Sample size assessment: A recent meta-analysis reported a study which showed that Guided Written Disclosure Protocol reach on effect size of 0.89 on psychosocial outcomes (Gidron et al., 2002; Mogk et al., 2006). Power analysis showed that with an alpha of 0.05 and a power of 0.80, we needed a sample of 34 participants to detect effect sizes of 0.89 and higher.~Plan for missing data: Occasional missing values were imputed by calculating, for each participant, the average score for each subscale and then replaced.~Statistical analysis plan: We conducted a 2 (group) X 2 (time [pre-treatment vs. post-treatment]) repeated measures multivariate analysis of variance (MANOVA) for a set of variables.
We conducted a randomized-controlled trial of Guided Written Disclosure Protocol for dermatological patients with the aim of reducing psychological distress, expressive suppression, and skin-related symptoms, and improving spiritual well-being, cognitive reappraisal, and sense of coherence.