Favorable and publicly funded studies are more likely to be published: a systematic review and meta-analysis.

OBJECTIVES

The aim of this study was to identify and quantify the characteristics of studies associated with the likelihood of publication.

STUDY DESIGN AND SETTING

We searched for manuscripts that tracked cohorts of clinical studies ("cohorts") that from launch to publication. We explored the association of study characteristics with the probability of publication via traditional meta-analyses and meta-regression using random effects models.

RESULTS

The literature review identified 85 cohorts of studies that met our inclusion criteria. The probability of publication was significantly higher for studies whose characteristics were favorable (odds ratio [OR] = 2.04; 95% confidence interval [CI]: 1.62, 2.57) or statistically significant (OR = 2.07; 95% CI: 1.52, 2.81), had a multicenter design (OR = 1.32; 95% CI: 1.16, 1.45), and were of later regulatory phase (3/4 vs. 1/2, OR = 1.34; 95% CI: 1.14, 1.49). Industry funding was modestly associated with lower (OR = 0.81; 95% CI: 0.67, 0.99) probability of publication. An exploratory analysis of effect modification revealed that the effect of the study characteristic "favorable results" on likelihood for publication was stronger for industry-funded studies.

CONCLUSION

The study characteristics of favorable and significant results were associated with greater probability of publication.