The Psychiatric Impairment Rating Scale (PIRS) is used for the assessment of Whole Person Impairment (WPI) in accordance with the State Insurance Regulatory Authority (SIRA) Motor Accident Guidelines and Workers Compensation Guidelines.
With a single injury and where pre-injury functioning was normal, the calculation is straightforward. The client is assessed in the areas of Self-Care, Social and Recreational Activities, Travel, Social Functioning, Concentration, Persistence and Pace and Adaption/Employability and rated on a scale from 1-5 in severity.
In the context of pre-existing impairment from a non-psychiatric cause, this is taken into consideration within the assessment. But in cases where there is a pre-existing psychiatric condition the Motor Accident Guidelines require that two PIRS tables be completed, one demonstrating current impairment and the other demonstrating pre-accident psychiatric impairment. The latter score is deducted from the current impairment to obtain a final WPI. A similar approach is required in cases where there has been a subsequent psychiatric injury.
The Workers Compensation Guidelines utilise the same approach but in cases where calculation of the pre-accident impairment is “difficult to calculate”, the assessor may deduct 10% from the current impairment in lieu of using a second table. Ultimately, an accurate result demands a thorough history of pre-accident and post-accident functioning with careful explanation of the reasoning for each impairment class.
Further information can be found at the website for the State Insurance Regulatory Authority (SIRA).