OBJECTIVES: As defined by the FDA, a Clinical Outcome Assessment (COA) directly or indirectly measures how patients feel or function and can be used to determine whether or not a drug has demonstrated to provide a treatment benefit. There are four types of COAs: patient-reported (PRO), observer-reported (ObsRO), clinician-reported (ClinRO), and performance outcomes (PerfO). The aim of this research is to create an online database of published regulatory recommendations concerning the use of COAs to determine treatment benefit and to inform drug approval and health technology assessment (HTA) review. METHODS: All clinical guidelines published from 1977 to 2014 by North American regulatory authorities (FDA and Health Canada), the European Union (EMA), and NICE, were retrieved on the corresponding websites and reviewed. The information was categorized as follows: guideline title, date of publication, guideline status (“draft” or “final/adopted”), therapeutic area and indication based on ICD -10 classification, guideline purpose(s), and for each COA, the concept of interest and context of use (e.g., targeted patient population, endpoint positioning and study design). RESULTS: For the EMA, we reviewed 110 scientific guidelines representing 62 therapeutic indications, of which approximately more than half recommend COA endpoints. For the FDA, we analyzed 86 guidance representing 56 therapeutic indications, of which almost 60% recommend COA endpoints. For Health Canada, five guidance representing five therapeutic indications were retrieved. The 96 recommendations published by the NICE correspond to 75 therapeutic indications, and are currently under review. CONCLUSIONS: This project will be a unique source of centralized information about how COAs are recommended by regulatory authorities in drug development and HTA review. It will be useful to observe the current trends in COAs recommended, and to integrate them as early as possible in the product development. The database will be available online in an independent website, with access by subscription.