3.2  | Results of meta-analysis
Due to significant heterogeneity between groups, anxiety, depression, and fatigue will be selected for meta-analysis, and pain and quality of life for descriptive analysis.
3.2.1 | Anxiety meta-analysis
Of the six studies included, four studies14, 16, 18, 19 reported the effect of IVR techniques on anxiety in breast cancer patients, and 3 studies16, 18, 19 focusing on breast cancer chemotherapy patients and choosing a random-effects model, showed that IVR relieved patients’ anxiety compared to the control group, with a statistically significant combined effect size [I2=79%, SMD=-2.06,95% CI=(-2.73,-1.40),P<0.0001] (Figure 3). Sensitivity analysis was performed using a literature-by-literature exclusion approach, when excluding Chirico et al.[18] , Cao et al.14 ’s studies, the heterogeneity decreased significantly and the difference was statistically significant [I2 =16%, SMD=-1.52, 95% CI=(-1.88,-1.15), P<0.0001] (Figure 4). The heterogeneity may be related to the different measurement tools, study populations, and intervention durations.