The effect of expressive writing intervention on psychological and physical health outcomes in cancer patients--a systematic review and meta-analysis.

OBJECTIVE

This study aimed to evaluate the effectiveness of expressive writing intervention (EWI) for improving psychological and physical health in cancer patients and survivors.

METHODS

We searched databases and existing reviews for randomized controlled studies published between 1986 and 2014 that evaluated the effects of EWI on psychological and physical health outcomes. We computed and combined effect sizes and examined the role of methodological characteristics.

RESULTS

From 223 unique citations, we identified 16 independent randomized controlled trials published from 1999 to 2014, examining the effect of EWI on a range of psychological and physical health outcomes. No statistically significant effects were found for any of the individual or combined psychological (Hedges's g: 0.04; 95% CI, -0.06 to 0.14; p = 0.42), physical (0.08; 95% CI, -0.05 to 0.20; p = 0.22), or quality-of-life outcomes (0.09; 95% CI, -0.05 to 0.24; p = 0.22). The results were unaffected by differences in study characteristics, for example, type of control condition, study setting, cancer type, and overall study quality ratings. Results from a subset of studies indicated a possible moderating effect of social constraints, suggesting that participants experiencing low levels of emotional support may be more likely to benefit from EWI.

CONCLUSIONS

Our results do not support the general effectiveness of EWI in cancer patients and survivors. However, given the practical and inexpensive intervention, it is possible that even small effects in subgroups of patients could be clinically relevant, and future studies are recommended to test the effects of potential moderators, including pre-intervention distress levels and context-dependent factors such as emotional support.