Background and purpose: In 2010, a multidisciplinary research group proposed a consensus term and definition for the complication of delayed cerebral ischaemia (DCI) following aneurysmal subarachnoid haemorrhage (SAH). We assessed the use of this term and its definition as an endpoint in observational studies and clinical trials. Methods: Firstly, we performed a MEDLINE abstract search from Jan 2008 to Dec 2017 for observational cohort studies and clinical trials to investigate the used terminology over the years. Next, we studied trends in citations of the original paper citing the consensus definitions since publication in 2010. Results: The number of publications citing the 2010 consensus definitions has steadily increased from 18 in 2011 to 54 in 2017. Between 2010 and 2017, 527 papers were published with delayed cerebral ischemia, or another term to describe the same complication, as an endpoint. However, the term delayed cerebral ischemia was used only in 131/527 (25%) of papers and only 14/81 (17%) of clinical trials/cohort studies published in 2017 cited the consensus definitions when outlining study endpoints. Conclusions: Despite publication of consensus terminology and definitions for DCI in 2010, the majority of cohort studies and clinical trials in patients with SAH are not using these. Researchers and editors should be reminded of the importance of using these consensus terminology and definitions in future studies, which will promote the comparability of results between studies, understand the true impact of an intervention, aggregate results in meta- analyses, and construct guidelines with a high level of evidence.