Extended Data for "A theory-informed mixed-methods approach for early implementation assessment in complex intervention trials: a methodological development study".

Methodological materials accompanying the manuscript “A theory-informed mixed-methods approach for early implementation assessment in complex intervention trials: a methodological development study”. The record contains the materials developed for the identification, classification and selection of implementation outcomes and assessment items, the stakeholder-specific implementation questionnaires, and the qualitative interview and focus-group guides used in the study. These materials are provided as Extended Data to support transparency and reproducibility of the methodological approach described in the manuscript.