Uptake of the core outcome set on polycystic ovary syndrome before and after its publication

STUDY QUESTION: Does the core outcome set (COS) on polycystic ovary syndrome (PCOS) impact the selection of research outcomes? SUMMARY ANSWER: Following the publication of the COS on PCOS, an increasing number of trials are reporting both the generic domain and body mass index; however, the uptake of this COS has not been as extensive as expected. WHAT IS KNOWN ALREADY: The COS on PCOS included 33 core outcomes in the following seven domains: the generic (3), metabolic (8), reproductive (7), pregnancy (10), psychological (3), oncological (1), and long-term (1). This was done to improve consistency in outcome selection and definition. However, thus far, no studies have investigated the effectiveness of this COS in the above-mentioned tasks. STUDY DESIGN, SIZE, DURATION: A methodological study based on the trial registries, including 395 eligible clinical trials registered between 1 January 2018 and 21 September 2022. PARTICIPANTS/MATERIALS, SETTING, METHODS: A total of 1258 registered clinical studies on PCOS were retrieved from the World Health Organization International Clinical Trials Registry Platform. Of those, 395 were selected according to the inclusion and exclusion criteria, and divided into two groups based on the publication date of the COS on PCOS (4 February 2020): pre-publication and post-publication. The practical uptake of this COS was explored after data collation, assessment, comparison of the uptake of core outcomes or domains before and after the publication of this COS, and correlation analysis between the domains. MAIN RESULTS AND THE ROLE OF CHANCE: There were 26 out of 33 core outcomes and five out of seven domains reported in the 395 trials. The highest uptake was observed for the reproductive domain and the reproductive hormonal profile (63.0% and 38.7%, respectively). After the publication of the COS on PCOS, the uptake of the generic domain and body mass index increased from 24.1% to 35.8% (P = 0.011) and 17.8% to 26.5% (P = 0.039), respectively. The total number of reported core outcomes in the generic domain met statistical significance (P = 0.012). Moreover, multivariable analyses still supported the above finding in the generic domain. Correlation analysis showed that most of the domains were positively correlated with each other. However, the pregnancy domain was negatively correlated with the metabolic domain. Reasons responsible for the unsatisfactory uptake may be the absence of specific definitions of core outcomes, as well as the lack of awareness among researchers regarding this COS. LIMITATIONS, REASONS FOR CAUTION: Due to the lack of standardized definition of outcomes, it was difficult to avoid some subjectivity in the process of consistency assessment. WIDER IMPLICATIONS OF THE FINDINGS: Two years after its publication, there was no substantial improvement in the uptake of the COS on PCOS. This suggests that this COS may require further revision, refinement, and promotion to improve the comparability of PCOS studies. STUDY FUNDING/COMPETING INTEREST(S): This work was funded by Beijing Municipal Health Science and Technology Achievements and Appropriate Technology Promotion Project (BHTPP2022069), and the special fund of Beijing Key Clinical Specialty Construction Project. The authors do not have conflicts of interest to declare. TRIAL REGISTRATION NUMBER: N/A.