The Effect of Theory-Guided Positive Psychological Interventions for Patients With Breast Cancer: A Systematic Review and Meta-Analysis.

Only five randomised trials and 412 patients were included, so the evidence is limited. Only English-language studies were included, and all came from the United States, China or South Korea, so cultural and healthcare-system differences may limit generalisability. The interventions were heterogeneous, differing in content, format, duration, frequency and facilitator. Only two studies had low risk of bias across all domains, and only two were rated low risk for selective reporting. Small sample sizes and differences in breast cancer stage raise concerns about robustness. Secondary psychological and somatic outcomes were reported by too few trials to be pooled. Long-term effects were not evaluated. The review did not identify the optimal duration or frequency of intervention.

The authors declared no conflicts of interest. The supplied publication types note non-U.S. government research support, but the supplied text does not name the funder or describe its role.

Do not read the pooled quality-of-life improvement as proof that one named programme works. Five different theory-guided interventions were combined, including expressive writing, mind subtraction meditation with self-management education, and family-centred online health education, and the supplied text does not report separate effects for each component.