Case definitions play a large role in reported case numbers. China saw anywhere from 3 to 7 fold increases in the proportion of detected cases with each update to the national COVID-19 case definition guidelines. Experts urge that this variable be taken into account when making further models.

A case series of almost 200 COVID-19 patients found that the frequency of pulmonary embolism in infected patients is 2 times higher than that found during the control period.
Utmost caution is recommended for cryopreserving sperm, which has been found to have low risk of significant virus shedding but there is suggestion that may not be an acceptable risk.
A pilot cohort study with Baricitinib therapy for COVID-19 patients found significant improvement of clinical and respiratory parameters within two weeks.