Table 1.

Summary of selected quantitative studies

Reference	Setting	Level/ grade	Study design	Intervention	Outcome	Results (grade)
Arnetz et al 7	USA, 7 hospitals, 41 units, 2800 employees	Level 2 Moderate	RCT intervention 5 years, 4 phases Data-driven, worksite-based intervention Plan-Do-Check-Act Hazard risk matrix to identify high-risk units in intervention and control groups	Plan-Do-Check-Act model Data-driven and worksite-based intervention Stakeholder involvement	Rates of violent events Rates of violence-related injuries Intervention group compared with control group Evolution over time compared with baseline	Rates of violent events: Six months postintervention, incident rate ratio (IRR) of violent events was significantly lower on intervention units compared with control IRR 0.48 (95% CI 0.29 to 0.80) Rates of violence decreased slightly but not significantly in the intervention group compared with baseline and increased significantly in the control group compared with baseline. Significantly increased violent event rates at 24 months compared with baseline in both groups: intervention group from 8 to 13.8 per 100 FTE and control group from 8 to 15.4 per 100 FTE. Violence-related injuries: 24 months postintervention, the violence-related injury was lower on intervention units compared with control IRR 0.37 (95% CI 0.17 to 0.83). Remark: results were not consistent over time during the 24-month follow-up period.
Abderhalden et al 28	14 acute psychiatric wards, 2364 patients, Switzerland, PSY	Level 2 Moderate	RCT: 14 acute psychiatric wards, 2364 patients phase 1: 3 months baseline data phase 2: 3 months intervention period	Structured short-term risk assessment : Swiss version of the BrØset Violence Checklist, 2 times per day during the first 3 days In case of high risk (1 in 10 patients will physically attack during next shift): discuss possible prevention measures from the list In case of very high risk (1 in 4 patients): multidisciplinary team discussion on preventive measures and plan and implement preventive measures	Risk assessment Incident rates Staff Observation Aggression Scale Attacks Coercive measures	Significant reduction in severe events of patient aggression: adjusted risk reduction 41% intervention vs control 15%, p<0.001. Significant reduction in attacks: 41% vs 7%, p<0.001. Significant reduced need for coercive measures : 27% reduction in intervention group vs 10% increase in control, p<0.001. Admitted psychiatric patients combined with a communication of risk scores and a recommendation for action tailored to risk level reduced the incidence rate of coercive measures and severe aggressive incidents.
JE Arnetz and BB Arnetz42	47 healthcare workplaces 1500 nurses in EDs, geriatric, psychiatric, home healthcare, Sweden, ED, Psy, GER	Level 3 Low	RCT Implementation and evaluation of a practical intervention programme for dealing with violence towards healthcare workers	Form of violent incidents in the intervention and control groups Structured feedback programme in the intervention group	Awareness of risks of violence Ability to deal with aggressive situations Exposure to violent incidents	Better awareness of risk situations and of how to deal with aggressive patients (low). 50% increase in incident reporting in the intervention group compared with the control group (low).
Lipscomb et al 14	Mental health facilities, New York state, 26 units: 6 units selected, Psy	Level 3 Low	Evaluation of the impact of OSHA guidelines on workers’ health and safety Three intervention groups, three comparison groups Baseline and postintervention survey 4 years study	OSHA guidelines serve as framework Management commitment to the violence prevention programme Employee involvement in VPP Hazard assessment activities Hazard control activities: infrastructural, organisational, environmental, administrative, behavioural Training	Staff perception of quality of programme elements Frequency of reported threats and physical assaults in intervention and comparison facility preintervention and postintervention	Staff in both intervention and comparison groups reported significant improvements in the first four elements of the OSHA elements (low). Intervention facilities reported significant improvement in the training element (low). No significant reduction in the change in physical assaults in the intervention group nor in the comparison group. Significant increase in threats of assault in the intervention group (+98%, p<0.001), a non-significant increase in the comparison group (+47%, p=0.08). Remark: both the intervention and the comparison groups did implement safety preventions but the comparison groups did not benefit from the support of the team resources of the worksite violence study.
Magnavita36	Small-scale psychiatric unit, Italy, about 85 workers	Level 3 Low	Preintervention and postintervention comparison test	Aggression minimisation programme as part of total quality management Architecture and work organisation: Rearrangement of building three assistance areas depending on severity of mental illness Increased nurse-to patient ratios, staff coverage Remove patients from monitoring tasks Improved lighting Safety alarms Education	Violence incident form Assault rate: preintervention and postintervention Assault rate for aggression using physical force Verbal abuse, and so on, not addressed	Mean assault rate per employee was significantly reduced from 0.24 per year to 0.04 per year after the intervention Stable decline over time in assaults after the intervention
Kling	Acute care hospital, Canada, 109 cases	Level 3, Low	Preintervention and postintervention study evaluation of the violent risk assessment system and retrospective case control	Violence risk assessment flagging in patient file and on wrist band and violence prevention training taking precautions such as: wearing personal alarm, security team nearby, not entering patient room alone, not having sharp objects	Violent incidence risk Adjusted OR for violence in flagged patients	During intervention compared with preintervention RR hospital: 0.57 (0.33–1.83) (not significant). RR direct patient care workers: 0.52 during intervention (0.33 to 0.81). RR high-risk department: 0.39 (0.24 to 0.61). Postintervention compared with preintervention. RR hospital 1.01 (0.989 to 1.04). RR direct patient care workers 1.03 (1.00 to 1.06). RR high risk department: 1.04 (1.01 to 1.07). In contrast to hypothesis: Adjusted OR for violent incident 6.28 for patients flagged by the alert system.
Mohr et al, 15	138 veterans healthcare facilities	Level 3 Low	Longitudinal study Impact of implementation of a workplace prevention programme on rates of workplace violence over a period of 6 years: 2004–2009  Relationship of assault rates with workplace violence dimension score Percentage change in assault rates in 2009 compared with 2004	Implementation of a workplace violence prevention programme Workplace violence prevention dimension score	43 workplace violence prevention items, grouped into three dimensions : training, workplace practices, environmental control and security Standardised assault rate	Overall there was an increase in assault rates over time: from 59 to 71 per 10.000 FTE. 34% of facilities had reduced assault rates, average improvement 42%. Facilities with no reduction had an average increase of 125% in assault rate. Training dimension: significant but moderate 5% reduction on standardised incidence rate (low). No significant change in assault rates over time. Possible explanation: Large differences in facilities in assault rate reduction or increase. Under-reporting prior to the workplace violence prevention programme. Reduction in severity of assaults (workers compensation claims declined 40% between 2001 and 2008).
Hvidhjelm et al 44	Forensic psychiatry, 156 patients, Denmark, Psy	Level 3 Low	Population-based observational study Sensitivity and specificity of the BrØset Violence Checklist 156 patients, checked three times per day during 24 months	BVC six items checklist as predictor of short-term (<24 u) risk of violence Score six items: presence or absence of: confusion, irritability, boisterousness, physical threat, verbal threat, attack on objects	Risk of violence within 24 hours	BVC showed overall satisfactory specificity and sensitivity as a predictor of short-term risk of violence, (low) score ≥3: Sensitivity : 65.6% Specificity 99.7% with overall risk 0.3%: PPV score ≥1: 17.5%. PPV score ≥3: 37%. NPV score <3: 99.9%.
Partridge and Affleck45	ED, 2046 patients, Australia	Level 3 Low	Population-based observational study Statistical utility of the BrØset Violence Checklist by a security officer in the ED	Predicting aggressive patient behaviour using the BrØset Violence Checklist by security officers in ED	Short-term risk of violence	BVC showed a good sensitivity, specificity and predictive value of short-term risk of violence, (low): overall risk 1.7% Score ≥1: PPV 16.7%, LR +11.6, sensitivity 88.6%, specificity 92.4%. Score ≥2 : PPV 34.2%, LR +30.3, sensitivity 65.7%, specificity 97.8%. Score ≥3: PPV 55.2%,LR +71.4 sensitivity 45.7%, specificity 99.4%.
Morken and Johansen 24	210 emergency primary care centres, Norway, GP	Level 5 Very low	Cross-sectional study, survey on application of 22 safety measures items in 210 emergency primary care centres	Available staff: extra person during home visit when needed (44%), more then one person on duty (30%). Reception design with glass barrier (86%), view to entrance (62%) and waiting rooms (72%). Consulting room set-up: alternative exit (59%), quick entrance/exit for staff (46%), patient not sitting between clinician and door (29%). Electronic safety systems: alarm on medical radio network (74%), automatic door lock (54%), portable alarm (28%), CCTV camera (28%), and so on. Training (40%). Reporting: monitor and follow-up of violence episodes (75%). No reporting of number of violent incidents. 98% response rate. No results on effectivity. Application of measures give indication on perceived usefulness of recommendations and feasibility of recommendations.
Nau et al 46	63 nursing students attending training course, Germany	Level 5 Very low	Longitudinal pretest and post-test study The development and testing of a training course in aggression for nursing students	3 days training course	Confidence in coping with patient aggression 10-item scale No results on actual performance in healthcare settings	Enhanced self- confidence score in managing aggression from 2.5 to 3.6 (very low). Training should be seen as a valuable initial step in developing aggression-related requirements.
Schat and Kelloway35	Healthcare setting 225 employees in healthcare	Level 5 Very Low	Organisational support: reducing adverse consequences of workplace aggression Survey, moderated multiple regression	Secondary prevention: moderating effect of organisational support: instrumental support (eg, support from co-workers) and informational support (eg, training) on negative consequences of workplace aggression and violence	Fear of future violence Emotional well-being Somatic health scale Job-related affect Job neglect	Instrumental support: positive effect on variance of (3%–6%) : emotional well-being, somatic health, job-related effect. No effect on fear of future violence and job neglect (very low). Information support: positive effect on variance of (3%–6%) emotional well-being, no effect on other outcomes (very low). No effect on: fear of future violence and job neglect.
Ifediora 23	General practice, Australia, 300 doctors of National Home Doctors Service after-hours house call services	Not applicable	Survey: exploring the safety measures by doctors on after-hours house call services	No study of impact on incidents of violence. 57% response rate. Safety measures by doctors on after-hours call services: Overall 43% of doctors adopted protection measures while on after-hours house calls. Use of chaperones/security personnel: 34%. Dependence on surgery policies such as vetting and blacklisting risky patients, documenting doctor’s destinations: 31%. De-escalation or self-defence techniques: 15%. Panic buttons: 7%. Personal alarms: 6%.
Hills and Joyce47	Australia, clinical medical practice, 9449 doctors of which 3515 GPs	Not applicable	Cross-sectional study, self report survey of implementation of 12 prevention and minimisation actions MABEL Survey	No report on effectivity of measures. Implementation of recommendations: Policies, protocols for aggression prevention and management: 66%. Warning signs in reception: 49%. Alerts to high risks of aggression: 52%. Restricting or withdrawing access to services for aggressive persons: 45%. incident reporting and follow-up: 68%. Education & training: 53%. Alarms : 47%. Clinician escape: 23%. Optimised lighting, noise level, comfort and waiting time in waiting area: 52%. Patient access restriction: 62%. Building security system: alarm, camera, and so on: 70%. Safety measures for after-hours on-call work or home visits: 34%.
Geoffrion et al 33	1141 healthcare workers and law enforcers, Canada, GEN	Not applicable	Survey: individual and organisational predictors of trivialisation of workplace violence among healthcare workers and law enforcers.		Normalisation of violence as being ‘part of the job’ Taboo: avoiding open discussion, fear of being stigmatised as incompetent	Discussion on under-reporting. Individual factors in healthcare: Men are more likely than women to consider workplace violence as part of the job (34% vs 23%) and perceived a taboo (54% vs 42%). Staff with more than 15 years of work experience are more likely to tolerate workplace violence as part of the job. Organisational factors: colleague and employer support, training, zero tolerance policy contribute to normalisation of violence but decrease the likelihood of taboo.

ED, emergency department; GP, general practitioner; RCT, randomised controlled trial.