What are the concerns of the committee regarding the selection bias in the REFER study?
The committee voiced concern about the very small proportion of HF-REF patients in the REFER study population. The committee considered that this may be due to study selection bias, as patients with severe symptoms, who are thought to be of high risk, are often not recruited into these types of clinical studies due to concern that there would be a delay in their treatment. The committee considered that the patients considered to be of high risk are more likely to have HF-REF than HF-PEF. However, the extent of possible selection bias is unknown.