Sharing is caring? International Society of Pharmacoepidemiology review and recommendations for sharing of programming code

Purpose: There is increasing recognition of the importance of transparency and reproducibility in scientific research. This study aimed to quantify the extent to which programming code is publicly shared in pharmacoepidemiology, and to develop a set of recommendations on this topic. Methods: We conducted a literature review identifying all studies published in “Pharmacoepidemiology and Drug Safety” (PDS) between 2017 and 2022, Data was extracted on the frequency and types of programming code shared, and other key open science practices (clinical codelist sharing, data sharing, study pre-registration, and use of reporting guidelines). We developed six recommendations for investigators who choose to share to programming code and gathered feedback from members of the International Society of Pharmacoepidemiology (ISPE). Results: Programming code sharing by articles published in PDS ranged from 2.4% in 2017 to 13.4% in 2022. It was more prevalent among articles with a methodological focus, simulation studies, and papers which also shared record-level data. We recommend that reporting of open science practices, including code sharing, is standardised to enable continued monitoring. When sharing programming code, we recommend the use of permanent digital identifiers, appropriate licenses, and, where possible, adherence to good software practices around the provision of metadata and documentation, computational reproducibility, and data privacy. Conclusion: Programming code sharing is rare but increasing in pharmacoepidemiology studies published in Pharmacoepidemiology and Drug Safety. We recommend improved and consistent reporting of code sharing, and adherence to good programming practices in order to maximize the utility of code when this is shared.