Individual Research Behaviors and Research Funding Acquisition Across Fields and Career Periods: Regression Analysis.

Background: Acquiring external funding for academic research is a crucial element of researcher performance assessment. However, funding opportunities are often concentrated among a limited number of researchers, reinforcing existing structural inequalities. Under these conditions, it is important to clarify how individual researchers can improve their ability to secure external funding through their own actions and thereby build sustainable academic careers. In addition, fair faculty evaluation requires recognizing disciplinary differences in funding acquisition without assuming a normative research environment. Objective: This study aimed to examine whether research-related behaviors at different career stages contribute to variations in funding acquisition capability across research fields. Methods: We used funding data from Grant-in-Aid for Scientific Research, Japan's largest competitive research funding program, and classified 1152 professors according to their lifetime patterns of research funding acquisition. We also collected data on individual research-related behavioral characteristics, including supervisor prestige, authorship position, publication quality, collaborative research structure, and funding acquisition strategies, from publication records and administrative data, constructing a dataset of 804 researchers. By integrating these datasets, we conducted univariate and multivariate regression analyses to examine the factors associated with research funding acquisition. Results: Field-specific differences were observed in the upper range of funding levels and individual behaviors. High-funding recipients were found only in the field of basic and internal medicine. Univariate logistic regression analyses showed that early-career publication success (basic medicine: odds ratio [OR] 1.48, 95% CI 1.22-1.79; internal medicine: OR 1.34, 95% CI 1.06-1.69; and surgery: OR 1.70, 95% CI 1.28-2.27) and midcareer senior authorship were significantly associated with funding acquisition (basic medicine: OR 5.99, 95% CI 2.63-13.65; internal medicine: OR 3.17, 95% CI 1.16-8.70; and surgery: OR 9.79, 95% CI 3.26-29.43). In addition, supporting specific collaborators (surgery: OR 2.09, 95% CI 1.10-3.97) and the quality of publications during the first 12 years of a researcher's career were major determinants of success (surgery: OR 2.22, 95% CI 1.18-4.17). In multiple linear regression analyses with total funding as the outcome, the adjusted R² values were 0.576 for surgery, 0.890 for social medicine, and 0.738 for dentistry, indicating that the models accounted for many behavioral factors associated with funding acquisition. However, the model fit suggests that additional relevant factors may influence funding acquisition in basic medicine, internal medicine, and nursing. Conclusions: This study identified individual behaviors that influence Grant-in-Aid for Scientific Research funding acquisition across research fields. While organizational and academic structures have a significant impact, personal initiative during researchers' transition from peripheral to core roles becomes important, emphasizing strong relationship-building skills and outstanding publication records. As effective actions and their timing vary by field, individuals must consider their field characteristics and implement appropriate measures at suitable times.