Determinants of journal impact factors in 'Nutrition and Dietetics'.

BACKGROUND AND AIM

The aim of this cross-sectional study was to analyse determinants of the 2023 impact factors (IFs) of journals within the field of 'Nutrition and Dietetics'.

METHODS

The Clarivate™ Journal Citation Reports™ website (https://jcr.clarivate.com/jcr/home) was searched on 9 January 2025 for journals with a 2023 IF (published in June 2024) ≥ 6.0 in the field of 'Nutrition and Dietetics'. Analysis was performed using GraphPad Prism software.

RESULTS

There were there were 84,040 citations in 2023 to 10,719 works published in 2021 and 2022 in the 12 journals with an IF ≥ 6.0. Median numbers of citations per output were lower than mean citations in all journals. This difference ranged from 0.55 to 3.97. Most outputs (47.5%-79.1 %) had 1-10 citations. The 1538 open access outputs were cited less frequently [mean (95 % CI) 6.98 (6.55-7.40)] than the 9181 subscription outputs [7.99 (7.81-8.16), P < 0.0001]. The 2063 reviews were cited more frequently [8.94 (8.45-9.43)] than the 8656 original articles [7.58 (7.42-7.74), P < 0.0001]. When the highest cited outputs from each journal were excluded, the fall in IFs ranged from 0 to 2.4. The was also the case when the two highest cited outputs were excluded (fall ranged from 0 to 2.7).

CONCLUSION

This comprehensive analysis of journal IFs has shown that although review articles increase IFs of journals, open access outputs do not. IFs can be distorted by 1 or 2 highly cited outputs and may not reflect the impact of the majority of outputs.