Factors affecting assessment of severity of aggressive incidents: using the Staff Observation Aggression Scale – Revised (SOAS-R) in Japan

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  Consumer gender and age, and nurse gender influenced the perception of overall severity of aggressive incidents, in addition to the aggression data provided by the Staff Observation Aggression Scale – Revised (SOAS-R) scores.
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  The factors influencing assessments of aggression incident severity can be identified from the severity scores provided by concurrently conducting objective (i.e. SOAS-R) and overall (i.e. visual analogue scale) assessments.

The aim of this study is to investigate factors associated with overall judgements of aggression severity as provided by ward nurses, using the Japanese-language version of the Staff Observation Aggression Scale – Revised (SOAS-R). Nurses who observed 326 aggressive incidents involving psychiatric inpatients at five mental health facilities in Japan provided their assessments of the incident severity both on the established rating scale, the SOAS-R, and on a visual analogue scale (VAS), a one-item scale to indicate overall aggression severity. To evaluate the factors influencing the VAS severity scores, a multiple regression analysis was performed, in which consumer, nurse and ward characteristics were added consecutively, along with SOAS-R severity scores as independent variables. SOAS-R scores explained 17.6% of the VAS severity scores. Independently from the SOAS-R scores, the gender and age of the aggressive consumers (adjusted R²= 10.0%), as well as the gender of the nurses who reported the aggression (adjusted R²= 4.1%), each explained VAS severity score to a significant degree. Apart from the SOAS-R scores, consumer and nurse characteristics appeared to influence the overall judgements of severity of aggressive incidents, which may be connected to decisions about the use of coercive measures, such as seclusion/restraint or forced medication.