Effect of prolonged expressive writing on health outcomes in breast cancer patients receiving chemotherapy: a multicenter randomized controlled trial.

PURPOSE: This study aims to evaluate the effects of prolonged expressive writing on health outcomes in breast cancer patients undergoing chemotherapy to help understand how the dosage of an expressive writing intervention might moderate its effects. METHODS: A total of 112 breast cancer patients undergoing chemotherapy were randomly allocated to the expressive writing group (n = 56) or the prolonged expressive writing group (n = 56). The expressive writing group received the standard expressive writing intervention based on Pennebaker's prompt to write for at least 20 min over four consecutive days (4 sessions). The prolonged expressive writing group used a modified prompt: write for at least 20 min 3 times a week over a 4-week period (12 sessions); patients could choose whether to write on consecutive days or not. All participants were required to write about their stressor-related upsetting or traumatic feelings about breast cancer. Outcomes were assessed and compared at baseline, as well as 1 month, 3 months, and 6 months postintervention. RESULTS: There was no significant difference in the patients' quality of life, or physical and psychological wellbeing between the expressive writing group and the prolonged expressive writing group at any time point (all p > .05). The quality of life of breast cancer patients significantly decreased in the two groups over time (F = 40.64, p < .001). CONCLUSION: Our findings suggest that the writing dosage does not moderate the effects of expressive writing on breast cancer patients undergoing chemotherapy. TRIAL REGISTRATION: ChiCTR1800016278.