The Staff Observation Aggression Scale – Revised (SOAS-R) – adjustment and validation for emergency primary health care

A substantial number of workers in emergency primary health care experience aggressive behaviour such as verbal aggression, threats or physical violence from patients or visitors [1]. These incidents are a threat to the safety and wellbeing of both health care workers and patients [2, 3] A review on workplace violence states that adopting simple incident-reporting procedures is helpful in ensuring safe working environments [4]. Such procedures can protect the worker from retribution, ensure managerial support, and support the implementation of preventive solutions. Simple incident-reporting procedures exist for inpatient, psychiatric care [5]. However, to our knowledge no similar form for simple incident-reporting has been developed for other health care settings. Health care services providing emergency and accident medical care are services at high risk of workplace violence [6–8]. These services differ from inpatient, psychiatric care by providing easily accessible and unscheduled care for an unselected and largely unfamiliar patient population. They deal with the whole range of clinical scenarios, from minor medical illnesses to serious medical conditions, traumas, toxic exposures, substance abuse and psychiatric emergencies.

In Norway, emergency and accident care is provided by general practitioners in emergency primary care clinics, and we know that one in three employees has been physically attacked during their worktime career [1]. Aggressive incidents seem to be underreported [9], and simple incident-reporting may increase knowledge about and ability to deal with workplace violence. However, the forms developed for inpatient settings have limited relevance outside hospital wards due to differences in service organization, range of clinical scenarios and familiarity with the patients. The aim of this study was therefore to adjust a pre-existing form for reporting aggressive incidents in a psychiatric inpatient setting to the emergency primary health care settings. We also wanted to assess the validity of the severity scores in emergency primary health care.

The incident reporting form used in this study was developed from the Staff Observation Scale - Revised (SOAS-R). SOAS-R is easy and quick to fill in, can be used without previous training, and has been shown to give a valid approximation of the severity of aggressive incidents [5, 10]. In 1987, Palmstierna and Wistedt constructed the Staff Observation Scale to monitor frequency, nature and severity of aggressive incidents which are damaging or threatening to objects or humans in psychiatric wards [11]. The scale was revised in 1999, forming the currently used SOAS-R [5], and is used in psychiatric settings worldwide [12]. The SOAS-R report form is completed when a staff member observes aggressive behaviour on the part of a patient. It consists of five columns (categories), and each column comprises several options to characterise the actual incident. Several options can be marked in each column. The five columns have the following themes: 1) The provocation that leads to the aggressive incident; 2) The means used by the aggressor during the incident; 3) The target of aggression; 4) The consequences for victims; and 5) The immediate measures taken to stop or control aggressive behaviour.

In the original SOAS, the severity scores were developed based on face-validity [11], while in SOAS-R the scoring system was further developed and designed statistically to increase the validity [5, 13]. A total score system was developed to rate overall severity of an aggressive incident [5]. Each option in the columns was given a score, and the column score equalled the highest scoring option of each column. The total severity score was derived by adding the five column scores. The SOAS-R total severity score ranges from 0 to 22 points, with scores of 0–7 indicating mild, 8–15 moderate, and 16–22 severe severity [12]. A SOAS-R severity score of 9 or more includes all incidents where physical pain or injury is inflicted. A score of 9 or more also includes all physical attacks causing fear of harm to the victim, as well as attacks with dangerous objects directed at a person [14].

In addition to the five columns, a 100-mm Visual Analogue Scale (VAS) is often added to the SOAS-R form to judge the severity of the incident [5]. The VAS is found to be suitable for assessment of subjective phenomena [15], and has also been validated for assessing occupational stress [16]. On the VAS, the worker marked the severity of the aggression on a scale ranging from “not severe at all” (at the 0-end of VAS) to “extremely severe” (at the 100-end of the VAS).

A total of 350 SOAS-RE forms from ten different casualty clinics were registered of which 26 forms lacking VAS severity scores and 33 forms lacking SOAS severity scores were excluded from the analysis. The remaining 291 forms were completed by 202 female workers (69.4%) and 76 males (26.1%). Information on gender was missing in 13 forms (4.4%). There were 231 nurses (79.4%), 41 physicians (14.1%), 13 other professionals (4.5%) and 6 with unspecified profession (2.1%). Four persons (1.4%) reported that they had been alone on duty.

SOAS-RE total severity scores ranged from 1 to 22. The mean severity score of SOAS-RE was 10.0 (SD = 4.1) and the mean VAS severity score 45.4 (SD = 26.7). The scatterplot (Fig. 1) shows the relationship between SOAS-RE and VAS severity scores. The Pearson correlation between the two scores was 0.45 (p < 0.001). There were two outliers defined as standardized residual greater than 3. When these were omitted, the correlation was 0.48 (p < 0.001).

No gender differences were found in SOAS-RE severity score (p = 0.145) or in the VAS severity scores (p = 0.071). There was no association between the age of the worker and the SOAS-RE severity score (p = 0.950) or the VAS severity score (p = 0.638).

Several measures for incident reporting of patient violence and aggression towards healthcare providers have been developed, most of them for hospital settings [22]. The SOAS-R was adjusted to emergency primary health care, and found to be well suited for this context, as it is short, easy to fill in, and combines the visual analogue severity scale with a description of elements of the actual incident. Furthermore, as opposed to similar registration forms like Arnetz Violence Incident Form [23], the SOAS-RE helps the healthcare leaders and risk managers to identify and act on the severity of the incident itself and by judging the subjective impact the incident had on the healthcare worker involved, shown by the healthcare worker’s VAS score. The new form can thus be used both to register incidents and to identify employees in need to follow up independent of the severity of the actual incident reported. The new form was named The Staff Observation Aggression Scale - Revised Emergency (SOAS-RE). The mean severity scores of 10.0 in SOAS-RE were similar to SOAS-R mean severity scores found in other studies, ranging from 9.2 to 11.0 [12]. There was a significant correlation of 0.45 between the VAS severity ratings and the SOAS-RE severity scores. However, the correlation was higher between VAS and the original SOAS-R (0.62) [5]. The moderate relationship between VAS and SOAS-RE severity scores suggest that SOAS-RE and VAS cannot be substituted for one another in measuring severity of aggressive incidents. As has been claimed by the developer of the SOAS, the subjective measurement by VAS severity score may be more influenced by intraobserver variation than the established severity scoring system of SOAS-R [5]. The staff members’ individual emotional reactions, previous experiences and attributions could affect their propensity to report aggressive episodes and perceived subjective severity [24]. The VAS severity score could therefore be used to identify individuals who perceive the incident as severe, and to ensure follow up of vulnerable individuals independently of the SOAS-RE score.

The SOAS-RE ratings are part of a comprehensive system for monitoring aggressive behaviour and provide a broad array of characteristics of aggressive incidents as well as their severity [10]. The SOAS-RE form may be suitable primarily to describe the content of the incidents and to prioritize preventive measures based on the factual information.

Column 2 (Means used by aggressor) was most strongly connected to the VAS severity score in SOAS-RE and were more strongly connected to the VAS than was found in SOAS-R [5]. It is likely that the intrusiveness of the aggression is more powerful in determining the emotional response, than other aspects of the incident. This might be the case particularly in a setting where aggression is mostly unexpected and the health care worker is unfamiliar with the aggressor. The other columns reflected the same relative contribution as in SOAS-R.

In column 1, involuntary assessment of health condition as provocation of aggressive behaviour had a relatively low mean VAS score, while the SOAS-RE score was relatively high. The professionals judged involuntary assessment as of the highest severity in column 1 in the SOAS-RE scoring system. However, the staff may expect violence in situations with involuntary assessment [18], and might therefore mobilize other personnel or implement other preventive measures to increase their own safety. The situation might therefore be perceived as safer than when violence is completely unexpected, as it might be more difficult to receive the help needed in the latter situation.

The SOAS-RE seems to be a useful instrument for research, incident-recording and management of incidents in emergency primary care. The moderate correlation between SOAS-RE severity score and the VAS severity score shows that application of both these severity ratings is needed to ensure appropriate follow up of workers affected by workplace violence.