Commentary regarding recent Million Women Study critique and subsequent publicity.

摘要

The Million Women Study (MWS) was one of the major studies that raised concerns over the long-term safety of hormone replacement therapy (HRT). Shapiro et al. applied causal criteria, such as biases and biological plausibility, to assess the MWS findings. Their analysis highlighted several design flaws that would potentially have skewed the findings; the key criticisms of the MWS design were as follows: (1) Cancers detected within a few months of the study's start would have already been present when women were enrolled in the research, but these were not excluded from analysis; (2) Study participants were recruited from a breast screening programme. The invitation to the study could have led to higher numbers of cancers being detected (detection bias) by increasing the participation of HRT users already aware of breast problems.