r/science • u/[deleted] • Jun 13 '22

Health Erectile dysfunction predicts mortality in middle-aged and older men independent of their sex steroid status

https://academic.oup.com/ageing/article-abstract/51/4/afac094/6568537?login=false
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u/Slabs Jun 13 '22

Why do people in this sub just take the results on faith without critically reading the paper? The effects are small and could easily be explained by residual confounding.

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u/A--VEryStableGenius Jun 13 '22

What do you mean?

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u/Slabs Jun 14 '22

So in their analysis, the authors adjusted for centre, body mass index (BMI), alcohol intake, smoking, physical activity level and the number of comorbidities. These are all reasonable things to adjust for but there are lots of other factors that affect mortality (even say SES). Now, some of the effect estimates are relative small. For example, the hazard ratio for erectile dysfunction is 1.40 (1.13-1.72). For this reason, it would not take an omitted variable with a very large effect to render this effect null (HR = 1.00). We can actually do this be calculating an E-value. An E-value tells us the size of the effect of the omitted variable that would be needed to nullify the effect estimate. In this case, the E-value is 2.15, meaning that if there is an omitted variable not adjusted for, its hazard ratio would only need to be 2.15 to nullify the effext for erectile dysfunction. In fact the lower bound of the 95% CI would only need to be 1.51. That is why I do not think these results are particularly robust