Antecedents
As well as type and severity of aggression, the OAS-MNR builds on the OAS by also enabling information regarding various environmental and other variables that can inform formulations regarding why patients engage in aggressive behaviour to be captured. Two sets of events that precede aggression are recorded. First, one of three possible ‘setting events’, that is, environmental factors which may not directly elicit aggression themselves, but which influence the probability that this will follow an immediate antecedent. These are numbered from 1-3 and are: ‘1’ the aggression took place within a structured activity (for example, a formal rehabilitation session); ‘2’ the environment was judged to have been noisy at the time of the incident; and ‘3’ seizure activity had taken place 24 hours or less beforehand. Second, the immediate antecedent observed to directly precede an aggressive behaviour is recorded. Fifteen are defined within the OAS-MNR numbered ‘11’ to ‘25’. For example, ‘11’ is “given direct verbal prompt to comply with instruction”. If no obvious antecedent was observed then ‘24’ is recorded. If any antecedent that is not defined within the scale is observed ‘25’ is used and a brief description of what this comprised is written by the observer.
Interventions
The final recording to be made concerns the intervention used to manage aggression. Fourteen are described in the scale, each being designated by a letter of the alphabet from A-N. In addition to the eleven interventions described in the original OAS a further three were added to include strategies used in neurobehavioural rehabilitation. Thirteen of the intervention strategies describe discrete action taken by staff in order to manage an aggressive incident (for example, ‘seclusion’). The remaining category is that of ‘other; if an intervention is employed that is not described in the OAS-MNR then the letter for ‘other’ (‘N’) is recorded on the scale and a brief written description of what was done is made.
Convenient Shorthand
Using the tool, a set of codes can be used as a shorthand means of capturing objective detail regarding potentially complex sequences of behaviour. For example, ‘1, 11, VA3, A’ reflects the presence of a possible setting event (1 - ‘structured activity’), that the immediate antecedent was that the patient had been ‘given a direct verbal prompt to comply with an instruction’ (11), which had resulted in verbal aggression rated as severe (VA3 – ‘swearing, moderate threats clearly person directed at others or self e.g. “Fuck off you bastard”), that had been managed using an intervention that minimised the likelihood of reinforcing that behaviour (A – ‘behaviour ignored or “played down” completely’).
How Intrusive are Interventions?
In addition to information about aggression, the authors of the OAS-MNR proposed a means of quantifying the intrusiveness of interventions. These were produced by asking a group of twenty clinicians to independently rate twelve of the interventions in rank order of intrusiveness; the mean ranking was then assigned to each of these as an indicator of how invasive it is, using a conceptual framework that advocated behaviour should be managed using the least restrictive or intrusive means possible. As a result, the least intrusive method is ‘behaviour ignored or “played down” completely’ which is assigned a rating of 1, whilst the most invasive means of managing aggression is that of ‘immediate medication given by injection’ which is rated 12.
The authors also introduced a system of weighting severity of aggression to further differentiate between the different types of aggressive behaviour. Using this scheme, verbal aggression ratings remain unchanged (1-4) as this category is seen as the least severe. However, severity ratings for other types are multiplied by two, three or four (for physical aggression against objects, self and others respectively). Quantifying the intrusiveness of interventions and weighting severity of aggression by distinguishing between the different types creates further outputs from the scale that can be studied: for example, with regard to clinical outcome, reduction in intervention intrusiveness and weighted severity scores over time can also be used along with a decrease in the frequency of aggression as markers of progress.
All of the codes and descriptors for the components of the OAS-MNR are defined on one side of A4 paper; a separate recording sheet enables these to be systematically documented, as in the preceding example (all the documentation to run the OAS-MNR is downloadable from the website). Staff should receive training in the use of the scale. In our service it is routinely employed with the expectation that all behaviour observed that fits the written descriptions of aggression is recorded, irrespective of staff beliefs regarding the intent of the patient in deliberately engaging in that act.
Psychometric Properties
The authors demonstrated that the OAS-MNR had good inter-rater reliability with weighted Kappa values in excess of .90, and good convergent validity as evidenced through moderate correlations between weighted severity and intrusiveness intervention.
OAS-MNR Outputs
The OAS-MNR has seen widespread use and has been successfully employed in clinical work, research, outcome measurement and service evaluation [4 – 8]. Most recently, a method which utilises OAS-MNR records to produce an ‘aggregate aggression score’ that can be used as a performance indicator that testifies to the effectiveness of services in managing aggression has been described [9].
SASBA
In 2008 the ‘St Andrew’s Sexual Behaviour Assessment’ (SASBA) scale was published [10]. This tool shares the same operant framework for understanding potentially inappropriate sexual behaviour as the OAS-MNR and was designed to be used in conjunction with it.
Availability
The OAS-MNR and SASBA are currently being used within neurorehabilitation services in the UK and abroad. Although they were primarily designed for use with people who have acquired and progressive neurological conditions, they have also been found to be useful in other services for other clinical populations, including those for men, women and adolescence within St Andrew’s Healthcare. All the documentation required to run both scales can be downloaded free of charge from the St Andrew’s Healthcare website, and advice is available regarding their various applications.
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