OBJECTIVES: PROQOLID was developed in 2002 to provide researchers involved in health care evaluation with a comprehensive and unique source of information on clinical outcomes assessments (COAs) available on Internet. In 2012, a review of the database (Emery et al. Qual Life Res. 2012;21:55) revealed considerable improvements. The objective of this study is to review the evolution of content, structure, and functionalities of PROQOLID since 2012. METHODS: The archives of PROQOLID were searched to retrieve the information gathered in 2012 and to compare its content and structure of May 25 2016. RESULTS: The April 2012 database included 714 instruments (100 generic/614 specific). Instruments specific to nervous system diseases were the most frequent (141). The structure had eight categories: contact, conditions of uses, copy of the questionnaire, translations available, descriptive information, content validity documentation, measurement properties, and references. By comparison, the May 2016 database includes 1243 instruments (74% increase with 152 generic and 1091 specific), with an increase of almost 130 instruments each year. Instruments specific to nervous system diseases are still the most frequent (n=221). In terms of structure, changes have been paramount. The information displayed for each instrument is categorized into 16 categories (seven in the free access level and nine in the member access level). Users have also access to all instruments distributed by Mapi Research Trust with the addition of online distribution services for academics. Since March 1 2016, PROQOLID has been integrated in an online platform, ePROVIDE™, which allows cross-searches with other databases such as PROLABELS and PROINSIGHT. The migration process has involved new designs and new connection and subscription modes. CONCLUSIONS: In four years, the PROQOLID database has considerably evolved in content and structure. The migration to ePROVIDE™ offers a range of information and services adapted to the evolution of the COA field.