[Good Practice Data Linkage].

Individual data linkage of different data sources for research purposes is being increasingly used in Germany in recent years. However, generally accepted methodological guidance is missing. The aim of this article is to define such methodological standards for research projects. Another aim is to provide readers with a checklist for critical appraisal of research proposals and articles. Since 2016, an expert panel of members of different German scientific societies have worked together and developed 7 guidelines with a total of 27 practical recommendations. These recommendations include (1) research aims, questions, data sources and resources, (2) infrastructure and data flow, (3) data privacy, (4) ethics, (5) key variables and type of linkage, (6) data validation/quality assurance and (7) long-term use for future research questions. The authors provide a rationale for each recommendation. Future revisions will include any new developments in science and data privacy.