A value of four was chosen because multiple studies on publication bias estimated the ratio of the probability of publishing studies showing statistically significant positive results to the probability of publishing other results as close to four.
Incorrect positive conclusions regarding carcinogenicity may also occur in reviews of multiple studies because of publication bias, which may selectively populate the literature only with "positive" findings.
Study multiple study guides.
When there were multiple reports of a same study, publication with the longest follow-up period or the largest event numbers was selected for estimation of pooled RRs, to avoid bias.
After abstraction of data from both sources, we compared the following study characteristics between the summary and publications: randomization (yes/no), blinding (single, double, or none as reported in the summary or publications), number of sites, number of patients enrolled, patient demographics (age, sex, race), and whether results from multiple studies were pooled into one publication.
Some publications reported on multiple studies with different patient populations and methods.
MycoDB contains data on plant productivity response to mycorrhizal fungi from 4,010 studies (from 438 unique publications) and is organized in a hierarchical fashion such that a single publication can contain multiple discrete experiments and a single experiment can contain multiple studies.
However, we know of no other publications since Spelman (1986) and later Spelman and Eck (1989) that have analyzed the cumulative distribution of offending across multiple studies.
Multiple studies show it.
Multiple studies bear this out.
