Statistical Analysis
Categorical and continuous characteristics were compared between heart transplant patients who developed DNM and those who did not using Pearson’s chi-squared and two-sample t-tests. Kaplan-Meier survival analysis was performed to compute annual probabilities of developing DNM. Rates of malignancy – calculated per 100,000 person-years—were compared to the general population in the Surveillance, Epidemiology, and End Results (SEER) database using incidence ratios (IR).
Glomerular filtration rate (GFR) was calculated using the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation and categorized by stages I through V.13,14 Cox proportional hazards regression was performed to calculate hazard ratios (HR) with 95% confidence intervals (CI) for risk of DNM development, all-cause mortality, as well as cancer-specific mortality. For all statistical analyses, a p-value of <0.05 was considered statistically significant. Statistical analysis was performed using Stata version 14.2 (StataCorp, College Station, TX).