Comparative Disease Assessment: a multi-causal approach for estimating the burden of mortality

Background The Comparative Risk Assessment (CRA) framework comprehensively evaluates the impact of exposure to risk factors on health populations using the counterfactual causal approach. Methods We propose a framework, Comparative Disease Assessment (CDA), for assessing the impact of exposure to morbidity from some diseases on health outcomes, particularly death from other (relevant) diseases. This framework has been developed following the ideas of the CRA framework and using the widely accepted concept that exposure to morbidity is usually a risk factor for health outcomes (morbidity/mortality) related to other diseases. Our framework uses a counterfactual and not a categorical approach when attributing the burden of health outcomes to potential causes. Results This paper describes the different steps and assumptions required to implement the CDA framework, and an illustrative example is used considering diabetes mellitus morbidity as a risk factor for death from heart diseases. Conclusions One advantage of the CDA framework is that it can be applied using multi-causal death registries. Some assumptions are needed to implement it in order to avoid biases, but at least it can provide preliminary estimations of the impact of exposure to diseases as risk factors for deaths from other diseases. Another main advantage is that the burden of deaths is no longer attributed to a single cause, the underlying cause, as it is almost always done. Finally, this framework provides information on the pattern of comorbidity in a (sub)population of subjects who is about to die. These patterns can be used as a reference for alternative patterns of the general population or patterns of other specific subpopulations.