Measuring the relationship between overt aggression and expectations: a methodology for determining clinical outcomes

The presence of aggressive behaviour following traumatic brain injury imposes special challenges within rehabilitation centres. Survivors of traumatic brain injury constitute a heterogeneous population amongst whom problems with increased irritability and aggression are characteristic. There is a clear need to determine what treatment approaches might be helpful in reducing aggressive behaviour. Whilst single-case experimental methodologies including reversal and multiple baseline designs seem ideal for this purpose, the compelling need to minimize risk can compromise their deployment, especially when aggression takes the form of physical assaults on others. When this is the case, there are difficulties in assessing whether a change in aggressive behaviour represents a successful response to treatment or is simply a function of reduced demand in the environment. The contributions made to understanding the relationship between aggression and expectations made on patients participating within rehabilitation will be explored here. A possible means of quantifying demands using the Neurobehavioural Expectations Scale will be described. Three case studies are presented that suggest that a methodology that employs concurrent use of this tool with the Overt Aggression Scale -- Modified for Neurorehabilitation, can enable objective evaluation to be made of the effects of rehabilitation on behaviour, without increasing risk.