On the relevance of the Impact Factor and other factors

Intra-Specialty Citation Pattern in Radiology and Gastroenterology/Hepatology Journals: A Cross-Specialty Comparison

Objectives: To investigate intra-specialty citation patterns of radiology articles, compared with another medical specialty: gastroenterology/hepatology. Methods: Four radiology journals (Radiology, European Radiology, Diagnostic and Interventional Imaging, Canadian Association of Radiologists Journal) and four gastroenterology/hepatology journals (Journal of Hepatology, Journal of Gastroenterology, World Journal of Gastroenterology, Journal of Clinical Gastroenterology) with similar Web of Science in-category 2020 IF ranking were selected. The original research, review, letter, and editorial articles published in these journals in 2021 were identified. The average number of intra-specialty citations per article (intra-specialty citation count) and percentage of intra-specialty citations out of total citations per article (intra-specialty citation rate) were compared between radiology and gastroenterology/hepatology articles using Student's t-test. Results: The radiology articles demonstrated a lower total citation count per article (radiology: 29.7 ± .4 (mean ± SEM), n = 2063; gastroenterology/hepatology: 50.1 ± 1.4, n = 1335). The intra-specialty citation count was also lower in radiology articles than gastroenterology/hepatology articles (radiology: 12.9 ± .2, gastroenterology/hepatology: 19.6 ± .7; P < .001), both overall and in all article types. Additionally, the overall intra-specialty citation rate was not significantly different between the two specialties (radiology: 48.8% ± .5%; gastroenterology/hepatology: 47.1 ± .8%; P = .057), although the intra-specialty citation rates were higher in radiology original research and editorial article types. Conclusions: The significantly lower per-article intra-specialty citation counts in all radiology article types, a measurement that directly links to specialty IFs, may contribute to the lower impact factors of radiology journals compared with gastroenterology/hepatology ones.

Is quality and completeness of reporting of systematic reviews and meta-analyses published in high impact radiology journals associated with citation rates?

Purpose

The purpose of this study is to determine whether study quality and completeness of reporting of systematic reviews (SR) and meta-analyses (MA) published in high impact factor (IF) radiology journals is associated with citation rates.

Methods

All SR and MA published in English between Jan 2007–Dec 2011, in radiology journals with an IF >2.75, were identified on Ovid MEDLINE. The Assessing the Methodologic Quality of Systematic Reviews (AMSTAR) checklist for study quality, and the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) checklist for study completeness, was applied to each SR & MA. Each SR & MA was then searched in Google Scholar to yield a citation rate. Spearman correlation coefficients were used to assess the relationship between AMSTAR and PRISMA results with citation rate. Multivariate analyses were performed to account for the effect of journal IF and journal 5-year IF on correlation with citation rate. Values were reported as medians with interquartile range (IQR) provided.

Results

129 studies from 11 journals were included (50 SR and 79 MA). Median AMSTAR result was 8.0/11 (IQR: 5–9) and median PRISMA result was 23.0/27 (IQR: 21–25). The median citation rate for SR & MA was 0.73 citations/month post-publication (IQR: 0.40–1.17). There was a positive correlation between both AMSTAR and PRISMA results and SR & MA citation rate; ρ=0.323 (P=0.0002) and ρ=0.327 (P=0.0002) respectively. Positive correlation persisted for AMSTAR and PRISMA results after journal IF was partialed out; ρ=0.243 (P=0.006) and ρ=0.256 (P=0.004), and after journal 5-year IF was partialed out; ρ=0.235 (P=0.008) and ρ=0.243 (P=0.006) respectively.

Conclusion

There is a positive correlation between the quality and the completeness of a reported SR or MA with citation rate which persists when adjusted for journal IF and journal 5-year IF.