Review framework for list of occupational diseases

The list is Schedule 2 of the Accident Compensation Act 2001 (AC Act). Cabinet approved this review framework on 16 September 2022.

Schedule 2 is based on the International Labour Organization’s List of Occupational Diseases (ILO List)^[1].  Prior to the development of ACC, Aotearoa New Zealand and international workers compensation schemes supported workers who had injuries that developed gradually (including occupational diseases).

The framework supports MBIE’s regulatory stewardship of the AC Act. MBIE will undertake an initial determination of whether a review is needed every five years. This will provide a regular, evidence-based approach to inform how Schedule 2 is reviewed to ensure it reflects diseases that working New Zealanders experience. The Minister for ACC will provide an update to the House of Representatives on the outcome of the decision to review Schedule 2 or not and the rationale. This will provide transparency about what is involved in the review from the beginning. The objectives of the framework are set out below and an evaluation of the framework against these objectives will be completed as soon as practicable after the implementation of the pilot review.

The use of the framework can also address gaps in our understanding of how occupational diseases impact different population groups in Aotearoa New Zealand. As part of using this framework, independent researchers and medical experts will be expected to take a gender-sensitive approach (as recommended by the ILO^[2]) to their analysis of different occupational diseases against the technical criteria.

The outcome of using the framework will inform, if needed, a change to Schedule 2 by an Order in Council. Apart from Acts of Parliament, Orders in Council are the main method by which the government implements decisions that need legal force. 

Objectives

• Clinical and epidemiological knowledge: How well Schedule 2 reflects this current knowledge
• Clarity: The review is easy to understand
• Transparency and consistency: Honesty and openness about what is involved in the review, including an evaluation of the framework against these objectives as soon as practicable after implementation of the review
• How well the option maintains existing coverage: The outcome of the review does not narrow or expand the scope of ACC’s coverage.

Review framework

Technical criteria

Criteria to establish a causal relationship

Strength of association

The greater the impact of an exposure on the occurrence or development of a disease, the stronger the likelihood of a causal relationship.

Consistency or reproducibility

Consistent findings observed by different persons in different places with different samples strengthen the likelihood of an effect.

Specificity

Causation is likely if there is a very specific population at a specific site and disease with no other likely explanation. The more specific an association between a factor and an effect is, the bigger the probability of a causal relationship.

Temporality or time sequence

The effect has to occur after the cause (and if there is an expected delay between the cause and expected effect, then the effect must occur after that delay).

Biological gradient

Greater exposure should generally lead to greater incidence of the effect. However, in some cases, the mere presence of the factor can trigger the effect. In other cases, an inverse proportion is observed: greater exposure leads to lower incidence.

Biological plausibility

From what is known of toxicology, chemistry, physical properties, or other attributes of the studied risk or hazard, it makes biological sense to suggest that exposure leads to the disease or injury.

Coherence

A general synthesis of all the evidence (eg, human epidemiology and animal studies) leads to the conclusion that there is a cause-effect relationship in a broad sense and in terms of general common sense.

Analogy

The use of analogies or similarities between the observed association and any other associations.

Experimental evidence

This can be considered if relevant.

Criteria to establish if the causal connection between the disorder and employment is sufficiently strong to enable automatic acceptance of a claim

Insufficient causal evidence

Diseases will be excluded if evidence of the causal connection between the disorder and employment is not sufficiently strong to allow a connection to work to be automatically accepted.

‘Sufficiently strong’ here is not generally quantifiable. For each condition on Schedule 2 it will need to be based on an expert assessment of the evidence available and its quality.

Proportion of work cases

Diseases will only be included if employment is the cause of the disorder in a significant majority of the cases of that disorder in a subset of the population, identified based on the subset’s exposure to particular work tasks, or particular work environments.

Further material

Cabinet papers and decisions relating to the review framework.

Footnotes

1. It is a requirement under the ILO Convention 42, to which Aotearoa New Zealand is a party, for members to provide compensation to workers incapacitated by occupational diseases.
2. ILO, '10 Keys for Gender Sensitive OSH Practice - Guidelines for Gender Mainstreaming in Occupational Safety and Health'(external link) [PDF 2MB], 2013.