3.4 Sources of ongoing clinical trials

Ongoing trials may have limited use as a means of identifying studies relevant to systematic reviews, but may be important so that when a review is later updated, these studies can be assessed for possible inclusion. Several initiatives have been taken recently to register ongoing trials:

• International Clinical Trials Registry Platform (ICTRP)
• EU Clinical Trials Register
• ClinicalTrials.gov
• Current Controlled Trials
• More clinical trials register are listed on the KCE library catalogue