The Bradford Hill criteria as applied by the Council are as follows:

The strength of an association is usually estimated by the size of a statistical measure called the relative risk (or odds ratio). A strong association is more likely to be causal than a weak association. However, epidemiological studies are not like laboratory experiments where hypotheses can be tested and accepted or rejected with some precision. The nature of epidemiological studies is that they are not precise. They deal with probabilities of association, and it is a fact that, even in the most well conducted study, an association might be observed that is due to chance alone.

Studies may be affected by bias. This is not to say that there is any intentional bias on the part of researchers, but it may be that one or both of two groups being compared might not, for some reason, represent correctly the subjects of their class in the over-all population, or the information about them has been obtained from the two groups in different ways. Bias alone can produce weak relative risk estimates of up to twofold or so.

Studies may be affected by confounding factors. Confounding occurs where the association between an exposure to a factor and the incidence of a disease is due to a third element that is independently associated with both the exposure and the disease. A well known example of confounding is the association between coffee drinking and lung cancer. The confounding results from the joint association of coffee drinking and lung cancer with cigarette smoking. Coffee drinking neither causes lung cancer nor causes people to smoke, but smoking causes lung cancer and people who smoke have been found to be more likely to drink coffee.

A dose response effect is related to the strength of association. It demonstrates that increasing exposure to the relevant factor increases the relative risk. It should be noted that weak dose response effects can be the result of bias and uncontrolled confounding.

Consistency of findings is the next most important criterion. If there are multiple studies conducted using different methods and in different populations showing an association, this indicates that the association is less likely to be due to chance, bias or confounding.

A basic time relationship is that the effect should follow the cause. Another relevant time relationship, especially in relation to malignant neoplasms, is that there is often a lead time of some years between exposure to the causal factor and the observed effect.

Another indication tending to support the suggestion of a causal association is if a biological process can be shown that connects the exposure to the manifestation of the disease in humans. While animal studies can provide some hypothetical biological plausibility, they should bear some direct relationship to the biological processes that are known to occur in humans. Animal studies are insufficient on their own.

Specificity of association refers to the observation that exposure to a factor is associated with a single type of disease or a few closely related diseases. This criterion is not as important as the other criteria, because it is known that exposure to one factor may give rise to a number of different diseases. But, non-specificity of outcomes for a particular type of exposure is often indicative that the result is affected by bias.

Coherence is an overview which incorporates, in a unified structure, all of the available evidence, both human and animal, that satisfies each of the other Bradford Hill criteria.

As can be seen from the above, epidemiological criteria require that, in assessing whether certain information is sound medical-scientific evidence, it is necessary to test it against all of the other available information concerning the issue in question. It is contrary to the principles of epidemiology to consider one study in isolation, for to do so is to deny the operation of important epidemiological criteria such as consistency, coherence, biological plausibility, dose response, and specificity. In that regard, it is relevant to note that subsection 196C(3) of the Act provides that, in forming any view during an investigation, the Repatriation Medical Authority may rely only on sound medical-scientific evidence and "must consider and evaluate all the evidence" made available to it. The Council is under a similar obligation when conducting a review: subsection 196W(2) provides that the Council "must carry out a review of all the information that was available to the Authority".

In its written request to the Council, under section 196Y, AVADSC stated that its grounds for seeking a review were that:

In its first written submission, AVADSC repeated that it considered that smoking should have been included in both Statements of Principles, and provided a report, dated 1 May 1995, entitled, "Smoking and prostate cancer", prepared for the VVAA (NSW) by Mr Veigel of the Toxic Chemicals Consultancy of the Total Environment Centre Inc, and a different report also entitled, "Smoking and prostate cancer", prepared by Professor Gabriel A Kune.

On 28 September 1995, Professor Kune wrote to the Council, providing it with a copy of a paper entitled, "Smoking and cancer mortality among US veterans: a 26 year follow-up", by JA McLaughlin, Z Hrubec, WJ Blot and JF Fraumeni Jr., which had been published in Int J Cancer: 60, 190-193 (1995).

In its supplementary submission, AVADSC stated that due consideration was not given by the Repatriation Medical Authority to variations in types and qualities of tobacco. A paper prepared for the NSW Ex-Prisoners of War Association Inc by Dr David Pope was attached.

At the meeting, Mr Alexander submitted that the Repatriation Medical Authority had not taken into account the different types of tobacco and that prisoners of war, especially, smoked tobacco and other leaves that contained higher levels of poisons than in commercially produced cigarettes or tobacco.

Mr Alexander submitted that cancers in all other parts of the body have been shown to be caused by cigarette smoking and that it was not reasonable to exclude cancers of the prostate from being caused by smoking. He submitted that bladder cancer had been accepted as being related to cigarette smoking, and that the close proximity of that organ to the prostate gives credence to the proposition that cigarette smoking causes prostate cancer.

In its request for review, the VVAA (NSW) indicated that the reason for its request was that the Repatriation Medical Authority had not included the use of tobacco products in Statement of Principles No.95 of 1995.

In its written submission, the VVAA (NSW) provided to the Council the same reports as provided by AVADSC. Additionally, Professor Kune, on behalf of the VVAA (NSW), provided the Council with a report that he had prepared, entitled, "Association between smoking and prostate cancer".

At the meeting, Mr McCombe submitted that animal studies relating to cadmium and N-nitrosamine exposure supported the epidemiological studies that he suggested had shown an association between N-nitrosamines and cadmium in cigarette smoke and prostate cancer. He suggested that a synergistic effect operated between the cigarette smoking and other factors to cause prostate cancer.

He submitted that the Repatriation Medical Authority had found a link between smoking and every other cancer that it had considered. He indicated that tobacco is a multi-site carcinogen and that it causes many other cancers a long way from the site of exposure.

Mr McCombe submitted that the size of the US veterans study prevented chance playing a part in the outcome, and that the narrowing of the confidence intervals relating to the relative risk made it more certain.

He submitted that Honda had found no link between diet and lifestyle and prostate cancer and that they could not be considered to be confounding factors.

Mr McCombe also submitted that the dose-response shown in studies at least indicated that a synergistic effect operated. He suggested that cadmium and N-nitroso compounds could operate by interference with testosterone levels.

He also relied on the literature review provided by Mr Veigel of the Toxic Chemicals Consultancy of the Total Environment Centre Inc, stating that this supported the proposition that smoking caused prostate cancer.

Mr McCombe stated that he supported the submission of the Repatriation Commission in relation to retaining in the Statement of Principles the factor relating to exposure to herbicides in Vietnam.

In its written submission, the Naval Association stated that smoking should have been included as factors in the Statements of Principles and that exposure to herbicides and pesticides during World War 2, and in Korea, Malaya and Borneo should have been included as factors.

At the meeting, Commander Fahey submitted that herbicides and pesticides were used during World War 2, as well as the Korean, Malaysian, Borneo and Vietnam operations, and that all of those theatres of operations should be reflected in the Statements of Principles in relation to herbicides and pesticides.

He submitted that smoking suppresses the auto immune system, thus rendering a person more susceptible to cancer.

He suggested that if one area of the body were sensitive to cigarette smoking, then why not the prostate. He noted that bladder cancer had been associated with cigarette smoking and, given the bladder's close proximity to the prostate, it should be probable that prostate cancer was also associated with cigarette smoking.

Commander Fahey suggested that cancer is a disease to which people have a genetic predisposition, and that cigarette smoking is a trigger in the disease process. He stated that cadmium in cigarette smoke does not degrade but is accumulated in the body.

Commander Fahey noted that the Repatriation Commission had previously accepted cigarette smoking as a cause of prostate cancer and that the Repatriation Medical Authority should not have rejected that view until there was positive proof that smoking is not associated with prostate cancer.

The Returned and Services League provided a written submission by way of a report from Dr Alan King, in which he suggested that cigarette smoking could result in prostate cancer. Dr King suggested that at high temperatures in burning cigarettes, the carcinogens in the complex mixture of chemicals in the smoke become volatile, and upon entering the bloodstream, are distributed throughout all organs of the body, including the prostate, in a fraction of a second after the commencement of smoking. He suggested that enlargement of the gland against the tight capsule of the gland could possibly impede the circulation of the blood, causing areas of stasis of the circulating carcinogens.