MATERIALS AND METHODS
Local ethics committee aproval was obtained before the study. Nine centers from various regions of Turkey were included in the study. The data of 457 patients that underwent surgery for kidney tumor in the 2-year period between March 1, 2019 and February 28, 2021 were retrospectively analyzed. The period between March 1, 2019 and February 28, 2020 was defined as 1-year period before COVID-19. The period between March 1, 2020 and February 28, 2021 was defined as 1-year period during COVID-19.

STATISTICAL ANALYSES

Statistical analyses were done with IBM SPSS (Statistical Package for the Social Sciences) version 15.0 program. The conformity of the variables to the normal distribution was examined using the Kolmogorov-Smirnov (K-S) test. It was observed that all parameters showed non-normal distribution and were analyzed by using non-parametric tests. The Mann-Whitney U test was used to compare paired groups. Pearson’s Chi-square test was used for multivariate comparisons. Results were considered statistically significant when p<0.05.