Literature Search Approaches in an Era of Increasing Publication Volume

OBJECTIVES: Literature reviews are a key part of the drug development process used in early exploration of unmet needs through regulatory submission and post-marketing activities. The amount of literature published each year has increased substantially over the past decade. Previously, focusing on the most recent literature could reduce scope while still identifying the most relevant studies, but the increase in publications has reduced the utility of publication year limits alone. This research was undertaken to explore ways to reduce the time and cost burden of literature reviews.

METHODS: Literature searches were conducted in Embase to identify real world studies reporting on treatment patterns of disease-modifying therapy in multiple sclerosis (MS). A search for real-world studies in MS, including filters for removing irrelevant publication types, was conducted before applying additional filters for publication year, interventions, and outcomes of interest. Conference abstracts were removed from all searches. Hours to screen citations at the title/abstract level were estimated using a rate of 45 abstracts per hour.

RESULTS: Over 16,000 citations were identified by the search for real-world studies in MS, of which 74% were published in the last 10 years (530 person-hours for dual screening) and 48% were published in the last 5 years (344 person-hours for dual screening). The number of studies (person-hours to dual screen) identified in a search of the last 10 years was substantially reduced by applying filters for interventions of interest (3,464 [154]), outcomes of interest (1,623 [72]), or both (577 [27]). Further reductions in scope are possible based on review methodology.

CONCLUSIONS: Increased publication volume has increased the time and budget burden of literature reviews. Defining specific research questions a priori and choosing review methodology appropriate to the goal of the review allow for a more focused search and screening process and a reduction in the scope to complete the review.