OBJECTIVES: Systematic literature reviews (SLRs) include recent conferences as grey-literature sources. Abstracts are routinely indexed in Embase but some might be unidentifiable if indexing is inadequate or delayed. To investigate this, we compared yields from Embase searches of ISPOR Europe congresses with hand-searching of the ISPOR and Value in Health (VH) websites, for records on COVID-19, prostate cancer and cystic fibrosis, representing highly, commonly and rarely reported topics, respectively.

METHODS: We searched Embase (via Ovid), VH (via Science Direct) and the ISPOR website for abstracts from ISPOR Europe 2020 and 2021, to compare the number of hits for the diseases of interest across these three platforms.

RESULTS: For cystic fibrosis, seven abstracts were identified in each platform. Embase and VH identified the same references, but these had two discrepancies compared to the ISPOR website. For prostate cancer, there were 30, 39 and 36 abstracts retrieved through searching Embase, VH and the ISPOR website, respectively. All the Embase hits were identified in the VH and ISPOR website searches. In addition to the three references in the VH search, there were another four discrepancies between the platforms when compared to the ISPOR website search.

For COVID-19, there were 231, 256 and 308 abstracts retrieved searching Embase, VH and the ISPOR website, respectively. There were 31 different references between Embase and VH. As the ISPOR website does not support exporting to a reference manager, duplicates across the searches for the different “COVID-19” terms were difficult to quantify and so comparison with the other platforms was not performed.

CONCLUSIONS: The findings demonstrate discrepancies in abstract retrieval between Embase, VH and ISPOR website for ISPOR Europe, and ideally several platforms should be searched for completeness. This assessment was only based on three diseases and further research is needed to include wider topics and other congresses.