Strength Of Association

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Question One
Strength of Association: Strong associations are more likely to be causal compared to weak associations.
Criticism: The existence of weak association does not rule out causality and may still be of significant effect on the disease under study. This is applied in a case where the exposure is in a common population. For instance passive smoking and lung cancer (Risk Ratio: 1.3) (Morein & Stuart, n.d).
Consistency: Repeated observation of an association in a different population under different circumstances showing the same results suggests that the results of a single study are not due to chance.
Criticism: This should be applied cautiously to avoid chances of mistaking the statistical significance for consistency. Different
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The cases were more likely to mow the lawn than their controls; this was the evidence of a causal relationship. However, the experiment did not take into consideration the gender aspect, as the cases were male despite the equal distribution of females and males. Therefore, it was misleading to present the findings without taking gender into account (Morein & Stuart, n.d).
Coherence: Coherence between the epidemiological knowledge of the disease and the laboratory findings increases likelihood of an effect.
Criticism: Absence of coherence cannot be taken as evidence against causality and vice versa.
Experiment: Causation is likely if evidence is based on random experiments.
Criticism: Certain study designs may provide more convincing evidence than others. Sometimes experiments outcomes rely on how well they are laid out and how they are carried out (Morein & Stuart, n.d).
Analogy: The effects of similar factors may be considered.
Criticism: It’s considered a weak criterion for causality but it’s useful in predicting how a risk factor can operate in different contexts (Morein & Stuart, n.d).
Question Two
This ranking is based on the evidence retrieved from the four studies which explore the relationship between soy consumption and breast cancer by Sacks et al (2006), Messina & Loprinzi (2001), Wu et al (2008), and Trock et al (2006). The arrangement starts from the most evidential criteria to the least evidential criteria from the
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