Open access route and citation impact in orthopaedic research: A comparison of Gold/hybrid, Green, and Bronze open access within ten high-impact subscription-based journals

Open access (OA) publishing has expanded access to research, but citation patterns may differ across OA routes. We examined the association between OA route and citation rate within ten high-impact, predominantly subscription-based orthopaedic journals, analysing 24,115 articles published from 2014 to 2019. Journals in which more than 95% of articles were OA were excluded by design; fully OA journals were therefore not represented, and every Gold OA article in this corpus was published as hybrid OA within a subscription journal (hereafter Gold/hybrid OA). Articles were classified as Gold/hybrid OA, Green OA, Bronze OA, or Closed Access using Web of Science OA indicators. Results are reported in three layers: unadjusted descriptive comparisons, a primary adjusted analysis, andsensitivity analyses. The primary analysis used an entropy-balanced negative binomial generalized linear mixed model adjusting for publication year, document type, author count, and journal influence, with journal-level random effects. Most articles were Closed Access (78.5%), followed by Green OA (9.1%), Bronze OA (8.7%), and Gold/hybrid OA (3.8%). In the primary analysis, Gold/hybrid OA and Green OA had higher citation rates than Closed Access (rate ratio 1.41, 95% CI 1.30–1.54; and 1.35, 95% CI 1.28–1.43), and did not differ from each other (1.04, 95% CI 0.95–1.15). Citation rates varied by publication year: Gold/hybrid OA had the highest predicted rate in recent cohorts and Green OA in older cohorts with longer follow-up. Bronze OA had the lowest unadjusted citation counts, largely because it was enriched for lower-cited document types. The higher citation rates for Gold/hybrid and Green OA persisted across all sensitivity analyses. Within subscription-based orthopaedic journals, OA routes are not interchangeable; these findings do not extend to fully OA journals.