Data analysis
Data are indicated as mean ± standard deviation (SD) (Gaussian
distribution) or median (range) (Skewed distribution) for continuous
variables and as numbers and percentages for categorical variables.χ 2 (categorical variables), student t-test (normal distribution)
were used to detect the differences among different FET lengths (binary
variable). Categorical variables were compared across groups using
Fisher’s exact test. Values were considered statistically significant
when P <0.05. All the analyses were performed with the
statistical software packages R (http://www.R-project.org, The R
Foundation) and EmpowerStats (http://www. empowerstats.com, X&Y
Solutions, Inc, Boston, MA).