Selective Citation Practices in Imaging Research: Are Diagnostic Accuracy Studies With Positive Titles and...

OBJECTIVE. The purpose of this study was to examine the existence of selective citation practices in the imaging literature by assessing whether diagnostic accuracy studies with positive titles or conclusions are cited more frequently than those with negative (or neutral) titles or conclusions. MATERIALS AND METHODS. MEDLINE was searched for meta-analyses of diagnostic accuracy studies published in imaging journals from January 2005 to April 2016. Primary studies from the meta-analyses were screened for eligibility. Titles and conclusions were classified independently in duplicate. A negative binomial regression analysis controlling for several confounding variables was performed to obtain regression coefficients; p values were obtained via likelihood ratio testing. RESULTS. A total of 995 primary studies were included. Fifty-one titles (5.1%) and 782 conclusions (78.6%) were positive or positive with qualifiers; 942 titles (94.7%) and 127 conclusions (12.8%) were neutral; and two titles (0.02%) and 86 conclusions (8.6%) were negative. Studies with positive, neutral, and negative titles were cited a mean of 0.66, 0.50, and 0.06 times per month. Studies with positive, neutral, and negative conclusions were cited a mean of 0.54, 0.42, and 0.34 times per month. Regression coefficients were 1.10 (95% CI, -0.08 to 2.20) and 0.91 (95% CI, -0.27 to 2.00) for positive and neutral titles, relative to negative titles. Regression coefficients were 0.19 (95% CI, 0.03-0.35) and 0.08 (95% CI, -0.12 to 0.27) for positive and neutral conclusions, relative to negative conclusions. Title and conclusion positivity demonstrated positive association with citation rate (p = 0.031 for both). CONCLUSION. Studies with positive titles or conclusions are cited more frequently in imaging diagnostic accuracy literature. This difference may contribute to overestimation of the accuracy of a test and, consequently, suboptimal patient outcomes.