B.2 Additional considerations

B.2.1 Health behaviours with non-monotonic relationships

Health behaviours with relationships that are non-monotonic (always increasing or always decreasing) can be used in health behaviour attributable calculations but special consideration may be warranted for both policy and analytic reasons.

An example of a health behaviour with a non-monotonic relationship is alcohol. Some studies suggest that there is a “J” shaped risk relationship for outcomes such as cardiovascular disease.

Is this still a consideration if we are using 0 as the reference value? Need to complete the thought at the end of the paragraph Alcohol drinking guidelines usually do not recommend people: non-drinkers or former-drinkers, initiate drinking. In this situation, the target population for health behaviour attribution calculations can be restricted to for respondents with moderate or higher drinking, or multiple reference exposures could be created.

B.2.2 Health behaviours with interactions or multiple coefficients

The health behaviour attributable risk and the health behaviour-deleted risk estimates can be calculated for health behaviours with interaction terms, including complex interactions or multiple coefficients. Examples include:

health behaviour parametes with age interaction;
spline functions with terms for each knot point; or,
composite risks such as smoking which may coefficients for smoking status (current, former, never) and pack-years.

All coefficients that related to a common risk factor should be simultaneously considered.