Background: In the last few years, a high number of new drugs for hospital use have been incorporated in therapeutics, generally intended to treat severe pathologies and associated to high costs of treatment. Often, these drugs are authorized with limited information, and clinical uncertainties remain regarding their actual clinical utility. Therefore, actions are needed to guarantee efficiency and equity in drug access, and to watch over the sustainability of the system. To that purpose, the collection of information from routine clinical practice, or real world data (RWD), is useful and necessary. Since 2012, the Catalan Integrated Healthcare System (SISCAT as per Catalan spelling) holds the Registry of patients and treatments of hospital outpatient drugs (RPT-MHDA, as per Catalan spelling), that gathers clinical and pharmacological information on all treatments and patients receiving hospital outpatient drugs funded by the Catalan Health Service (CatSalut). After several years of deployment, the maturity of the registry opens the opportunity to advance in the use of its data to support management of access and rational use of MHDA. Objective: To assess if obtaining and analysing RPT-MHDA data on drug utilization and health outcomes in real life is useful to support decision making on access management and to promote rational use of new MHDA medicines, providing added value. Methods: The data available in the RPT-MHDA was described and its quality analysed. Procedures for writing reports on health outcomes and to return of the information to professionals were standardised, and their implementation appraised. Indicators of rational use and examples of inclusion of RPT-MHDA data in the decision making process were defined and described. The added value of the RPT-MHDA as subjectively perceived by a sample of healthcare professionals was analysed, and areas of improvement and development were identified. Results: RPT-MHDA includes data on more than 230,000 treatments in more than 580 different indications with more than 180 different drugs for more than 148,000 patients. A sample data validation has concluded that 85% of the items checked were traceable in clinical records and correct, and an Integral Plan of Quality has been proposed. Standard procedures for report writing have been defined and appraised in 4 reports of health outcomes, showing an attainment of 75% of the standard. Similarly, standard procedures for information return to healthcare professionals have been defined and appraised by a sample of professionals, who have rated the reports positively highlighting their utility for improving clinical management and efficiency of new medicines. Up to 2019, 4 indicators are available that use RPT-MHDA data to assess quality and rational use of the MHDA, with a high degree of compliance of the objectives. Data from RPT-MHDA has been used in decision making for almost 100 interventions, including: estimation of the number of patients and budget impact, reassessment of drugs, drug utilization in specific populations, pharmacological tariffs, financial risk sharing agreements, or payment for health outcomes, amongst others. Different stakeholders implicated in the process of the RPT-MHDA have identified some weaknesses, threats, strengths and opportunities, and its added value. Areas of improvement have been identified, some already implemented and others to be developed, such as automated data capture, inclusion of patient reported outcomes, enhanced communication and transparency of the made actions. Conclusions: The use of RWD from RPT-MHDA is a valuable tool to support access management and to promote rational use of new drugs, which can contribute to improve patient care and the efficiency and sustainability of the health public system in Catalonia.