Methods for safety and endpoint ascertainment: identification of adverse events through scrutiny of negatively adjudicated events.

BACKGROUND: The primary goal of phase 2 and 3 clinical trials is to evaluate the safety and effectiveness of therapeutic interventions, and efficient and reproducible ascertainment of important clinical events, either as clinical outcome events (COEs) or adverse events (AEs), is critical. Clinical outcomes require consistency and clinical judgment, so these events are often adjudicated centrally by clinical events classification (CEC) physician reviewers using standardized definitions. In contrast, AEs are reported by sites to the trial coordinating center based on common reporting criteria set by regulatory authorities and trial sponsors. These different requirements have led to the development of separate tracks for COE and AE review. MAIN BODY: Potential COEs that fail to meet standardized definitions for CEC adjudication - i.e. negatively adjudicated events (NAE) - may meet criteria for AEs. Trial oversight practices require the sponsor to process AEs regardless of how the AEs are submitted; therefore, review of NAEs may be necessary to ensure that important AEs do not go unreported. The Duke Clinical Research Institute (DCRI) developed and implemented a process for scrutinizing NAEs to detect potential missed serious AEs. Initial experience with this process across two trials suggests that approximately 0.2% of NAEs are serious unexpected AEs that were not otherwise reported and another 1.5% are serious expected AEs. CONCLUSIONS: Given their infrequent concealment of serious AEs in two large trials assessing cardiovascular outcomes, routine scrutiny of NAEs to identify AEs is not recommended at this time, though it may be useful in some trials and should be carefully considered by the trial team. Closer integration of data across safety surveillance and endpoint adjudication systems may enable scrutiny of NAEs when indicated while limiting complexity associated with this process.

Reporting Clinical End Points and Safety Events in an Acute Coronary Syndrome Trial: Results With Integrated Collection.

BACKGROUND: End points and adverse events (AEs) are collected separately in clinical trials, yet regulatory requirements for serious AE reporting vary across regions, so classifying end points according to seriousness criteria can be useful in global trials. METHODS AND RESULTS: In the Apixaban for Prevention of Acute Ischemic Events 2 (APPRAISE-2) trial, patients with a recent acute coronary syndrome were randomized to apixaban or placebo for the prevention of recurrent ischemic events. Suspected end points (myocardial infarction, stroke, or bleeding) were adjudicated by an independent clinical events classification committee. Safety criteria were collected for suspected end points and AEs. Patient-level event rates per 100 patient-days of follow-up, modeled using Poisson regression, explored the influence of region and patient characteristics on event reporting. Overall, 13 909 events were reported by 858 sites in 39 countries; 8.4% (n=1166) were suspected end points, and 91.6% (n=12 743) were AEs. Overall, 66.0% of suspected end points were confirmed by the clinical events classification committee. Most clinical events classification committee-confirmed end points met criteria to be classified as serious (94.0%); many clinical events classification committee-negated end points also did (63.2%), but fewer AEs met seriousness criteria (17.9%). The most common seriousness criterion was hospitalization (79.9%, n=2594). Region explained 28.7% of end point- and 26.4% of serious AE-reporting variation, and patient characteristics explained an additional 25.4% of end point and 13.4% of serious AE variation. Nonserious AE-reporting variation was not explained by adjustment. CONCLUSIONS: An integrated collection of end points and serious AEs is feasible in a multinational trial and illustrates the shared characteristics of events. Tailoring event collection to fit the phase and purpose of the trial is achievable and informative. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifier: NCT00831441.

Pooled analysis of adverse event collection from 4 acute coronary syndrome trials.

BACKGROUND: Adverse event collection in randomized clinical trials establishes drug safety. Although costly and regulated, it is rarely studied. METHODS: Adverse event data from 4 clinical trials (APPRAISE-2, PLATO, TRACER, TRILOGY ACS) comprising 48,118 participants with acute coronary syndromes were pooled to compare patterns and determinants of reporting. Events were classified as serious (SAE) or nonserious (AE) from hospital discharge to 1 year; study end points were excluded. RESULTS: In total, 84,901 events were reported. Of those, 12,266 (14.4%) were SAEs and 72,635 (85.6%) were AEs. Of all participants, 7,823 (16.3%) had SAEs, 18,124 (37.7%) had only AEs, and 22,171 (46.1%) had neither. Nonserious adverse events were distributed across system organ classes: general disorders (11%), infection (10%), gastrointestinal (10%), respiratory (9%), cardiovascular (8.4%), and other (35%). Serious adverse events had a higher proportion of cardiovascular causes (14.0%). Event reporting was highest after hospital discharge, decreasing rapidly during the following 3 months. In a Cox proportional hazards model, chronic obstructive pulmonary disease (hazard ratio 1.58, 95% CI 1.44-1.74), heart failure (1.55, 1.40-1.70), older age, and female sex were independent predictors of more SAEs, whereas enrollment in Eastern Europe (0.63, 0.58-0.69) or Asia (0.84, 0.75-0.94) were independent predictors of fewer SAEs. CONCLUSIONS: Half of all participants reported adverse events in the year after acute coronary syndrome; most were AEs and occurred within 3 months. The high volume of events, as well as the variation in SAE reporting by characteristics and enrollment region, indicates that efforts to refine event collection in large trials are warranted.

Clinical effectiveness of coronary stents in elderly persons: results from 262,700 Medicare patients in the American College of Cardiology-National Cardiovascular Data Registry.

OBJECTIVES: The aim of this study was to compare outcomes in older individuals receiving drug-eluting stents (DES) and bare-metal stents (BMS). BACKGROUND: Comparative effectiveness of DES relative to BMS remains unclear. METHODS: Outcomes were evaluated in 262,700 patients from 650 National Cardiovascular Data Registry sites during 2004 to 2006 with procedural registry data linked to Medicare claims for follow-up. Outcomes including death, myocardial infarction (MI), revascularization, major bleeding, stroke, death or MI, death or MI or revascularization, and death or MI or stroke were compared with estimated cumulative incidence rates with inverse probability weighted estimators and Cox proportional hazards ratios. RESULTS: The DES were implanted in 217,675 patients and BMS were implanted in 45,025. At 30 months, DES patients had lower unadjusted rates of death (12.9% vs. 17.9%), MI (7.3 of 100 patients vs. 10.0 of 100 patients), and revascularization (23.0 of 100 patients vs. 24.5 of 100 patients) with no difference in stroke or bleeding. After adjustment, DES patients had lower rates of death (13.5% vs. 16.5%, hazard ratio [HR]: 0.75, 95% confidence interval [CI]: 0.72 to 0.79, p < 0.001) and MI (7.5 of 100 patients vs. 8.9 of 100 patients, HR: 0.77, 95% CI: 0.72 to 0.81, p < 0.001), with minimal difference in revascularization (23.5 of 100 patients vs. 23.4 of 100 patients; HR: 0.91, 95% CI: 0.87 to 0.96), stroke (3.1 of 100 patients vs. 2.7 of 100 patients, HR: 0.97, 95% CI: 0.88 to 1.07), or bleeding (3.4 of 100 patients vs. 3.6 of 100 patients, HR: 0.91, 95% CI: 0.84 to 1.00). The DES survival benefit was observed in all subgroups analyzed and persisted throughout 30 months of follow-up. CONCLUSIONS: In this largest ever real-world study, patients receiving DES had significantly better clinical outcomes than their BMS counterparts, without an associated increase in bleeding or stroke, throughout 30 months of follow-up and across all pre-specified subgroups.

Comparing classifications of death in the Mode Selection Trial: agreement and disagreement among site investigators and a clinical events committee.

Clinical events committees (CECs) are the current standard for endpoint adjudication in clinical trials. However, little data exist with which to compare CEC and site investigator determinations or to evaluate internal agreement among CEC members. Using data from the Mode Selection Trial in Sinus Node Dysfunction (MOST), we analyzed classifications of death in order to compare internal agreement among CEC physician reviewers and agreement between the CEC and site investigators. Death was classified at 2 levels: by major cause (cardiac, noncardiac, or unknown) and by minor subclassification of the major classifications. Reviewer agreement was tabulated at the major and minor levels, and standard and weighted kappa statistics were calculated. Disagreement at both levels was also determined. Individual decision-making was tabulated in terms of frequency in classifying death as unknown. All 404 deaths were classified by the CEC. Site investigators determined major classifications in 382 cases and minor classification in 379 cases. The CEC and the site investigators disagreed in classifying 41 cases (10.7%) at the major level and 117 (30.9%) at the minor level. CEC reviewers disagreed internally at the major level in 64 cases (15.8%), at the minor level in 63 cases (15.6%), and at any level in 127 cases (31.4%) (kappa = 0.60, 95% confidence interval (CI) [0.55, 0.66]; weighted kappa = 0.66, 95% CI [0.62, 0.75]). In resolving internal disagreements, the full CEC agreed with 1 of 2 CEC reviewers in 85.9% of cases. Disagreements occurred between site investigators and CEC reviewers in classifying deaths. Endpoint determination and decision-making varied among individual CEC reviewers, but second-tier reviews by the full CEC resolved all disagreements. These findings support continued use of CECs for endpoint adjudication in clinical trials.