Letter to the Editor: "Transdermal vs Oral Estrogen Therapy and Venous Thromboembolism: Upgrade the Level of Evidence" by.

Scarabin PY, et meta-analysis by Mohammed et al (1) confirms the safety advantage of transdermal vs oral estrogens with respect to the risk of venous thromboembolism (VTE). Surprisingly, the quality of evidence is described as very low (see Table 4 in the report). We believe that this quality rating based on “the observational nature of the studies and inconsistency of results” is not appropriate...