Rationale
ClinicalTrials.gov is the largest trial registry in the world. Strengthened registration requirements, including federal mandates in 2007, have increased study representation. A systematic evaluation of all registered studies has been limited by the absence of an aggregate dataset and specialty-specific search terms.
Objective
We leveraged a newly transformed database containing annotated data from ClinicalTrials.gov to define the portfolio of interventional clinical research in pulmonary, critical care, and sleep medicine.
Methods
Analysis was restricted to studies registered after September 2007 through September 2010 and defined as “interventional” (n=40,970). A specialty-specific study dataset (n= 2,226) was created using disease condition terms provided by data submitters and medical subject heading terms generated by a National Library of Medicine algorithm. Trial characteristics were extracted and summarized using descriptive statistics.
Measurements and Main Results
Pulmonary, critical care, and sleep medicine trials composed 5.4% of all interventional studies registered over the 3-year period. In contrast, oncology and cardiovascular disease comprised 21.9% and 8.4% of trials respectively. Within pulmonary trials, asthma and chronic obstructive pulmonary disease were the most studied conditions (27.4% and 21.8% of studies), and measures of lung function or safety were the most frequent primary outcomes. Nearly two-thirds of trials indicated enrollment of 100 patients or fewer, and a majority of studies were phase II or III trials. The single largest funding source (43.5%) was industry and study characteristics varied by funding source.
Conclusions
We applied a novel approach to describe the portfolio of interventional clinical research in pulmonary medicine. Our results indicate a disparity between trial representation and the burden of respiratory disease. Resources should be targeted across the spectrum of pulmonary research to address this discrepancy.
Background
Transfer delays for primary percutaneous coronary intervention (PPCI) may increase mortality in patients with ST-segment elevation myocardial infarction (STEMI). We examined the association between door 1 to door 2 (D1D2) time, a measure capturing the entire transfer process, and outcomes in patients undergoing inter-hospital transfer for primary PCI.
Methods and Results
We evaluated the relationship between D1D2 time and the 90 day incidence of death, shock, and heart failure in the sub-set of 2075 (36.1%) of 5745 patients who underwent inter-hospital transfer for PPCI in the APEX-AMI trial. There was no significant difference in the 90 day incidence of death, shock, and heart failure between the transferred and the non-transferred groups (10.3% vs 10.2%, p=0.89). The median difference in symptom to balloon time between the two groups was 45 minutes (229 vs 184, p<0.001). The primary outcome per 30 minute delay was higher for patients with a D1D2 time ≤ 150 minutes (HR 1.19: 95% Confidence Interval [CI], 1.06 to 1.33 p=0.004) but not for D1D2 times > 150 minutes (HR, 0.99: 95% CI, 0.96 to 1.02; p=0.496). The association between longer D1D2 time and worsening outcome was no longer statistically significant after multivariable adjustment.
Conclusion
Longer transfer times were associated with higher rate of death, shock, and heart failure among patients undergoing inter-hospital transfer from PPCI, although this difference did not persist after adjusting for baseline characteristics.
Clinical Trial Registration Information
URL: www.clincaltrials.gov, Unique Identifier: NCT00091637
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