Importance  Coronavirus disease 2019 (COVID-19) is an emerging infectious disease that was first reported in Wuhan, China, and has subsequently spread worldwide. Risk factors for the clinical outcomes of COVID-19 pneumonia have not yet been well delineated.

Conclusions and Relevance  Older age was associated with greater risk of development of ARDS and death likely owing to less rigorous immune response. Although high fever was associated with the development of ARDS, it was also associated with better outcomes among patients with ARDS. Moreover, treatment with methylprednisolone may be beneficial for patients who develop ARDS.

Как правильно переводить importance и relevance. Актуальность и значение? Значение и актуальность?

Importance - важность/актуальность исследования (т.к. в статье речь об исследовании)

Relevance - значимость, релевантность (соответствие цели исследования и полученных результатов)