Complete and transparent reporting of primary end points of randomized trials in the dermatology literature: A comparison of registered and published primary end points

Systematic review of sample size calculations and reporting in randomized controlled trials in ophthalmology over a 20-year period

PURPOSE

Randomized Controlled Trials (RCTs) are considered the gold standard for the practice of evidence-based medicine. The purpose of this study is to systematically assess the reporting of sample size calculations in ophthalmology RCTs in 5 leading journals over a 20-year period. Reviewing sample size calculations in ophthalmology RCTs will shed light on the methodological quality of RCTs and, by extension, on the validity of published results.

METHODS

The MEDLINE database was searched to identify full reports of RCTs in the journals Ophthalmology, JAMA Ophthalmology, American Journal of Ophthalmology, Investigative Ophthalmology and Visual Science, and British Journal of Ophthalmology between January and December of the years 2000, 2010 and 2020. Screening identified 559 articles out of which 289 met the inclusion criteria for this systematic review. Data regarding sample size calculation reporting and trial characteristics was extracted for each trial by independent investigators.

RESULTS

In 2020, 77.9% of the RCTs reported sample size calculations as compared with 37% in 2000 (p < 0.001) and 60.7% in 2010 (p = 0.012). Studies reporting all necessary parameters for sample size recalculation increased significantly from 17.2% in 2000 to 39.3% in 2010 and 43.0% in 2020 (p < 0.001). Reporting of funding was greater in 2020 (98.8%) compared with 2010 (89.3%) and 2000 (53.1%). Registration in a clinical trials database occurred more frequently in 2020 (94.2%) compared to 2000 (1.2%; p < 0.001) and 2010 (68%; p < 0.001). In 2020, 38.4% of studies reported different sample sizes in the online registry from the published article. Overall, the most studied area in 2000 was glaucoma (29.6% of RCTs), whereas in 2010 and 2020, it was retina (40.2 and 37.2% of the RCTs, respectively). The number of patients enrolled in a study and the number of eyes studied was significantly greater in 2020 compared to 2000 and 2010 (p < 0.001).

CONCLUSION

Sample size calculation reporting in ophthalmology RCTs has improved significantly between the years 2000 and 2020 and is comparable to other fields in medicine. However, reporting of certain parameters remains inconsistent with current publication guidelines.

Completeness and consistency of primary outcome reporting in COVID-19 publications in the early pandemic phase: a descriptive study

BACKGROUND

The COVID-19 pandemic saw a steep increase in the number of rapidly published scientific studies, especially early in the pandemic. Some have suggested COVID-19 trial reporting is of lower quality than typical reports, but there is limited evidence for this in terms of primary outcome reporting. The objective of this study was to assess the prevalence of completely defined primary outcomes reported in registry entries, preprints, and journal articles, and to assess consistent primary outcome reporting between these sources.

METHODS

This is a descriptive study of a cohort of registered interventional clinical trials for the treatment and prevention of COVID-19, drawn from the DIssemination of REgistered COVID-19 Clinical Trials (DIRECCT) study dataset. The main outcomes are: 1) Prevalence of complete primary outcome reporting; 2) Prevalence of consistent primary outcome reporting between registry entry and preprint as well as registry entry and journal article pairs.

RESULTS

We analyzed 87 trials with 116 corresponding publications (87 registry entries, 53 preprints and 63 journal articles). All primary outcomes were completely defined in 47/87 (54%) registry entries, 31/53 (58%) preprints and 44/63 (70%) journal articles. All primary outcomes were consistently reported in 13/53 (25%) registry-preprint pairs and 27/63 (43%) registry-journal article pairs. No primary outcome was specified in 13/53 (25%) preprints and 8/63 (13%) journal articles. In this sample, complete primary outcome reporting occurred more frequently in trials with vs. without involvement of pharmaceutical companies (76% vs. 45%), and in RCTs vs. other study designs (68% vs. 49%). The same pattern was observed for consistent primary outcome reporting (with vs. without pharma: 56% vs. 12%, RCT vs. other: 43% vs. 22%).

CONCLUSIONS

In COVID-19 trials in the early phase of the pandemic, all primary outcomes were completely defined in 54%, 58%, and 70% of registry entries, preprints and journal articles, respectively. Only 25% of preprints and 43% of journal articles reported primary outcomes consistent with registry entries.