IntroductionIn recent years, various policies have been implemented to improve the quality of maternity care in the Netherlands. To gain insight into their effects, we initiated a nationwide data-infrastructure. In this workshop, we describe the data-infrastructure, discuss how the data-infrastructure (can) contribute(s) to the evaluation of the effects of policies, and explore the opportunities and limitations thereof in an interactive discussion. Two cases serve as examples to discuss the use of the data-infrastructure to evaluate integrated maternity care policies: 1) experimental implementation of bundled payments for maternity care, 2) monitoring the nationwide ‘first 1000 days approach’.BackgroundIn the Netherlands, multiple registries containing nationwide observational data are available. We linked claims data (2011-2018) with data on health outcomes and quality of maternity care (2000-2018). In total, this combined dataset contains over 3 million pregnancies. We enriched this dataset further by data from Statistics Netherlands among which educational level, household income, debts, work status and household composition. We were also able to link parents to their children based on Statistics Netherlands. So far, this nationwide data-infrastructure was used to evaluate the first effects of the experimental implementation of bundled payments in maternity care and to identify baseline results regarding the ‘first 1000 days approach’.Aim and objectivesWe aim to provide insight into the methodology used to integrate multiple observational datasets into an inclusive data-infrastructure and we aim to clarify the use of this data-infrastructure to evaluate integrated maternity care policies by providing two exemplifying cases. During the interactive discussion, we aim to discuss opportunities and limitations of such data for the purpose of policy evaluations including their suitability for causal inference, and stimulate discussion of possible other applications of the data-infrastructure.Target ...