Reporting quality in clinical research is critical for evidence-based medicine and reproducibility of clinical studies. Previous work has mostly focused on the reporting quality of clinical trials and observational longitudinal studies. However, few studies have examined the reporting quality of trend analyses. Moreover, the reporting of recommended statistical metrics in trend analyses remains largely unclear. Therefore, we assessed the reporting quality of trend analyses based on reporting of recommended statistical metrics. We systematically searched the PubMed for the trend-analysis articles published in 10 leading medicine and oncology journals over an 11-year period (2008–2018). Studies published after 2019 were excluded due to a sudden, significant increase in publication numbers during and immediately after the COVID-19 pandemic. Only original articles, research letters, and meta-analyses/systematic reviews were included. We scored the reporting quality of these articles based on whether they reported p-values, effect sizes, beta/coefficient/slope/annual-percentage-change (APC). 297 articles met the inclusion criteria. Among these, 193 (66.0%) reported p-values and 216 (72.7%) reported effect sizes. Only 13 (5.8%) analyses reported neither p-values/effect sizes nor beta/coefficient/slope/APC. In multivariable regression models, authors affiliated with epidemiology departments were less likely to report effect sizes, whereas those from statistics departments were more likely to do so. Interestingly, U.S.-based senior authors (versus non-U.S.) more likely reported p-values. No factors were independently associated with reporting APC. Overall, the reporting quality of trend analyses in leading medicine and oncology journals appears moderate and warrants improvement. We thus call for increased awareness and further research on reporting quality in trend analyses in oncology research and beyond.
