LAUSR

The COVID-19 pandemic has fundamentally changed the way we practice medicine, conduct clinical trials, and rapidly gather, generate, and evaluate high-quality evidence to guide clinical practice. This is clearly apparent in the accelerated process of assessing and formulating clinical practice guidelines so they can be meaningful during the compressed time frame of a pandemic. A good example of the natural tension that exists between methodologic purity and the clinical relevance of COVID-19 – associated guidelines lies with the 2021 American Society of Hematology (ASH) Guidelines on the use of anticoagulation in patients with COVID-19 who are being discharged from the hospital (Table 1). 1 The guideline authors issued a conditional recommendation against the use of outpatient anticoagulant prophylaxis for patients with COVID-19 who are being discharged from the hospital. 1 However, as the authors themselves suggest, the overall low quality of evidence on the topic of post-discharge thromboprophylaxis for hospitalized patients with COVID-19 requires careful interpretation of and judgment regarding direct evidence in this population and indirect evidence from hospitalized medically ill popula-tions without COVID-19. It is here that the authors ’ interpretations are subject to some bias or are not entirely based on a holistic or complete interpretation of the available clinical data. Importantly, 3 main issues stand out: (1) de fi nition of the relevant population of hospitalized patients with COVID-19