Unpublished clinical trials of common rheumatic diseases

Fragility of randomised controlled trials for systemic lupus erythematosus and lupus nephritis therapies

OBJECTIVE

We aimed to evaluate the robustness of phase III randomised controlled trials (RCTs) for SLE and lupus nephritis (LN) using the fragility index (FI), the reverse FI (RFI) and the fragility quotient (FQ).

METHODS

We searched for phase III RCTs that included patients with active SLE or LN. Data on primary endpoints, total participants and the number of events for each arm were obtained. We calculated the FI score for RCTs with statistically significant results (number of patients required to change from event to non-event to make the study lose statistical significance), the RFI for RCTs without statistically significant results (number of patients required to change from non-event to event to make study gain statistical significance) and the FQ score for both (FI or RFI score divided by the sample size).

RESULTS

We evaluated 20 RCTs (16 SLE, four LN). The mean FI/RFI score was 13.6 (SD 6.6). There were nine RCTs with statistically significant results (seven SLE, two LN), and the mean FI score was 10.2 (SD 6.2). The lowest FI was for the ILLUMINATE-2 trial (FI=2), and the highest FI was for the BLISS-52 trial (FI=17).Twelve studies had non-statistically significant results (10 SLE, two LN) with a mean RFI score of 15.6 (SD 6.1). The lowest RFI was for the ILLUMINATE-1 trial (RFI=4), and the highest RFI was for the TULIP-1 trial (RFI=27). The lowest FQ scores were found in the ILLUMINATE trials and the highest in the Rituximab trials (EXPLORER and LUNAR), meaning that the last ones were the most robust results after accounting for sample size.

CONCLUSIONS

The evidence of therapies for patients with SLE and LN is derived mostly from fragile RCTs. Clinicians and trialists must be aware of the fragility of these RCTs for clinical decision-making and designing trials for novel therapeutics.

Dissemination of Registered COVID-19 Clinical Trials (DIRECCT): a cross-sectional study

BACKGROUND

The results of clinical trials should be completely and rapidly reported during public health emergencies such as COVID-19. This study aimed to examine when, and where, the results of COVID-19 clinical trials were disseminated throughout the first 18 months of the pandemic.

METHODS

Clinical trials for COVID-19 treatment or prevention were identified from the WHO ICTRP database. All interventional trials with a registered completion date ≤ 30 June 2021 were included. Trial results, published as preprints, journal articles, or registry results, were located using automated and manual techniques across PubMed, Google Scholar, Google, EuropePMC, CORD-19, the Cochrane COVID-19 Study Register, and clinical trial registries. Our main analysis reports the rate of dissemination overall and per route, and the time from registered completion to results using Kaplan-Meier methods, with additional subgroup and sensitivity analyses reported.

RESULTS

Overall, 1643 trials with completion dates ranging from 46 to 561 days prior to the start of results searches were included. The cumulative probability of reporting was 12.5% at 3 months from completion, 21.6% at 6 months, and 32.8% at 12 months. Trial results were most commonly disseminated in journals (n = 278 trials, 69.2%); preprints were available for 194 trials (48.3%), 86 (44.3%) of which converted to a full journal article. Trials completed earlier in the pandemic were reported more rapidly than those later in the pandemic, and those involving ivermectin were more rapidly reported than other common interventions. Results were robust to various sensitivity analyses except when considering only trials in a "completed" status on the registry, which substantially increased reporting rates. Poor trial registry data on completion status and dates limits the precision of estimates.

CONCLUSIONS

COVID-19 trials saw marginal increases in reporting rates compared to standard practice; most registered trials failed to meet even the 12-month non-pandemic standard. Preprints were common, complementing journal publication; however, registries were underutilized for rapid reporting. Maintaining registry data enables accurate representation of clinical research; failing to do so undermines these registries' use for public accountability and analysis. Addressing rapid reporting and registry data quality must be emphasized at global, national, and institutional levels.

Time to Publication and Time-Lag Publication Bias for Randomized Trials on Connective Tissue Diseases

OBJECTIVE

To assess the time from completion to publication of randomized controlled trials (RCTs) on connective tissue diseases (CTDs), investigate the factors associated with, and explore the influence of significance of study results on time to publication (time-lag publication bias).

METHODS

We included interventional, phase 2/3, 3, or 4 RCTs on CTDs registered in Clinicaltrials.gov from 2000 to 2016, whose results had been published in a peer-review journal less than 5 years after their completion. Main trial features, including the significance of primary outcome results, were collected. Time to publication was the time from study completion to the earliest publication date. Multivariable linear regression was used to identify factors associated with time to publication.

RESULTS

We included 62 studies, mostly phase 3 (61%) trials on pharmacologic treatments (94%); we recruited patients with systemic lupus (55%) or systemic sclerosis (23%) and planned to enroll a median of 131 (IQR [interquartile range]: 61-288) patients. Twenty-two (35%) reported at least a statistically significant primary outcome. Median time to publication was 28 months (IQR: 17-36). In a multivariable analysis, time to publication progressively improved over time (faster publication in recent years, with the average time to publication decreasing by 1.3 [95% CI: 0.3-2.3] months per year) and was not influenced by the significance of primary outcome results, funder, impact factor of the journal, number of recruiting countries, and comparator.

CONCLUSION

A high proportion of CTDs-RCTs is published beyond 2 years from completion. We did not find evidence of time-lag publication bias, and time to publication improved over time.