Two types of risk assessment are possible within the CRA framework: attributable burden and avoidable burden.13 Attributable burden is the reduction in current disease burden that would have been possible if past population exposure had shifted to an alternative or counterfactual distribution of risk exposure. Avoidable burden is the potential reduction in future disease burden that could be achieved by changing the current distribution of exposure to a counterfactual distribution of exposure. Murray and Lopez13 identified four types of counterfactual exposure distributions: theoretical, plausible, feasible, and cost-effective minimum risk. In GBD studies, to date and in this study, we focus on attributable burden using the theoretical minimum risk exposure level, which is the distribution of risk comprising the levels of exposure that minimise risk for each individual in the population.
