Optimising cohort data in Europe

to study relevant categories. This allows to solve privacy challenges related to the handling of real values (as real values are harmonised) and to provide an informational basis for research in the planning phase. y y Sustainability of data infrastructure: To use federated infrastructure or mixed infrastructure types in combination with cloud interfaces. y y Metadata: Mechanisms encouraging researchers to engage in detailed metadata description and documentation should be in place. The definitions of the quantity of interest should be included in the metadata. References Banerjee S, Bishop TRP. dsSynthetic: synthetic data generation for the DataSHIELD federated analysis system. BMC Research Notes 2022;15(230). https://doi. org/10.1186/s13104-022-06111-2 Borisov N, Suntsova M, Sorokin M, Garazha A, Kovalchuk O, Aliper A, et al. Data aggregation at the level of molecular pathways improves stability of experimental transcriptomic and proteomic data. Cell Cycle 2017;16(19):1810-1823. https:// doi.org/10.1080/15384101.2017.1361068. Burke DL, Ensor J, Riley RD. Meta-analysis using individual participant data: one-stage and two-stage approaches, and why they may differ. Statistics in Medicine 2017;36(5):855-875. https://doi.org/10.1002/sim.7141 Chandler RK, Kahana SY, Fletcher B, Jones D, Finger MS, Aklin WM, et al. Data collection and harmonization in HIV research: the seek, test, treat, and retain initiative at the National Institute on Drug Abuse. American Journal of Public Health 2015;105(12):2416-2422. https://doi.org/10.2105/AJPH.2015.302788 Devriendt T, Borry P, Shabani M. Factors that influence data sharing through data sharing platforms: A qualitative study on the views and experiences of cohort holders and platform developers. PLoS One 2021;16(7):e0254202. https://doi.org/10.1371/ journal.pone.0254202. Do NV, Barnhill R, Heermann-Do KA, Salzman KL, Gimbel RW. The military health system's personal health record pilot with Microsoft HealthVault and Google Health. Journal of the American Medical Informatics Association 2011;18(2):118-124. https://doi.org/10.1136/jamia.2010.004671 Donegan S, Williams L, Dias S, Tudur-Smith C, Welton N. Exploring Treatment by Covariate Interactions Using Subgroup Analysis and Meta-Regression in Cochrane Reviews: A Review of Recent Practice. PLOS ONE 2015;10(6): e0128804. https://doi. org/10.1371/journal.pone.0128804 Dubrow JK, Tomescu-Dubrow I. The rise of cross-national survey data harmonization in the social sciences: emergence of an interdisciplinary methodological field. Quality & Quantity 2016;50(4):1449-1467. https://doi.org/10.1007/s11135 015-0215-z