Tweeting Bias in Diagnostic Test Accuracy Research: Does Title or Conclusion Positivity Influence Dissemination?

PURPOSE: To examine if tweeting bias exists within imaging literature by determining if diagnostic test accuracy (DTA) studies with positive titles or conclusions are tweeted more than non-positive studies. METHODS: DTA studies published between October 2011 to April 2016 were included. Positivity of titles and conclusions were assessed independently and in duplicate, with disagreements resolved by consensus. A negative binomial regression analysis controlling for confounding variables was performed to assess the relationship between title or conclusion positivity and tweets an article received in the 100 days post-publication. RESULTS: 354 DTA studies were included. Twenty-four (7%) titles and 300 (85%) conclusions were positive (or positive with qualifier); 1 (0.3%) title and 23 (7%) conclusions were negative; and 329 (93%) titles and 26 (7%) conclusions were neutral. Studies with positive, negative, and neutral titles received a mean of 0.38, 0.00, and 0.45 tweets per study; while those with positive, negative, and neutral conclusions received a mean of 0.44, 0.61, and 0.38 tweets per study. Regression coefficients were -0.05 (SE 0.46) for positive relative to non-positive titles, and -0.09 (SE 0.31) for positive relative to non-positive conclusions. The positivity of the title (P = 0.91) or conclusion (P = 0.76) was not significantly associated with the number of tweets an article received. CONCLUSIONS: The positivity of the title or conclusion for DTA studies does not influence the amount of tweets it receives suggesting that tweet bias is not present among imaging diagnostic accuracy studies. Study protocol available at https://osf.io/hdk2m/.

Reporting Bias in Imaging Diagnostic Test Accuracy Studies: Are Studies With Positive Conclusions or Titles Submitted and Published Faster?

OBJECTIVE: The purpose of this study is to evaluate whether imaging diagnostic test accuracy (DTA) studies with positive conclusions or titles have a shorter time to publication than those with nonpositive (i.e., negative or neutral) conclusions or titles. MATERIALS AND METHODS: We included primary imaging DTA studies from systematic reviews published in 2015. The conclusion and title of each study were extracted, and their positivity was classified independently in duplicate. The time from study completion to publication was extracted and calculated. A Cox regression model was used to evaluate associations of conclusion and title positivity with time to publication, with adjustment made for potentially confounding variables. RESULTS: A total of 774 imaging DTA studies were included; time from study completion to publication could be calculated for 516 studies. The median time from completion to publication was 18 months (interquartile range, 13-26 months) for the 413 studies with positive conclusions, 23 months (interquartile range, 16-33 months) for the 63 studies with neutral conclusions, and 25 months (interquartile range, 15-38 months) for the 40 studies with negative conclusions. A positive conclusion was associated with a shorter time from study completion to publication compared with a non-positive conclusion (hazard ratio, 1.31; 95% CI, 1.02-1.68). Of all included studies, 39 (5%) had positive titles, 731 (94%) had neutral titles, and 4 (< 1%) had negative titles. Positive titles were not significantly associated with a shorter time to study publication (hazard ratio, 1.12; 95% CI, 0.75-1.69). CONCLUSION: Positive conclusions (but not titles) were associated with a shorter time from study completion to publication. This finding may contribute to an overrepresentation of positive results in the imaging DTA literature.