Should a Reduction in All-Cause Mortality Be the Goal When Assessing Preventive Medical Therapies?

Traditionally, innovations in cardiovascular medicine (including preventive therapies) have been assessed in terms of cause-specific morbidity and mortality. More recently, some have argued that such therapies should not be used unless they have been shown to reduce all-cause mortality. Here, we argue that such an approach is bad science and makes a mockery of evidence-based medicine.Cardiovascular therapeutics should aim to reduce mortality, but it is not necessary to demonstrate a reduction in all-cause mortality when assessing them. It is, in general, misguided to attempt to demonstrate such an effect because it is too crude a measure of either benefit or harm. Results are dominated by causes of death unrelated to the intervention—the signal-to-noise ratio is low. Most effective interventions in public health and preventive medicine that have together led to substantial improvements in life expectancy would not have been introduced had policymakers required direct evidence of an impact on all-cause mortality.An example of misinterpretation of the data is the systematic review by the US Preventive Services Task Force1 of screening for abdominal aortic aneurysm (AAA), “One-time invitation for abdominal aortic aneurysm (AAA) screening in men aged 65 years or older was associated with decreased AAA rupture and AAA-related mortality rates but had little or no effect on all-cause mortality rates.” This summary ignores the compelling evidence …