Causation and workers compensation

Causation is a fairly a complex topic; and, inherently, because fact situations will differ, as will medical opinion, and given the array of legislative difference and case law interpretation, it is not something you can have a rule of thumb about; or determine in a clear cut way.

The basics are that per section 53 of the (NT) Return to Work Act (RTWA), the injury has to ‘result in’ or ‘material contribute’ to incapacity.  Section 4(6A) and section 4(8)refer to employment ‘materially contributing’ and that employment must be ‘the real proximate or effective cause’ of the injury.

Let’s assume there is an injury and the employment results in or materially contributes to incapacity ie work causes the injury.   What happens afterwards when life or other events come about that bring about incapacity?  For example, pregnancy?  An unrelated assault?  Later multiple sclerosis?   Schizophrenia?  The list can go on.

Some of the things to consider include:

  • whether there has been a break in the chain of causation.
  • the nature and extent of the impact of the relevant event on the provision of suitable duties.

In a workers compensation text, regarding the chain of causation, before novus actus (new intervening act) ‘will be regarded as the only cause of the incapacity, it must be shown that the incapacity which would have resulted from the injury has ceased to exist and that the incapacity which does exist has resulted from the new cause as the sole cause.’

The principle here is that ‘causation is resolved as a matter of common sense and experience…that causation was a question of fact; but it was a question of fact into which considerations of policy and value judgments necessarily entered.’   If an ‘injury’  sets in train a series of events then, if the chain is unbroken and provides the relevant causative explanation for the incapacity or impairment, compensation is payable.’

In a 2012 NSW Workers Compensation Commission decision, a worker was injured on 19 Jan 07 (left elbow, falling at a car park).  Then, ‘at Ms Dyer’s house on 12 January 2009 to provide her with assistance with bathing, a nurse/carer inappropriately touched her. As a result, the nurse was charged with offences under s 611 of the Crimes Act 1900, but was ultimately acquitted.’

Ms Dyer already had secondary psychological injury from the original injury to her elbow.   Because of the 12 Jan 09 incident, Ms Dyer developed a post-traumatic stress disorder and suffered a further aggravation of her depressive condition.  Was the PTSD compensable? The employer argued the PTSD  had no connection with any feature of Ms Dyer’s employment and that the incident on 12 January 2009 was a novus actus that broke the chain of causation.  It was decided Ms Dyer’s PTSD psychological condition could not be found to have resulted from the injury to the elbow on 18 January 2007 and that it could not be either a primary psychological injury or a secondary psychological injury under s 65A’ (of the NSW legislation).

In another NSW case (Cannon v The Healthy Snack People Pty Ltd), ‘the worker suffered a physical injury in the course of her employment. On her return to work on suitable duties, she suffered a psychological injury as a result of harassment over her ‘suitable duties’’. It was determined this harassment was not part of the causal chain. Therefore, the psychological injury had not arisen ‘as a consequence of, or secondary to, a physical injury’, but had resulted from the harassment, which was a separate cause.’

Regarding medical treatment, an employer will be liable for the consequences of reasonably necessary medical treatment, even if that treatment is provided carelessly (unless the treatment was inexcusably bad, in which case it might break the chain of causation).

In relation to pregnancy, in Myer Sydney Limited v Buckley (1980), the NSW Court of Appeal ‘held that an injured worker with a partial incapacity for work, who was unable to perform any work at all during a pregnancy, was entitled to receive weekly compensation benefits for the persisting partial incapacity for work during the pregnancy.’   In NSW, there is a particular provision in their 1987 Act that requires things like maternity leave to be taken into account when exercising the discretion under s40(1) of the 1987 NSW Workers Compensation Act (to determine the weekly amount that the worker is earning or would be able to earn in suitable employment).

In another case, the NSW Compensation commission decided weekly compensation should reduce during periods of incapacity brought about by taking of maternity leave.  In Hirst v Illawarra Area Health Service (2000) the Court concluded ‘that at least certain aspects of the injured worker’s subsequent pregnancy and giving birth would be incompatible with employment…’.

Regarding pregnancy, aside of workers compensation, there are workplace and discrimination laws applying, including adverse action risks that need also need to be understood.

The facts and medical condition, the nature of the events post injury; the particular state or Territory legislation and the case law interpretation does not allow for easy summation or conclusion.  However, we need to be aware to identify the issues and apply the appropriate legal principles in these matters (and take into account that ‘questions of fact, degree, matters of opinion, impressions, speculation and estimation’ are required‘ for the exercise of common sense and judgment’).

We hope this assists to raise food for thought; and please note the above discussion is provided for general information only; and it is not legal advice.