Statistical Analysis
Statistical analysis was performed with Microsoft Excel (Microsoft 365 MSO, Version 2405 Build 16.0.17628.20006, 64-bit). If means and standard deviations were not reported in the study of interest, they were manually calculated from the data provided if possible. For combining data, means were weighted based on study population size and standard deviations were pooled based on unequal study population sizes, and a two-tailed paired t-test was performed with P < 0.05 as the cutoff for significance. Reported data was converted to common units of measurement if possible, however some data was incomplete and unable to be converted without additional information. Review Manager (Version: 8.0.0, REVMAN) was used for the metanalysis. A random effects model was used if heterogeneity existed. When pooling the data in the studies, the means, standard deviations, p-values, and 95% confidence intervals (CI) were calculated in either Microsoft Excel or REVMAN. Heterogeneity was assessed with the I2 statistic (inconsistency levels: low = 25%, moderate = 50%, high = 75%) and the Cochran Q statistic, with significant heterogeneity considered when P < 0.1 was obtained. If heterogeneity existed, a sensitivity analysis was performed by removing each of the studies to identify the source(s). The null hypothesis for this study was that no difference exists between pre- and post- DISE-directed tongue surgery PSG outcomes for our study population.