Current understanding of chronic diseases is based on crude clinical characterization, imaging studies, and laboratory testing that has evolved over decades. The Measurement to Understand Reclassification of Disease of Cabarrus/Kannapolis (MURDOCK) Study is a multi-tiered, longitudinal study designed to enable classification of chronic diseases using clinically annotated biospecimen collections, -omic technologies, electronic health records, and standard epidemiological methods. We expect that detailed molecular classification will improve mechanistic understanding of chronic diseases, augmenting discovery and testing of new treatments, and allowing refined selection of prevention and treatment strategies. The MURDOCK Study Community Registry and Biorepository will serve as a bridge for validation of initial exploratory studies, a platform for future prospective studies in targeted populations, and a resource of both data (analytical and clinical) and samples for cross-registry meta-analyses and comparative population studies. Participation of local health care providers and the Cabarrus County/Kannapolis, NC, community will facilitate future medical research and provide the opportunity to educate and inform the public about genomic research, actively engaging them in shaping the future of medical discovery and treatment of chronic diseases. We present the rationale and study design for the MURDOCK Community Registry and Biorepository and baseline characteristics of the first 6000 participants.
Disease reclassification; community registry; biorepository
Facing critically low return per dollar invested on clinical research and clinical care, the American biomedical enterprise is in need of a significant transformation. A confluence of high-throughput “omic” technologies and increasing adoption of the electronic health record has fueled excitement for a new paradigm for biomedical research and practice. The ability to simultaneously measure thousands of molecular variables and assess their relationships with clinical data collected during the course of care could enable reclassification of disease not only by gross phenotypic observation but according to underlying molecular mechanism and influence of social determinants.In turn, this reclassification could enable development of targeted therapeutic interventions as well as disease prevention strategies at the individual and population levels.
The MURDOCK Study consists of distinct project “horizons” or stages. Horizon 1 entailed the generation and analysis of molecular data for existing large,clinically well-annotated cohorts in four disease areas. Horizon 1.5 involves creating and maintaining a 50,000-person,community volunteer registry for biomarker signature validation and prospective studies, including integration of environmental and social data. Horizon 2 leverages and prospectively recruits Horizon 1.5 volunteers, and extends the study to additional disease areas of interest. Horizon 3 will expand the study through regional, national,and international partnerships.
The MURDOCK Study embodies a new model of team science investigation and represents a significant resource for translational research. The study team invites inquiries to form new collaborations to exploit the rich resources provided by these biospecimens and associated study data.
Stratified medicine; personalized medicine; biomarkers; disease reclassification; community registry; biorepository
Congress has authorized the U.S. Food and Drug Administration (FDA) to provide industry sponsors with a 6-month extension of drug marketing rights under the Pediatric Exclusivity Provision if FDA-requested pediatric drug trials are conducted. The cost and economic return of pediatric exclusivity to industry sponsors has been shown to be highly variable. We sought to determine the cost of performing pediatric exclusivity trials within a single therapeutic area and the subsequent economic return to industry sponsors.
We evaluated 9 orally administered anti-hypertensive drugs submitted to the FDA under the Pediatric Exclusivity Provision from 1997–2004 and obtained key elements of the clinical trial designs and operations. Estimates of the costs of performing the studies were generated and converted into after-tax cash outflow. Market sales were obtained and converted into after-tax inflows based on 6 months of additional patent protection. Net economic return and net return-to-cost ratios were determined for each drug.
Of the 9 anti-hypertensive agents studied, an average of 2 studies per drug was performed, including at least 1 pharmacokinetic study and a safety and efficacy study. The median cost of completing a pharmacokinetic trial was $862,000 (range: $556,000–1.8 million). The median cost of performing safety and efficacy trials for these agents was $4.3 million (range: $2.1 million–12.9 million). The ratio of net economic return to cost was 17 (range: 4–64.7).
We found that, within a cohort of anti-hypertensive drugs, the Pediatric Exclusivity Provision has generated highly variable, yet lucrative returns to industry sponsors.
clinical trials; hypertension; pediatrics; drugs; cost-benefit analysis
The ClinicalTrials.gov trial registry was expanded in 2008 to include a database for reporting summary results. We summarize the structure and contents of the results database, provide an update of relevant policies, and show how the data can be used to gain insight into the state of clinical research.
We analyzed ClinicalTrials.gov data that were publicly available between September 2009 and September 2010.
As of September 27, 2010, ClinicalTrials.gov received approximately 330 new and 2000 revised registrations each week, along with 30 new and 80 revised results submissions. We characterized the 79,413 registry and 2178 results of trial records available as of September 2010. From a sample cohort of results records, 78 of 150 (52%) had associated publications within 2 years after posting. Of results records available publicly, 20% reported more than two primary outcome measures and 5% reported more than five. Of a sample of 100 registry record outcome measures, 61% lacked specificity in describing the metric used in the planned analysis. In a sample of 700 results records, the mean number of different analysis populations per study group was 2.5 (median, 1; range, 1 to 25). Of these trials, 24% reported results for 90% or less of their participants.
ClinicalTrials.gov provides access to study results not otherwise available to the public. Although the database allows examination of various aspects of ongoing and completed clinical trials, its ultimate usefulness depends on the research community to submit accurate, informative data.
elderly; clopidogrel; glycoprotein IIb/IIIa blockers
Few data exist to guide antiarrhythmic drug therapy for sustained ventricular tachycardia (VT)/ventricular fibrillation (VF) after acute myocardial infarction (MI). The objective of this analysis was to describe survival of patients with sustained VT/VF post-MI according to antiarrhythmic drug treatment.
Design & Setting
We conducted a retrospective analysis of ST-segment elevation MI patients with sustained VT/VF in GUSTO IIB and III and compared all-cause death in patients receiving amiodarone, lidocaine, or no antiarrhythmic. We used Cox proportional hazards modeling and inverse weighted estimators to adjust for baseline characteristics, beta-blocker use, and propensity to receive antiarrhythmics. Due to non-proportional hazards for death in early follow-up (0–3 hours after sustained VT/VF) compared with later follow-up (>3 hours), we analyzed all-cause mortality using time-specific hazards.
Patients & Interventions
Among 19,190 acute MI patients, 1126 (5.9%) developed sustained VT/VF and met the inclusion criteria. Patients received lidocaine (n=664, 59.0%), amiodarone (n=50, 4.4%), both (n=110, 9.8%), or no antiarrhythmic (n=302, 26.8%).
In the first 3 hours after VT/VF, amiodarone (adjusted HR 0.39, 95% CI 0.21–0.71) and lidocaine (adjusted HR 0.72, 95% CI 0.53–0.96) were associated with a lower hazard of death—likely evidence of survivor bias. Among patients who survived 3 hours, amiodarone was associated with increased mortality at 30 days (adjusted HR 1.71, 95% CI 1.02–2.86) and 6 months (adjusted HR 1.96, 95% CI 1.21–3.16) but lidocaine was not at 30 days (adjusted HR 1.19, 95% CI 0.77–1.82) and 6 months (adjusted HR 1.10, 95% CI 0.73–1.66).
Among patients with acute MI complicated by sustained VT/VF who survive 3 hours, amiodarone, but not lidocaine, is associated with an increased risk of death; reinforcing the need for randomized trials in this population.
ventricular arrhythmia; antiarrhythmic drug therapy; clinical trials; acute coronary syndrome; ventricular tachycardia; ventricular fibrillation
We examined the relation of maximal in-hospital diuretic dose to weight loss, changes in renal function, and mortality in hospitalised heart failure (HF) patients.
In ESCAPE, 395 patients received diuretics in-hospital. Weight was measured at baseline, discharge, and every other day before discharge. Weight loss was defined as the difference between baseline and last in-hospital weight. Mortality was assessed using a log-logistic model with non-zero background.
Median weight loss: 2.8 kg (0.7, 6.1); mean: 3.7 kg (22% of values <0). Weight loss and maximum in-hospital dose were correlated (p = 0.0007). Baseline weight, length of stay, and baseline brain natriuretic peptide were significant predictors of weight loss. After adjusting for these, dose was not a significant predictor of weight loss. A strong relation between dose and mortality was seen (p = 0.003), especially at >300 mg/day. Dose remained a significant predictor of mortality after adjusting for baseline variables that significantly predicted mortality. Correlation between maximal dose and creatinine level change was not significant (r = 0.043; p = 0.412)
High diuretic doses during HF hospitalisation are associated with increased mortality and poor 6-month outcome.
diuretics; heart failure; outcomes
Advances in human health require the efficient and rapid translation of scientific discoveries into effective clinical treatments; this process in turn depends upon observational data gathered from patients, communities, and public-health research that can be used to guide basic scientific investigation. Such bidirectional translational science, however, faces unprecedented challenges due to the rapid pace of scientific and technological development, as well as the difficulties of negotiating increasingly complex regulatory and commercial environments that overlap the research domain. Further, numerous barriers to translational science have emerged among the nation’s academic research centers, including basic structural and cultural impediments to innovation and collaboration, shortages of trained investigators, and inadequate funding.
To address these serious and systemic problems, in 2006, the National Institutes of Health created the Clinical and Translational Science Awards (CTSA) program, which aims to catalyze the transformation of biomedical research at a national level, speeding the discovery and development of therapies, fostering collaboration, engaging communities, and training succeeding generations of clinical and translational researchers. The authors report in detail on the planning process, begun in 2008, that was used to engage stakeholders and to identify, refine, and ultimately implement the CTSA program’s overarching strategic goals. They also discuss the implications and likely impact of this strategic planning process as it is applied among the nation’s academic health centers.
To quantify the frequency and type of new safety information arising from studies performed under the auspices of the Pediatric Exclusivity Program, to describe the dissemination of these findings in the peer-reviewed literature and compare this with the FDA review, and to describe their effect on pediatric labeling.
Cohort study of the 365 trials performed for 153 drugs.
The Pediatric Exclusivity incentive from December 1997 through September 2007.
Food and Drug Administration publicly available records and peer-reviewed literature retrievable by Medline search.
New safety findings obtained from the trials completed for exclusivity.
Main Outcome Measures
Concordance of the information highlighted in the peer-reviewed article abstracts with the information in the FDA labeling and drug reviews.
There were 137 labeling changes; we evaluated 129 of these (the 8 selective serotonin reuptake inhibitors were excluded from review). Thirty-three products (26%) had pediatric safety information added to the labeling. Of these, 12 products had neuropsychiatric safety findings, and 21 had other important safety findings. Only 16/33 (48%) of these trials were reported in the peer-reviewed literature; however, 7/16 of these publications focused on findings substantively different from those highlighted in the FDA reviews and labeling changes.
Medication adverse events in children often differ from those in adults, particularly those that are neuropsychiatric in nature. Labeling changes for pediatric use demonstrate that pediatric drug studies provide valuable and unique safety data that can guide the use of these drugs in children. Unfortunately, most these articles are not published, and almost half of the published articles focus their attention away from the crucial safety data.
There is conflicting information about whether sex-differences modulate short-term mortality following acute coronary syndromes (ACS).
To investigate the relationship between sex and 30-day mortality in ACS, and determine whether this relationship is modified by clinical syndrome or coronary anatomy using a large database across the spectrum of ACS and adjusting for potentially confounding clinical covariates.
Design Setting and Participants
Data from 11 ACS trials from 1993 to 2006 were pooled. Of 136,247 patients, 38,048 (28%) were women; 102,004 (26% women) STEMI, 14,466 (29% women) NSTEMI and 19,777 (40% women) unstable angina (UA).
Main Outcome Measure
Thirty-day mortality following ACS.
Mortality at 30 days was 9.6% in women and 5.3% in men (odds ratio [OR] 1.91, 95% confidence interval [CI] 1.83–2.00). After multivariable adjustment, mortality was not significantly different between women and men (adjusted OR 1.06, 95% CI 0.99–1.15). Importantly, a significant sex by type of ACS interaction was demonstrated (P<0.001). In STEMI, 30-day mortality was higher among women (adjusted OR 1.15, 95% CI 1.06–1.24), whereas NSTEMI (adjusted OR 0.77, 95% CI 0.63–0.95), and UA mortality was lower among women (adjusted OR 0.55, 95% CI 0.43–0.70). In a cohort of 35,128 patients with angiographic data, women more often had non-obstructive (15% vs. 8%,) and less often had 2-vessel (25% vs. 28%) and 3-vessel (23% vs. 26%) coronary disease regardless of ACS type. After additional adjustment for angiographic disease severity, 30-day mortality among women was not significantly different than men, regardless of ACS type. The relationship between sex and 30-day mortality was similar across the levels of angiographic disease severity (p-value for interaction =0.70),
Sex-based differences exist in 30-day mortality among ACS patients and vary depending on clinical presentation. However, these differences are markedly attenuated following adjustment for clinical differences and angiographic data.
Risk factors for cardiovascular events are well established in general populations and those with diabetes but have been sparsely studied in impaired glucose tolerance (IGT). We sought to identify predictors of (1) a composite cardiovascular outcome (cardiovascular death, non-fatal myocardial infarction and non-fatal stroke) and (2) cardiovascular death, among patients with IGT.
We studied participants enrolled in the Nateglinide and Valsartan in Impaired Glucose Tolerance Outcomes Research (NAVIGATOR) trial. Predictors of cardiovascular events were identified in observational analyses.
Clinical trial participants in 40 countries.
9306 participants with biochemically confirmed IGT at high risk of cardiovascular events participated in NAVIGATOR.
Primary and secondary outcome measures
Cox proportional hazard regression models were constructed using variables (demographic data, medical history, clinical features, biochemical results and ECG findings) recorded at baseline to identify variables associated with and predictive of cardiovascular events.
Over 6.4 years, 639 (6.9%) participants experienced a cardiovascular event, and 244 (2.6%) cardiovascular death. While predictors of both outcomes included established risk factors such as existing cardiovascular disease, male gender, older age, current smoking status and higher low-density lipoprotein cholesterol, other variables such as reduced estimated glomerular filtration rate, previous thromboembolic disease, atrial fibrillation, higher urinary albumin/creatinine ratio and chronic obstructive pulmonary disease were also important predictors. Glycaemic measures were not predictive of cardiovascular events. c-Statistics for predicting cardiovascular events and cardiovascular death were 0.74 and 0.82, respectively. This compares with c-statistics for cardiovascular events and cardiovascular death of 0.65 and 0.71, respectively, using the classical Framingham risk factors of age, total cholesterol, high-density lipoprotein cholesterol, systolic blood pressure, treatment for hypertension and smoking status.
The most powerful independent predictors of cardiovascular events in IGT included both established risk factors and other variables excluding measures of glycaemia, allowing effective identification of high-risk individuals.
Trials of anemia correction in chronic kidney disease have found either no benefit or detrimental outcomes of higher targets. We did a secondary analysis of patients with chronic kidney disease enrolled in the Correction of Hemoglobin in the Outcomes in Renal Insufficiency trial to measure the potential for competing benefit and harm from achieved hemoglobin and epoetin dose trials. In the 4 month analysis, significantly more patients in the high-hemoglobin compared to the low-hemoglobin arm were unable to achieve target hemoglobin and required high-dose epoetin-α. In unadjusted analyses, the inability to achieve a target hemoglobin and high-dose epoetin-α were each significantly associated with increased risk of a primary endpoint (death, myocardial infarction, congestive heart failure or stroke). In adjusted models, high-dose epoetin-α was associated with a significant increased hazard of a primary endpoint but the risk associated with randomization to the high hemoglobin arm did not suggest a possible mediating effect of higher target via dose. Similar results were seen in the 9 month analysis. Our study demonstrates that patients achieving their target had better outcomes than those who did not; and among subjects who achieved their randomized target, no increased risk associated with the higher hemoglobin goal was detected. Prospective studies are needed to confirm this relationship and determine safe dosing algorithms for patients unable to achieve target hemoglobin.
anemia; chronic kidney disease; epoetin-α; dose; epidemiology and outcomes
The CHOIR trial in anemic patients with chronic kidney disease compared epoetin-alfa treatment with low (11.3 g/l) and high (13.5 g/l) hemoglobin targets on the composite end point of death, hospitalization for heart failure, stroke, and myocardial infarction. However, other anemia management trials in patients with chronic kidney disease found there was increased risk when hemoglobin is targeted above 13 g/dl. In this secondary analysis of the CHOIR trial, we compared outcomes among the subgroups of patients with diabetes and heart failure to describe the comparative relationship of treatment to these two different hemoglobin goals. By Cox regression analysis, there was no increased risk associated with the higher hemoglobin target among patients with heart failure. In patients without heart failure, however, the hazard ratio (1.86) associated with the higher target was significant. Comparing survival curves in an unadjusted model, patients with diabetes did not have a greater hazard associated with the higher target. Subjects without diabetes had a significantly greater hazard in the high as compared to the low target, but the interaction between diabetes and the target was not significant. We suggest that the increased risks associated with higher hemoglobin targets are not clinically apparent among subgroups with greater mortality risk. These differential outcomes underscore the need for dedicated trials in these subpopulations.
anemia; diabetes mellitus; heart failure; kidney
On the basis of our experience in drug and device development, we have identified six broad categories of issues that profoundly affect the probability for successful translation of basic scientific discoveries into effective therapies. Within each category, we propose a series of questions that form the beginnings of a self-guided global risk assessment tool. Although this preliminary tool will require validation and adjustment, we offer it to stimulate a discussion about more rigorous methods for selecting and conducting translational projects.
To investigate whether the beneficial and harmful effects of platelet glycoprotein IIb/IIIa receptor blockers in non‐ST elevation acute coronary syndromes (NSTE‐ACS) depend on age.
A meta‐analysis of six trials of platelet glycoprotein IIb/IIIa receptor blockers in patients with NSTE‐ACS (PRISM, PRISM‐PLUS, PARAGON‐A, PURSUIT, PARAGON‐B, GUSTO IV‐ACS; n = 31 402) was performed. We applied multivariable logistic regression analyses to evaluate the drug effects on death or non‐fatal myocardial infarction at 30 days, and on major bleeding, by age subgroups (<60, 60–69, 70–79, ⩾80 years). We quantified the reduction of death or myocardial infarction as the number needed to treat (NNT), and the increase of major bleeding as the number needed to harm (NNH).
Subgroups had 11 155 (35%), 9727 (31%), 8468 (27%) and 2049 (7%) patients, respectively. The relative benefit of platelet glycoprotein IIb/IIIa receptor blockers did not differ significantly (p = 0.5) between age subgroups (OR (95% CI) for death or myocardial infarction: 0.86 (0.74 to 0.99), 0.90 (0.80 to 1.02), 0.97 (0.86 to 1.10), 0.90 (0.73 to 1.16); overall 0.91 (0.86 to 0.99). ORs for major bleeding were 1.9 (1.3 to 2.8), 1.9 (1.4 to 2.7), 1.6 (1.2 to 2.1) and 2.5 (1.5–4.1). Overall NNT was 105, and overall NNH was 90. The oldest patients had larger absolute increases in major bleeding, but also had the largest absolute reductions of death or myocardial infarction. Patients ⩾80 years had half of the NNT and a third of the NNH of patients <60 years.
In patients with NSTE‐ACS, the relative reduction of death or non‐fatal myocardial infarction with platelet glycoprotein IIb/IIIa receptor blockers was independent of patient age. Larger absolute outcome reductions were seen in older patients, but with a higher risk of major bleeding. Close monitoring of these patients is warranted.
Historically, drugs prescribed for children have not been studied in pediatric populations. Since 1997, however, a 6-month extension of marketing rights is granted if manufacturers conduct Food and Drug Administration (FDA)-defined pediatric trials. In nearly half the drugs studied, there were unexpected results in dosing, safety, or efficacy compared to adult studies, including failure of half of antihypertensive dose-response trials, which are pivotal for deriving dosing recommendations. We sought to define design elements that might have contributed to these trial failures by combining patient-level data from 6 dose-ranging antihypertensive efficacy trials completed for pediatric exclusivity and submitted to the Food and Drug Administration from 1998–2005. We evaluated dosing, primary endpoint, and other components to assess underlying reasons for failure to show efficacy in children. Of 6 trials examined, 3 showed a dose response; 3 did not. Eligibility criteria were similar across studies, as were subject demographics. Successful studies showed large differences in doses, with little or no overlap between low, medium, and high doses; failed trials used narrow dose ranges with considerable overlap. Successful trials also provided pediatric formulations and used reduction in diastolic, not systolic, blood pressure as the primary endpoint. Careful attention to pediatric pharmacology and selection of primary endpoints can improve trial performance. We found poor dose selection, lack of acknowledgment of differences between adult and pediatric populations, and lack of pediatric formulations to be associated with failures. More importantly, our ability to combine data across trials allowed us to evaluate and potentially improve trial design.
pediatrics; antihypertensive agents; dose-response relationship; clinical trials, randomized; pediatric epidemiology
This study was designed to analyze how patient preferences for survival versus quality of life change after hospitalization with advanced heart failure (HF).
Although patient-centered care is a priority, little is known about preferences to trade length of life for quality among hospitalized patients with advanced HF, and it is not known how those preferences change after hospitalization.
The time trade-off utility, symptom scores, and 6-minute walk were measured at hospitalization and again in 287 patients during 6 months after therapy to relieve congestion in the ESCAPE trial.
Willingness to trade was bimodal. At baseline, the median trade for better quality was 3 months survival time, with modest relation to symptom severity. Preference for survival time was stable for most patients, but increase after discharge occurred in 98/145(68%) patients initially willing to trade survival time, and was more common with symptom improvement, and after therapy guided by pulmonary artery catheters (p=0.034). Adjusting days alive out of hospital for patients’ survival preference reduced overall days by 24%, with largest reduction in patients dying early after discharge (p=0.0015).
Preferences remain in favor of survival for many patients despite advanced HF symptoms, but increase further after hospitalization. The bi-modal distribution and stability of patient preference limit utility as a trial endpoint, but support its relevance in design of care for an individual patient.
heart failure; quality of life; health utilities; hospitalization; cardiomyopathy
In 1997, Congress authorized the Food and Drug Administration (FDA) to grant 6 month extensions of marketing rights through the Pediatric Exclusivity program if industry sponsors complete FDA-requested pediatric trials. The program has been praised for creating incentives for studies in children; it has been criticized as a “windfall” to the innovator drug industry. This critique has been a substantial part of Congressional debate on the program, which is due to sunset in 2007.
To quantify the economic return to industry for completing Pediatric Exclusivity.
Cohort study of programs conducted for Pediatric Exclusivity. We selected 9 drugs that were granted Pediatric Exclusivity. From the final study reports submitted to FDA, we obtained key elements of the clinical trial design and study operations. We estimated the cost of performing each study and converted these into estimates of after-tax cash outflows. We obtained 3-year market sales and converted these into estimates of after-tax cash inflows based upon 6 months of additional market protection. We then calculated the net economic return (cash inflows less outflows) and ratio net return to costs (net economic return divided by cash outflows) for each product.
Main Outcome Measures
Net economic return and ratio of net return to cost.
The indications studied reflected a broad representation of the program: asthma, tumors, attention deficit disorder, hypertension, depression/generalized anxiety disorder, diabetes, gastroesophageal reflux, bacterial infection, and bone mineralization. The distribution of net economic return for 6 months of exclusivity varied substantially among products [net return ranged from (−)$8.9 million to (+)$507.9 million; ratio of return to cost ranged from −0.68 to 73.6]
The economic return for pediatric exclusivity is highly variable. Pediatric Exclusivity, as an incentive to complete much-needed clinical trials in children, can generate lucrative returns, but more frequently produces more modest return on investment.
Much of pediatric drug use is “off-label” because appropriate pediatric studies have not been conducted and the drugs have not been labeled by the US Food and Drug Administration (FDA) for use in children. In 1997, Congress authorized FDA to grant extensions of marketing rights known as “pediatric exclusivity” if FDA-requested pediatric trials were conducted. As a result, there have been over 100 product labeling changes. The publication status of studies completed for pediatric exclusivity has not been evaluated.
To quantify the dissemination of results of studies conducted for pediatric exclusivity into the peer-review literature.
Cohort study of all trials conducted for Pediatric Exclusivity, the subsequent labeling changes, and the publication of those studies in peer-reviewed journals. We categorized each study in the exclusivity application as ”successful” or “unsuccessful” based on FDA approval of the indication sought by the sponsor. We categorized any labeling changes resulting from the studies as ”positive” or “negative” for the drug under study. We then evaluated aspects of the studies and product label changes that were associated with subsequent publication in peer-reviewed medical journals.
Main Outcome Measures
Publication of the trial data in peer-reviewed journals.
Between 1998 and 2004, 253 studies were submitted to FDA for pediatric exclusivity: 50% evaluated efficacy, 20% were multi-dose pharmacokinetic, 13% were single-dose pharmacokinetic, and 17% were safety studies. Labeling changes were positive for 127/253 (50%) of studies; only 112/253 (44%) were published. Efficacy studies and those with a favorable labeling change were more likely to be published. Of 100 studies resulting in important labeling changes, only 33 were published.
The pediatric exclusivity program has been successful in encouraging drug studies in children. However, the dissemination of these results in the peer-reviewed literature is limited. The results of these trials and future studies conducted for pediatric exclusivity should be published in peer-reviewed journals. Mechanisms to more widely disperse this information warrant further evaluation.
registration; children; research; bias
Many clinical trials, including those in pediatric populations, use a placebo arm for medical conditions for which there are readily available therapeutic interventions. Several short-term efficacy trials of antihypertensive medications performed in response to Food and Drug Administration-issued written requests have used a placebo arm; whether the use of a placebo arm is safe in children with hypertension is unknown. We sought to define the rates of adverse events in 10 short-term antihypertensive trials in order to determine whether these trials resulted in increased risk to pediatric patients receiving placebo. We combined patient-level data from 10 antihypertensive efficacy trials performed in pediatric patients that were submitted to the Food and Drug Administration from 1998–2005. We determined the number and type of all adverse events reported during the placebo-controlled portion of the clinical trials and compared these numbers between the patients who received placebo and those who received active drug. Among the 1707 children in the 10 studies, we observed no differences in the rates of adverse events reported between the patients who received placebo and those who received active drug. Only 5 patients suffered a serious adverse event during the trials; none were thought by the investigators to be related to study drug, and only 1 occurred in a patient receiving placebo. Short-term antihypertensive trials in carefully selected populations of hypertensive children can be safely accomplished with the use of a placebo-control arm.
pediatric drug therapy; hypertension; placebo-controlled clinical trials; adverse events; medical ethics
In ESCAPE, there was no difference in days alive and out of the hospital for patients with decompensated heart failure (HF) randomly assigned to therapy guided by pulmonary artery catheter (PAC) plus clinical assessment versus clinical assessment alone. The external validity of these findings is debated.
Methods and Results
ESCAPE sites enrolled 439 patients receiving PAC without randomization in a prospective registry. Baseline characteristics, pertinent trial exclusion criteria, reasons for PAC use, hemodynamics, and complications were collected. Survival was determined from the National Death Index and the Alberta Registry. On average, registry patients had lower blood pressure, worse renal function, less neurohormonal antagonist therapy, and higher use of intravenous inotropes as compared with trial patients. Although clinical assessment anticipated less volume overload and greater hypoperfusion among the registry population, measured filling pressures were similarly elevated in the registry and trial, while measured perfusion was slightly higher among registry patients. Registry patients had longer hospitalization (13 vs. 6 days, p <0.001) and higher 6-month mortality (34% vs. 20%, p < 0.001) than trial patients.
The decision to use PAC without randomization identified a population with higher disease severity and risk of mortality. This prospective registry highlights the complex context of patient selection for randomized trials.
tailored therapy; hemodynamic measurements; outcomes; generalizability; registry
The Food and Drug Administration (FDA) Modernization Act provided for an additional 6-month period of marketing exclusivity to companies that perform pediatric drug trials in response to an FDA-issued written request. Because many safety concerns cannot be detected until after the introduction of a product to a larger and more diverse market, the Best Pharmaceuticals for Children Act required the FDA to report to the Pediatric Advisory Committee (PAC) on adverse events occurring during the 1-year period after granting pediatric exclusivity. We sought to describe the PAC’s recommendations made in response to safety reviews informed by data from the FDA’s Adverse Event Reporting System in 67 drugs granted exclusivity.
Patients and Methods
PAC meetings and data presented by the FDA for all drugs were reviewed from June 2003 through April 2007. We divided the drugs into 2 groups: those that were returned to routine adverse event monitoring and those that had specific PAC recommendations.
Forty-four (65.7%) drugs were returned to routine monitoring for adverse events. The PAC, sometimes working with other advisory committees, recommended label changes for 12 (17.9%) drugs, continued monitoring for 10 (14.9%), production of MedGuides for 9 (13.4%), and an update on label changes resulting from discussions with the sponsor for 1 (1.5%) drug. Some drugs had more than 1 action. Several of the adverse events revealed during this process were rare and life-threatening.
Safety monitoring during the early post-marketing period is crucial to detect rare, serious, or pediatric-specific adverse events. Fortunately, the majority of drugs given exclusivity had no adverse events of a frequency or severity that prevented a return to routine adverse event monitoring.
pediatric drug safety; Pediatric Advisory Committee; adverse event reporting; drug labeling
We determined whether estimated hemodynamics from history and physical examination (H&P) reflect invasive measurements and predict outcomes in advanced heart failure (HF). The role of the H&P in medical decision making has declined in favor of diagnostic tests, perhaps due to lack of evidence for utility.
Methods and Results
We compared H&P estimates of filling pressures and cardiac index with invasive measurements in 194 patients in the ESCAPE trial. H&P estimates were compared with 6-month outcomes in 388 patients enrolled in ESCAPE. Measured right atrial pressure (RAP) was <8 mm Hg in 82% of patients with RAP estimated from jugular veins as <8 mm Hg, and was >12 mm Hg in 70% of patients when estimated as >12 mm Hg. From the H&P, only estimated RAP ≥12 mm Hg (odds ratio [OR] 4.6; P<0.001) and orthopnea ≥2 pillows (OR 3.6; P<0.05) were associated with pulmonary capillary wedge pressure (PCWP) ≥30 mm Hg. Estimated cardiac index did not reliably reflect measured cardiac index (P=0.09), but “cold” versus “warm” profile was associated with lower median measured cardiac index (1.75 vs. 2.0 L/min/m2; P=0.004). In Cox regression analysis, discharge “cold” or “wet” profile conveyed a 50% increased risk of death or rehospitalization.
In advanced HF, the presence of orthopnea and elevated jugular venous pressure are useful to detect elevated PCWP, and a global assessment of inadequate perfusion (“cold” profile) is useful to detect reduced cardiac index. Hemodynamic profiles estimated from the discharge H&P identify patients at increased risk of early events.
history and physical examination; hemodynamics; heart failure