Statistical analysis
In our research, the primary outcome was the prevalence of influenza in
COVID-19 patients and the secondary outcome was the prevalence of
clinical characterization in co-infected patients. Assessment of
heterogeneity among the studies of primary studies was performed using
the statistic chi‐squared test (Cochran’s Q) and I2index. In this results, random or fixed effect model were used for
determination of heterogeneity test and more than 50% were considered
as the degree of heterogeneity. For study heterogeneity evaluation, a
forest plot estimated with confidence intervals of 95%. (CIs;
horizontal lines). All statistical analyses were performed using
Comprehensive Meta-Analysis (CMA), V.2 software.