EBM Episode 3: irrelevant research

This is the third episode in our series on EBM. In it we explore what it means for evidence to be irrelevant.

Irrelevant evidence occurs when research produces results that may be accurate but are not pertinent for decision making. For example, a clinical trial that measures reduction in LDL cholesterol rather than reduction in risk of heart disease is irrelevant to patients trying to avoid heart disease. It's true that LDL is thought to predict risk of heart disease but artificially reducing LDL does not reduce the risk.

If irrelevant research is produced, can it just be ignored? It can, but that doesn't make it any less of a problem.

Consider the opportunity cost: Patients used in an irrelevant trial were not used in a relevant one; money spent on an irrelevant trial is not spend on a relevant one.

There's also the time cost to clinicians who now have to spend more time sifting through irrelevant trials to find the relevant ones for their patients.

Irrelevant research is usually also misleading. A trial that shows one can reduce LDL, might lead regulator to think the drug is effective, clinicians might think it's a good strategy to reduce risk of heart disease (remember, the trial didn't show that, but it also didn't show that risk wasn't reduced).

Clinical Outcome Assessments: Conceptual Foundation—Report of the ISPOR Clinical Outcomes Assessment – Emerging Good Practices for Outcomes Research Task Force