How to investigate excess deaths (clip)

Investigating cause of excess deaths In 1965, English statistician Sir Austin Bradford Hill Causal relationships Strength The larger the association, the more likely that it is causal Consistency, (reproducibility) Consistent findings, different persons in different places Specificity No other likely explanation Temporality The effect has to occur after the cause (often with a delay) Biological gradient, (dose response relationship) Greater exposure should lead to greater incidence of the effect (or indeed lower incident of effect) Plausibility A plausible mechanism between cause and effect Coherence Between epidemiological and laboratory findings Experiment Occasionally it is possible to appeal to experimental evidence Analogy Analogies or similarities between the observed association and any other associations Reversibility May work if there is no permanent damage