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).