Development of Violence Severity Scale in Serious Mental Illness

Abstract

Objective :

To develop a violence severity scale in serious mental illness namely “Prasri Violence Severity Scale (PVSS)” and assess its properties.

Material and Methods :

Scale development was conducted with 2 steps. First, qualitative approach and review literature for initial pool of items, designing, content validity and cognitive testing was performed. Second, psychometric properties testing for concurrent validity and internal consistency were evaluated. There were 2 groups of sample. Step 1 involved 50 participants consisting of 20 patients with psychosis, 10 of their caregivers, and 20 psychiatric nurses. Step 2 involved 118 patients with serious mental illness as violence. Descriptive statistic was used. Concurrent validity with clinical global impression scale (CGI) by using exploratory factor analysis, Spearman correlation coefficient, cronbach’s alpha coefficient

Results :

The PVSS rating scale consists of nine items and two domains as the following ; 1) domestic violence 2) suicide and factors relating to violence. The total explained variance was 79.63%. Spearman correlation coefficient showed convergent validity with CGI rs = 0.75, p <.001. Internal consistency of scale with Cronbach’s alpha coefficient= 0.89.

Conclusion :

The nine items PVSS scale had a high internal consistency and good concurrent validity. It can be used as a tool for assessment of violent severity.