Spss statistic software for windows version 22

Continuous variables were presented as mean ± standard deviation (SD) and categorical variables as frequencies and proportions. Paired t-test, intraclass correlation coefficient (ICC) and Bland Altman limits of agreement were used for strain comparisons across techniques. ICC and coefficient of variations were used for inter- and intra-observer agreement analysis. All p-values were considered to be significant when < 0.05. The analysis was performed using SPSS Statistic software for Windows, Version 22.0 (International Business Machines, Inc., Armonk, New York, USA).

The data were recorded on a PC using a Microsoft Excel XP database sheet. The statistical analyses are performed using IBM SPSS statistic software for Windows (version 22.0). The data from the excel database sheets were compared by using statistical test techniques.
To compare the means, several techniques, in which independent samples t test and paired samples t test, were used. The ANCOVA test was used to correct for correlations between means. With the revision of the article, we also performed a sensitivity analysis to determine the minimum inter/intragroup difference/effect size, based on the given sample size, alpha and beta error. Data about the effectivity has been illustrated in scatter plots. Further, we made tables concerning the AHI values on T1 and T2, ∆T1 T2: MAD 1 compared to MAD 2, the correlation ∆T1T2 to T1, and the correlation ∆T2T2 to T1 corrected for T1.
Subgroups and interactions were not present in our study. As it is a retrospective study, there were no missing data. Patients with missing values were excluded. Out of 628 patients, there were 137 patients with all data available selected. There was no loss of follow-up.