Psychosocial assessment and repetition of self-harm: The significance of single and multiple repeat episode analyses

Background: Self-harm is a common reason for presentation to the Emergency Department. An important question is whether psychosocial assessment reduces risk of repeated self-harm. Repetition has been investigated with survival analysis using various models, though many are not appropriate for recurrent events. Methods: Survival analysis was used to investigate associations between psychosocial assessment following an episode of self-harm and subsequent repetition, including (i) one repeat, and (ii) recurrent repetition (<= 5 repeats) using (a) an independent episodes model, and (b) a stratified episodes model based on a conditional risk set. Data were from the Multicentre Study on Self-harm in England, 2000 to 2007. Results: Psychosocial assessment following an index episode of self-harm was associated with a 51% (95% CI 42%-58%) decreased risk of a repeat episode in persons with no psychiatric treatment history, and 26% (95% CI 8%-34%) decreased risk in those with a treatment history. For recurrent repetition, assessment was associated with a 57% (95% CI 51%-63%) decreased risk of repetition assuming independent episodes, and 13% (95% CI 1%-24%) decreased risk accounting for ordering and correlation of episodes by the same person (stratified episodes model). All models controlled for age, gender, method, history of self-harm, and centre differences. Limitations: Some missing data on psychiatric treatment for non-assessed patients. Conclusions: Psychosocial assessment appeared to be beneficial in reducing the risk of repetition, especially in the short-term. Findings for recurrent repetition were highly dependent on model assumptions. Analyses should fully account for ordering and correlation of episodes by the same person. (C) 2010 Elsevier B.V. All rights reserved.