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Factors Affecting Outcomes of Craniofacial Clinical Trials

PURPOSE

This study aims to provide a cross-sectional view of craniofacial trials and to identify factors associated with completion, publication, and trial longevity.

MATERIALS AND METHODS

This is a cross-sectional study of cleft and craniofacial clinical trials registered with ClinicalTrials.gov between September 1999 and April 2020. Predictor variables included funding source, trial design, trial location, number of recruitment sites, and investigator specialty.Study outcomes were completion status, publication status, and trial duration. Univariate comparisons and multivariate regression models were calculated for each outcome.

RESULTS

The final sample included 179 clinical trials pertaining to craniofacial care. Nearly all trials were single-center (86.5%), and roughly half of trials were interventional (57.0%) or conducted in the United States (40.5%). No single specialty predominated, although plastic surgery (13.4%) was the most common investigator specialty. The completion rate was 82.7%, the publication rate was 40.8%, and the mean trial duration was 39.1 months. Interventional design (odds ratio = 0.30, P = 0.02) and United States location (odds ratio = 0.15, P < 0.01) were each independently associated with lower odds of trial completion. Trial longevity was independently associated with the National Institute of Health-funding (P < 0.01) and multicenter design (P < 0.01).

CONCLUSIONS

Craniofacial trials are multidisciplinary and have a high rate of completion. Although most existing trials were conducted at only a single-center, multicenter efforts significantly increased trial longevity without compromising completion and publication rates. Given the diverse array of conditions and lines of inquiry that compose craniofacial care, it is reassuring that collaboration did not negatively affect trial outcomes.

Which Factors Affect the Completion and Publication of Dental Implant Trials?

PURPOSE

Clinical decision making in implant dentistry may be vulnerable to industry influence. The purpose of this study was to identify factors associated with the completion and publication of implant trials.

MATERIALS AND METHODS

This was a cross-sectional study of dental implant trials registered with ClinicalTrials.gov. The predictor variables were composed of a set of study characteristics including study design (investigational or observational), topic, sample size (≤50 or >50 participants), investigator specialty (periodontics, oral-maxillofacial surgery, prosthodontics, general/implantology, or other), study site (United States or international), and industry funding (yes or no). The outcome variables were time to study completion and time to publication. Reverse Kaplan-Meier analyses were used to determine time-to-event probabilities, and Cox proportional hazards models were used to identify factors associated with study completion and publication.

RESULTS

A total of 317 trials were included in the final sample. The median trial duration was 2.3 years, and the median time from completion to publication was 1.9 years. Compared with periodontist-led trials, oral and maxillofacial surgeon-led trials had greater success with publication (publication rate, 73.0% vs 54.4%; P = .01) but were less likely to be conducted in the United States (US site present, 8.8% vs 46.0%; P < .01). Trials that received industry funding were able to extend their operations by an average period of 1.2 years (P < .01). The projected trial completion rate at 5 years was 78.0%, and the projected publication rate 5 years after completion was 94.0%. Multivariate Cox regression showed that both industry-funded trials (hazard ratio, 0.66; P < .01) and pharmacologic studies (hazard ratio, 1.69; P = .02) were significantly associated with the completion rate. Among completed trials, neither industry sponsorship nor any other factor influenced the publication rate over time.

CONCLUSIONS

Trials that were industry funded had lower rates of completion but not publication. Future efforts should explore the reasons for research waste and improve US oral and maxillofacial surgeon involvement in clinical trial research.