Objective To evaluate the current status of compliance with animal experiment reporting guidelines in medical research papers published in Chinese and to enhance the transparency of medical research reporting.

Methods Using a predefined literature search strategy, we conducted searches in the China National Knowledge Infrastructure (CNKI) database for literature published in 2019 and 2022 in journals indexed in A Guide to the Core Journals of China published by Peking University Library. We focused on 22 pieces of key information required in the ARRIVE Guidelines 2.0. These pieces of information concerned 6 items of the ARRIVE Essential 10 Items, including study design, sample size, randomization, statistical methods, and experimental animals, and 3 items of the ARRIVE Recommended Set, including abstract, ethical statement, and declaration of interests. We conducted statistical analysis of the reporting rates of the key information in the research publications included in the study.

Results A total of 4818 research papers were included in the analysis, and none comprehensively reported all 22 pieces of information investigated in the study. Most of the research papers published in 2019 and 2022 reported information on the control groups, with the reporting rate for the respective years being 99.8% (2461/2467) and 99.7% (2343/2351). Although the sample size reporting rates were 79.2% (1954/2467) for research papers published in 2019 and 77.2% (1815/2351) for those published in 2022, none described the method and rationale of sample size calculation. The reporting rates of randomisation and blinding methods were approximately 20% and 1%, respectively. The reporting of statistical methods increased slightly from 91.8% in 2019 to 96.0% in 2022. The reporting of information on the experimental animals showed mixed trends for 2019 and 2022, including the provenance of animals (93.8% vs. 93.7%, P > 0.05), strains and substrains (99.1% vs. 99.2%, P = 0.514), sex (94.1% vs. 92.7%, P = 0.044), age (58.1% vs. 70.6%, P < 0.001), weight (84.4% vs. 81.9%, P = 0.020), and health status (66.0% vs. 75.5%, P < 0.001). Research papers published in both 2019 and 2022 had relatively low rates of reporting animal ethics review (15.8% vs. 38.9%) and animal ethics principles adhered to (9.8% vs. 21.3%), declaration of interests (2.3% vs. 10.6%), and accurate summaries of animal-related information in the abstracts (9.16% vs. 8.13%). In particular, the reporting rate of the animal ethics statement and the declaration of interests increased significantly high in 2022 compared to that in 2019 (P < 0.001).

Conclusions Since ARRIVE Guidelines 2.0 was released, transparency in the reporting of most of the ARRIVE checklist items of interest in this study has improved significantly. However, the reporting of randomization, blinding, ethical statement, and declaration of interests still need further improvement and should be prioritized for future efforts.