> Despite including thirty-eight articles, a systematic review was opted for over a meta-analysis due to heterogeneity in research methods, including the popula

> Despite including thirty-eight articles, a systematic review was opted for over a meta-analysis due to heterogeneity in research methods, including the population of interest, study design, noise characteristics, sleep measurement methodology, sleep outcomes, and statistical analyses, if any. As such, effect size calculations could not be conducted. Is it normal to not do any kind of statistics? Can you even draw any conclusions by just counting the number or studies as if they were all created equal?