Journal Initiatives to Enhance Preclinical Research: Analyses of Stroke, Nature Medicine, Science Translational Medicine

Background and Purpose- Preclinical research using animals often informs clinical trials. However, its value is dependent on its scientific validity and reproducibility, which are, in turn, dependent on rigorous study design and reporting. In 2011, introduced a Basic Science Checklist to enhance the reporting and methodology of its preclinical studies. Except for and journals, few others have implemented similar initiatives. We sought to estimate the impact of these journal interventions on the quality of their published reports. Methods- All articles published in , , and over 9 to 18 years and in 2 control journals without analogous interventions over a corresponding 11.5 years were reviewed to identify reports of experiments in nonhuman mammals with proposed clinical relevance. The effect of journal interventions on the reporting and use of key study design elements was estimated via interrupted time-series analyses. Results- Of 33 009 articles screened, 4162 studies met inclusion criteria. In the 3.5 to 12 years preceding each journal's intervention, the proportions of studies reporting and using key study design elements were stable except for blinding in and randomization in , which were both increasing. Post-intervention, abrupt and often marked increases were seen in the reporting of randomization status (level change: +17% to +44%, ≤0.005), blinding (level change: +20% to +40%, ≤0.008), and sample size estimation (level change: 0% to +40%, ≤0.002 in 2 journals). Significant but more modest improvements in the use of these study design elements were also observed. These improvements were not seen in control journals. Conclusions- Journal interventions such as 's author submission checklist can meaningfully improve the quality of published preclinical research and should be considered to enhance study transparency and design. However, such interventions are alone insufficient to fully address widespread shortcomings in preclinical research practices.