Meta-Analysis of Changes in Sleep Quality of Women with Breast Cancer before and after Therapy.

Cancer treatments may affect the sleep quality and even future quality of life of women with breast cancer. A meta-analysis was performed to understand the changes in the sleep quality of women with breast cancer during their treatment period. In a systematic literature review in compliance with the PRISMA guidelines, we searched for articles published between 2000 and 2018 in databases. A total of 12 study articles were included. The standardized mean differences of the pooling effect size of sleep quality between the period before treatment and 1-8 weeks, 9-16 weeks, 17-24 weeks, and 25-56 weeks after the commencement of treatment were -0.020, -0.162, 0.075, and 0.216, respectively. Although the differences were not statistically significant, in view of the heterogeneity among the studies, we conducted further analysis using a linear mixed effect model. The overall results indicated poorer sleep quality as time passed from the start of the first treatment (p = 0.014). The results of this study revealed that patients experienced better sleep quality in the initial months after the beginning of treatment; however, their sleep quality became poorer between 4 months to approximately 1 year after the beginning of treatment, compared with the sleep quality before treatment, and continued to decline rather than improve during the follow-up period.