by their proportion of overall donors. Conclusion: AA, males, and young donors may be at higher risk for kidney failure in the years following kidney donation. Mechanisms of increased risk are unclear but deserve further scrutiny. Our data are limited by the small number of patients developing kidney failure, the lack of complete follow-up on all living kidney donors, and the possibility that older donors with kidney failure were not listed because of death or other medical conditions. We believe that discussion of long-term risks may be different for various subgroups, especially for young AA kidney donors. [Copyright &y& Elsevier]

Abstract: Objective: To assess how different imputation methods used to account for missing variance data in primary studies influence tests of heterogeneity and pooled results from a meta-analysis with continuous outcomes. Study Design and Setting: Point and variance estimates for changes in serum creatinine, glomerular filtration rate, systolic blood pressure, and diastolic blood pressure were variably reported among 48 primary longitudinal studies of living kidney donors (71%–78% of point estimates were reported, 8%–13% of variance data were reported). We compared the results of meta-analysis, which either were restricted to available data or used four methods to impute missing variance data. These methods used reported P-values, reported nonparametric summaries, results from other similar studies using multiple imputation, or results from estimated correlation coefficients. Results: Significant heterogeneity was present in all four outcomes regardless of the imputation methods applied. The random effects point estimates and 95% confidence intervals varied little across imputation methods, and the differences were not clinically significant. Conclusions: Different methods to impute the variance data in the primary studies did not alter the conclusions from this meta-analysis of continuous outcomes. Such reproducibility increases confidence in the results. However, as with most meta-analyses, there was no gold standard of truth, and results must be interpreted judiciously. The generalization of these findings to other meta-analyses, which differ in outcomes, missing data, or between-study heterogeneity, requires further consideration. [Copyright &y& Elsevier]