Statistical analysis
anemia, pain
ANEMIA
All analyses of related outcomes were performed according to the intention-to-treat principle. Continuous variables were assessed for normal distribution with a Q–Q plot and Kolmogorov–Smirnov test. Students Subgroup analyses were done post hoc to explore whether the overall primary outcome differed between groups (including gender, age, ASA, nutrition, cognitive levels, anemia, pain degree, time of surgery, surgery time, and anesthesia). The results are presented as a forest plot with the RRs and 95% CIs as well as 