This study confirms that the OA advantage is a statistically significant, independent positive increase in citations, even when we control the independent contributions of many other salient variables (article age, journal impact factor, number of authors, number of pages, number of references cited, Review, Science, USA author).
Table 5 Predictors for retweeting political news articles Predictive variables Agree with article Disagree with article F1 numexposures 0.74∗∗∗ 0.83∗∗∗ F2 topic-interesting-me 0.16 1.23∗ F5 topic-interesting-followers 0.22 −0.36 F6 leaning-matched-followers −0.44∗ 1.55∗∗ F8 mutualfriend 0.14∗ 0.14∗
Firstly, two of the four explanatory variables representing article characteristics were found to contribute significantly to citation counts.
No significant relationships between year and any of the risk factor or early detection variables in article text were found; in contrast, significant patterns of coverage over time were detected for three UV behavior variables.
We created an excel spreadsheet and collected data on 20 variables per article, including: index test, author and year of publication, culture method, country of study, study HIV prevalence, sample size, specimen type, culture method, and numbers of true positive, true negative, false positive, and false negative.
Interactions of the PMC variable with article age and baseline performance variables were also included in the model to test whether the PMC effect was constant across the data set.
In three of the reviewed articles the authors applied an informal single imputation approach, substituting the missing values with values from surrogate variables (two articles) or with the median values calculated from the non-missing data for the covariates in the final model (one article).
The winds are variable, View Article By Miranda Carter By Amos Barshad By Doreen St. Félix By Jia Tolentino.
Meanwhile, to avoid spurious regression caused by the time variable, this article includes time trend in the model as well.
We also found that success in searches for terms was highly variable from article titles and abstracts or from inside the article text: some terms occur predominantly in the body text of an article and can thus only be located using a full-text PDF search (Table 1).
A supplementary logistic regression analysis based on the same set of variables for articles estimated that open access publishing reduced the expected odds of being cited by about 13% (odds ratio 0.87, 95% confidence interval 0.66 to 1.17; P=0.36, see supplementary table at http://hdl.handle.net/1813/11049), although this effect was not statistically significant.
