Workers Compensation Act 1987

For this part, an unexpected and material deterioration in a worker’s condition since the worker’s last assessment was made occurs only if—

at the time of the last assessment, there was no reasonable cause to believe the worker’s condition would deteriorate, and

the deterioration results in an increase in the worker’s degree of permanent impairment of at least a further 10 percentage points.

Age-related deteriorations must not be considered in deciding whether an unexpected and material deterioration in a worker’s condition has occurred.