All tests were 2-tailed and a P-value of <0.05 was considered statistically significant. Statistical analysis was performed using IBM Statistics for Windows, version 23.0 (IBM Corp. Released 2015. IBM SPSS Statistics for Windows, Version 23.0. Armonk, NY, USA: IBM Corp.) and R, version 3.5.1 using the Survival package, version 2.43–3 (R Foundation for Statistical Computing, Vienna, Austria).