Characteristics of pediatric cardiovascular clinical trials registered on ClinicalTrials.gov

Abstract

Background: ClinicalTrials.gov is an National Institutes of Health-sponsored registry of federally and privately funded trials. We sought to determine fundamental characteristics of registered pediatric cardiovascular trials (PCVTs).

Methods: A data set including 68,134 interventional clinical trials was downloaded from ClinicalTrials.gov and entered into a relational database. Aggregate data from PCVTs were compared with other trial specialties. Multivariable logistic regression was used to evaluate factors associated with improved trial quality metrics including blinding and randomization.

Results: Between July 1, 2005, and September 27, 2010, 5035 (7%) registered trials targeted pediatric populations, including 213 PCVTs (4.2%), 1,176 pediatric infectious disease trials (23%), 664 pediatric mental health trials (13%), and 346 pediatric hematology/oncology trials (7%). Median (interquartile range) PCVT enrollment was 65 subjects (36-186) and median study duration was 2.3 years (1.3-3.7). The most common PCVTs targeted acquired diseases including hypertension (n = 41, 14%), obesity (n = 26, 9%), pulmonary hypertension (n = 25, 9%), and dyslipidemia (n = 19, 7%). Important factors associated with improved quality metrics included National Institutes of Health as opposed to industry funding (OR, 1.9; P < .0001); trial location (trials with both US and foreign enrollment vs trials with US only or foreign only enrollment, P = .02) and trials restricted to younger children as opposed to trials including adolescents (OR, 1.4; P < .0001).

Conclusion: PCVTs represent a small proportion of clinical trials relative to other pediatric subspecialties. Most PCVTs tend to parallel adult morbidities while there is a relative paucity of trials focused on congenital heart disease. These data may be useful to stakeholders in informing decisions regarding the conduct of PCVTs, and to provide insight into mechanisms to advance PCVT infrastructure.

Figure I

Consortium diagram: Inclusion criteria and methods for study selection. *Clinical Trials refers to those trials registered as “interventional studies” on ClinicalTrials.gov. Interventional studies are defined by ClinicalTrials.gov as those in which an investigator assigns an intervention (including diagnostic, therapeutic or other types of interventions) based on a protocol. † Non-interventional or observational studies were excluded because there are no current registration requirements at ClinicalTrials.gov. ‡Methods for identification of adult cardiovascular trials described previously. These trials exclude trials enrolling participants < 18 years. § Trials classified into pediatric subspecialties based on manual review of the trial characteristics as previously reported. ||A pediatric cardiologist reviewed all adult cardiovascular trials that also enrolled subjects < 18 years of age and identified those that focused on pediatric cardiovascular diseases or conditions.

Figure II

Pediatric Cardiovascular Trial intervention categories and funding source. PDA = Patent Ductus Arteriosus; CPR = Cardiopulmonary Resuscitation; CHD = Congenital Heart Disease.

Figure III

Industry and NIH funded pediatric cardiovascular trials compared to other pediatric sub-specialties and adult cardiovascular trials. Funding source is derived from the submitted lead sponsor and collaborator information. Pediatric cardiovascular trials restricted to those excluding participants > 18 years while adult cardiovascular trials restricted to those excluding participants < 18 years.

Figure IV

Multivariable logistic regression for use of randomization and blinding in pediatric trials. Era 1: July05–Sep07 (before the FDA Amendments Act registry requirements were implemented), and era 2: Oct07–Sep10 (after implementation)