The statistical analysis was carried out with SPSS v 23.0 for Windows
(SPSS, Chicago, IL) and statistical significance was determined at
p<0,05. One-way ANOVA test was used to evaluate BIS averages
of SQI groups and comparison of sleep stages according to BIS score
averages of SQI values over 70. Post hoc Tukey test was used to compare
variables that were found significant.