Authors’ reply to the technical comment from Joelle Michaud and Goranka Tanackovic

We thank Drs Michaud and Tanackovic for their letter. The main objective of all care providers and researchers is to enhance safe prescription of contraception and we welcome scientific efforts to do so. The important genetic role in the development of venous thromboembolism is undisputed, leading to the reasonable hope of valuable personalised medicine tools. Drs Michaud and Tanackovic bring some clarification to the issues that we brought forward when suggesting caution in using Pill Protect®. However, even though the manufacturer is convinced of the scientific robustness of their tool, we are still left with uncertainties due to the lack of scientific publication for “business development reasons”. The design of the study, which appears to include multiple sources of patients, indirect estimations of absolute risks and several small validation efforts, is too complex for adequate understanding of this genetic tool currently. Most importantly, we would like to re-stress our belief that robust external validation of the algorithm is needed. As of today, we still feel that the use of Pill Protect® is somewhat precipitate, but we look forward to the scientific publication by the manufacturer in a peer-reviewed journal, in order to inform both care providers and patients of the scientific value and limitations of this tool.