We thank Dr Faillie for his letter 1. We also deliberated at length about the exact definition of bias in our study.
The indications for the prescription of NSAIDs are broad and, unfortunately, data about the indication for use in our study were not available. Therefore, we could not ascertain whether all NSAID prescriptions in our study were to treat symptoms that typically precede a spontaneous abortion or to treat other symptoms. As such, protopathic bias may not explain all NSAIDs dispensations.
Although we chose to use the term ‘indication bias’, we believe that both definitions are applicable to the presented bias.
Reference
- Faillie J-L. Indication bias or protopathic bias? Br J Clin Pharmacol. 2015;80:779–80. doi: 10.1111/bcp.12705. [DOI] [PMC free article] [PubMed] [Google Scholar]