Recent Outcomes Research in Helicopter Emergency Medical Services: A Scoping Review of Publication-Year 2024...

This scoping review is an annual update of helicopter emergency medical services (HEMS) outcomes literature added to the HEMS outcomes assessment research database (HOARD). HOARD is maintained by the critical care transport collaborative outcomes research effort (CCT CORE) and is updated each year with the previous calendar year's studies assessing whether HEMS use alters patient-centered outcomes.

Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Scoping Review (PRISMA-ScR) guidelines, we used multiple reviewers of records retrieved from multiple medical and gray literature sources: Medline (PubMed), EMBASE, Scopus, CINAHL, and Google Scholar. Eligible for review was HEMS vs. ground EMS outcomes studies either published or appearing in preprint databases during calendar year 2024. HOARD excludes case reports and review articles (unless they provide a new calculation of effect estimate). We assessed articles for subject matter (trauma vs non-trauma), journal impact factor (JIF), and geographic region of the study's correspondence author. Categorical analyses comparing 2024 studies with HOARD studies from 2023 were executed with Pearson's chi-square or Fisher's exact test, and we also calculated risk ratio with its 95% confidence interval. Non-normal JIF data were described using median and interquartile range and analyzed using rank sum testing. Nonparametric trend testing evaluated the last decade's evidence using Cochrane-Armitage (dichotomous) or Cuzick (JIF) testing.

Of an initial records of N = 5,179 (74 of which were reviewed as full text), we identified 21 studies for addition to HOARD. Longitudinal analysis revealed a significant (P < .001) annual trend toward increasing proportions of studies focusing on non-trauma; 2024 was the first time in a decade that the more than half of the year's outcomes studies focused on non-trauma. There was no indication of trend involving the proportion of studies emanating from the USA (P = .821) or from the combined countries of USA and Europe (P = .566). The 2024 JIF had a median of 2.11 and interquartile range of 1.25 to 2.60. There was no suggestion (P = .919) of longitudinal JIF trend in the past decade.

This scoping review provides information on 21 HEMS outcomes studies new to the evidence base in 2024. The HOARD database, freely available, has been updated with these studies.