The Efficacy of Laughter Therapy on Psychological Symptoms in People With Cancer: A Systematic Review and Meta-Analysis of Randomized Controlled Studies.

Objective: Cancer patients generally have high stress levels, which often leads to depression, anxiety and other psychological problems. Laughter therapy has been used to relieve stress, depression and anxiety in cancer patients, but its efficacy is uncertain. The study aims to summarize evidence on the efficacy of laughter therapy on psychological symptoms of people with cancer.

Methods: A search was conducted in 10 electronic databases for randomized controlled trials (RCTs) reported before May 2023. This systematic review was reported based on the PRISMA 2020 statement. The evaluation of methodological quality and risk of biases were conducted by the Cochrane Risk of Bias Assessment tool version 2, and evidence evaluation was conducted using the GRADE pro online assessment tool. Statistical analysis adopted the Review Manager version 5.4 software.

Results: A total of eight studies were included involving 543 participants. Meta-analysis showed that laughter therapy plus routine nursing produced more positive effects than routine nursing in relieving stress (SMD = -1.18, 95% CI -1.73, -0.62, p < 0.0001), depression (SMD = -1.05, 95% CI -1.30, -0.81, p < 0.00001) and anxiety (SMD = -0.81, 95% CI -1.20, -0.43, p < 0.0001).

Conclusions: Laughter therapy could effectively relieve stress, depression and anxiety of cancer patients. Future studies should improve the methodological quality of randomized controlled trials, conduct appropriate follow-up, and report details of follow-up. Additionally, it should perform multi-center and large-sample studies, and combine both subjective and objective outcome indications to enhance the persuasiveness of evidence supporting the effectiveness of laughter therapy.

Trial registration: PROSPERO register: CRD 42023452739.