Publication bias, time-lag bias, and place-of-publication bias in social intervention research: An exploratory study of 527 Swedish articles published between 1990-2019

Publication and related biases constitute serious threats to the validity of research synthesis. If research syntheses are based on a biased selection of the available research, there is an increased risk of producing misleading results. The purpose fo this study is to explore the extent of positive outcome bias, time-lag bias, and place-of-publication bias in published research on the effects of psychological, social, and behavioral interventions. The results are based on 527 Swedish outcome trials published in peer-reviewed journals between 1990 and 2019. We found no difference in the number of studies reporting significant compared to non-significant findings or in the number of studies reporting strong effect sizes in the published literature. We found no evidence of time-lag bias or place-of-publication bias in our results. The average reported effect size remained constant over time as did the proportion of studies reporting significant effects.

Automated summary

Publication and related biases pose significant threats to the validity of research synthesis, potentially leading to misleading results. This study examined the presence of positive outcome bias, time-lag bias, and place-of-publication bias in published research on psychological, social, and behavioral interventions. The results, based on 527 Swedish outcome trials from 1990 to 2019, showed no difference in the number of studies reporting significant versus non-significant findings or strong effect sizes. There was also no evidence of time-lag bias or place-of-publication bias. The average reported effect size and proportion of studies reporting significant effects remained consistent over time.