<p>Sample search strategy for MEDLINE.</p>

Among first authors, 675 (50.7%) were women, and 657 (49.3%) were men, indicating no gender difference. Among last authors, 486 (36.4%) were women, and 848 (63.6%) were men, with a statistically significant difference (χ² = 98.23, p < 0.001). Studies with women last authors had fewer listed co-authors than those with men (t = −3.63, p < 0.001; risk difference = −27.14%, 95% CI −32.50% to −21.77%).

In adjusted models, women’s last authorship was negatively associated with number of authors (adjusted odds ratio [aOR]=0.93, 95% CI 0.90–0.97). Publication year was associated with both women first (aOR=1.03, 95% CI 1.01–1.05) and last (aOR=1.05, 95% CI 1.02–1.07) authorship.</p> <p>Conclusions</p><p>Our findings highlight a gender disparity in last authorship positions, with men more often in these roles. The association between women last authorship position and smaller author teams may reflect differences in collaborative structure and access to leadership opportunities in larger-scale methodological research.

Addressing these disparities can help foster more inclusive research environments, especially within methodological research.</p></div>