The document "Registries for Evaluating Patient Outcomes: A User’s Guide" is a comprehensive resource for planning, developing, maintaining, and evaluating registries designed to collect data on patient outcomes. This fourth edition, prepared by the Agency for Healthcare Research and Quality (AHRQ), updates and expands on previous editions, incorporating new methodological and technological advances. The guide is structured into four main sections: Creating Registries, Legal and Ethical Considerations for Registries, Operating Registries, and Evaluating Registries. Each section covers key areas such as registry design, data elements, data sources, ethical considerations, informed consent, governance, participant recruitment, data quality assurance, adverse event detection, and data analysis and interpretation. The guide emphasizes the importance of good registry practices, including addressing potential biases and ensuring data integrity. It also provides practical advice on how to evaluate the quality of registries and their contributions to evidence development, design, operations, and evaluation. The document is intended to support stakeholders from various sectors in making informed decisions about the design, implementation, and use of patient registries.The document "Registries for Evaluating Patient Outcomes: A User’s Guide" is a comprehensive resource for planning, developing, maintaining, and evaluating registries designed to collect data on patient outcomes. This fourth edition, prepared by the Agency for Healthcare Research and Quality (AHRQ), updates and expands on previous editions, incorporating new methodological and technological advances. The guide is structured into four main sections: Creating Registries, Legal and Ethical Considerations for Registries, Operating Registries, and Evaluating Registries. Each section covers key areas such as registry design, data elements, data sources, ethical considerations, informed consent, governance, participant recruitment, data quality assurance, adverse event detection, and data analysis and interpretation. The guide emphasizes the importance of good registry practices, including addressing potential biases and ensuring data integrity. It also provides practical advice on how to evaluate the quality of registries and their contributions to evidence development, design, operations, and evaluation. The document is intended to support stakeholders from various sectors in making informed decisions about the design, implementation, and use of patient registries.