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A confirmatory study of violence risk assessment tool (M55) and demographic predictors of patient violence
Kristyn Ideker1, Dale Todicheeney-Mannes, Son Chae Kim
1School of Nursing, California State University, Long Beach, California, USA.
Aim:
The aims of this study were to confirm the usefulness of Violence Risk Assessment Tool (M55) for prospectively identifying violent patients in medical-surgical units and to explore predictors of Code-55 activation for violent behaviour or physical attack.
Background:
A previous retrospective case-controlled study claimed moderate sensitivity and high specificity of the M55 in identifying potentially violent patients. However, the usefulness of M55 needs to be confirmed in a prospective study before wide adoption.
Methods:
A prospective cohort study of patients in medical-surgical units of a hospital in southern California was conducted from August 2009 to December 2009. A checklist containing the M55 was completed on admission. Following a violent event or just prior to discharge, the violent event outcome section of the data collection tool was completed. The sensitivity and specificity of M55 for identifying the violent patients were calculated using the original M55 flagging criteria.
Results:
Of 2063 patients, 32 (1·6%) had a violent event of Code-55 activation (12), physical attack (26) or both (6). The M55 showed a low sensitivity (41%) and acceptable specificity (99%) for prospectively identifying violent patients. The multivariate logistic regression model indicated higher odds of violent events for patients ≥70 years of age [odds ratio (OR) = 2·3; 95% confidence interval (CI): 0·9-5·7], males (OR = 2·7; 95% CI: 1·2-6·1) or Caucasian (OR = 3·4; 95% CI: 0·8-14·7).
Conclusion:
The M55 does not appear to be useful for prospectively identifying violent patients in medical-surgical units because of low sensitivity. Older, male or Caucasian patients had higher odds of becoming violent.
Insights
The Violence Risk Assessment Tool (M55) has low sensitivity for prospectively identifying violent patients. Older, male, or Caucasian patients showed increased odds of violent events in medical-surgical units.
Area of Science:
- Medical-Surgical Nursing
- Patient Safety
- Violence Risk Assessment
Background:
- Previous retrospective studies suggested moderate sensitivity and high specificity for the M55 tool.
- Prospective validation was needed to confirm the M55's clinical utility in identifying violent patients.
Purpose of the Study:
- To validate the Violence Risk Assessment Tool (M55) for prospective identification of violent patients.
- To identify predictors associated with Code-55 activation for violent behavior or physical assault.
Main Methods:
- A prospective cohort study involving 2063 patients in Southern California medical-surgical units.
- The M55 checklist was administered upon admission; outcomes were recorded via a data collection tool.
- Sensitivity and specificity of M55 were calculated using original flagging criteria.
Main Results:
- 1.6% of patients experienced a violent event (Code-55 activation, physical attack, or both).
- M55 demonstrated low sensitivity (41%) but high specificity (99%) in prospective identification.
- Predictors for violence included age ≥70, male gender, and Caucasian ethnicity.
Conclusions:
- The M55 tool is not sufficiently sensitive for prospectively identifying violent patients in medical-surgical settings.
- Older age, male gender, and Caucasian race are associated with a higher likelihood of patient violence.
