ABSTRACT
Hormone replacement therapy (HRT), in contrast to estrogen-containing oral contraceptive pills which have long been recognized to carry an excess risk of venous thromboembolism (VTE)192,216, was not217-222 until recently considered to be associated with such a risk. Although there had been two small descriptive studies that suggested a link, this was not borne out by a case-control study217. Thus, clinicians were reassured. However, many of the initial studies assessing the risk had limited statistical power or methodological limitations. Factors such as a lack of objective diagnosis coupled with less reliable diagnostic tools, potential patient selection bias
and the less widespread use of HRT are likely to have played a role in the failure to find an association.
