Spss statistical package v 18.0 for windows

Normal distribution of variables was checked using the Kolmogorov Smirnov and Shapiro–Wilk tests. Variables with normal distribution are presented as mean ± SD. Variables with skewed distribution were log-transformed before analyses and are presented as median (25–75th percentiles). Categorical data are shown as percentages. Clinical and laboratory characteristics were compared among groups using One-way ANOVA tests or χ²-tests, as appropriate. MiRNA expressions were compared between groups using Kruskal–Wallis tests. Correlations between quantitative variables were analyzed using Spearman’s correlation tests. All statistical analyses were performed using the SPSS statistical package (v.18.0) for Windows (SPSS Inc., Chicago, IL, United States), and P-values <0.05 were considered statistically significant.
The sample size was calculated in the OpenEpi site¹ and based on previous studies (Cardenas-Gonzalez et al., 2017 (link); Xie et al., 2017 (link)). Considering a power of 80% (α = 0.05) to detect two fold changes (±1.5 SD) in miRNA expressions between case and control groups, we needed at least 10 patients in each group in order to have an adequate statistical power.

Variables with normal distributions are shown as mean ± standard deviation (SD),
while variables with skewed distributions were log-transformed and then showed
as median (25-75^th percentiles). Categorical variables are shown as
%. Variables related to clinical and laboratory data and lncRNA expressions were
compared between case and control groups using One-way ANOVA,
Student’st or χ² tests. Spearman’s tests were
used to evaluate correlations between quantitative variables. Statistical
analyses were carried out using the SPSS statistical package (v.18.0) for
Windows (SPSS Inc, Chicago, IL). Statistical significance was considered when P
values were lower than 0.05.
Using the OpenEpi web tool (https://www.openepi.com), we calculated that at least 9 patients
in each group were required to have adequate statistical power (β = 80% and α =
0.05) to detect 2 fold change (± 1.5 SD) differences in lncRNA expressions
between groups.