Reporting quality of randomized controlled trial abstracts presented at the European Orthodontic Society Congress between 2015-2024: has there been an improvement over time?

Background: Throughout a trial report, clear and accurate reporting is essential. The aim of this study was to assess the reporting quality of RCT abstracts presented at the European Orthodontic Society (EOS) Congress between 2015-2024. Associations between reporting quality and abstract characteristics were explored.

Material and methods: All EOS Congress scientific abstracts published between 2015-2024 (2020 excluded) were included. Descriptive statistics and frequency distributions were calculated. Mean values for adequate reporting per CONSORT item and sum score were calculated. On an exploratory basis, univariable linear regression between summary score and abstract characteristics was undertaken.

Results: 139 RCT congress abstracts were analysed. The most frequent years of RCT abstract presentation were 2018 (14.4%) and 2023 (19.4%). RCT abstracts were more likely to be poster types (62.6%), with corresponding authors based in Europe (77.7%), single centre (64.7%) and reporting a non-significant result for the primary outcome (54.0%). The mean overall total quality reporting score was 17.6 (SD 5.6, min 15 and max 22.8) out of a maximum score of 50. Items that tended not to be reported include authors contact details, participant (settings), randomization procedures and trial registration. Posters achieved lower scores compared to oral abstracts (-2.96; 95% CI -4.86, -1.07; P < 0.01). Additionally, an abstract word count greater than 251 words was associated with higher total score (3.28; 95% CI 0.74, 5.82; P = 0.012). A weak association (0.29, 95% CI: -0.03-0.62, p = 0.07) between year of abstract publication and an improvement in overall reporting score over time was evident.

Limitations: Only one society congress were assessed which may impact the generalisability of the results.

Conclusions: In relation to the CONSORT reporting Randomized Controlled Trials in Journal and Conference Abstracts checklist, RCT abstracts presented at EOS congress between 2015-2024 remain sub-optimal with reporting of key items lacking. However, reporting quality scores have shown an association with type of presentation (oral or poster), abstract word count and some evidence of improvement over time. Measures to encourage clear and consistent RCT abstract reporting are required.