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A data safety monitoring board (DSMB) established in a phase III trial to monitor the safety of participants in a clinical trial views itself as protecting participants and ensuring the integrity of the study. The DSMB should operate under a clear charter, with expectations understood by all members of the Board, the sponsor, and the investigators. Sponsors must trust their DSMBs. The sponsor must give the DSMB the tools and the data that it needs to operate effectively in protecting the safety of the participants.

We fit a mixed effects logistic regression model to longitudinal adverse event (AE) severity data (four-point ordered categorical response) to describe the dose-AE severity response for an investigational drug. The distribution of the predicted interindividual random effects (Bayes predictions) was extremely bimodal. This extreme bimodality indicated that biased parameter estimates and poor predictive performance were likely. The distribution's primary mode was composed of patients that did not experience an AE. Moreover, the Bayes predictions of these non-AE patients were nearly degenerative, i.e., the predictions were nearly identical. To resolve this extreme bimodality we propose using a two-part mixture modeling approach. The first part models the incidence of AE's, and the second part models the severity grade given the patient had an AE. Unconditional probability predictions are calculated by mixing the incidence and severity model probability predictions. We also report results of simulation studies, which assess the predictive and statistical (bias and precision) performance of our approach.

During phase III clinical trials in life-threatening disease settings, it is important to ensure that the Data Monitoring Committee (DMC) has exclusive access to the interim efficacy and safety data generated by the data analysis centre, in order to minimize the risk of widespread prejudgement of unreliable trial results based on limited data. This prejudgement could adversely impact rates of patient accrual, continued adherence to trial regimens and ability to obtain unbiased and complete assessment of trial outcome measures. This also could result in publications of early results that might be very inconsistent with final study data on the benefit-to-risk profile of the study interventions. Circumstances arise only rarely in which unblinding of interim data beyond the DMC would enhance the ability of the trial to provide reliable results. However, to address the ethical imperative to protect the interests of study participants, the DMC itself should have access to unblinded efficacy and safety results., (Copyright 2002 John Wiley & Sons, Ltd.)

Background: It has not been clearly demonstrated whether HIV vaccination can complicate routine HIV testing. In this report, we describe the laboratory data of two prisoners who received rgp120 vaccine in a phase III trial underway in Thailand. These data indicate that previous vaccination may complicate the interpretation of screening HIV diagnostic tests., Case Presentation: The participants were identified from a cohort study on "Health factors related to HIV-1 and other viral infections among incarcerated people" that was approved by The Ethical Committee for Research in Human Subjects, Ministry of Public Health, Thailand. HIV diagnosis was definitively established with serial specimens using multi-screening tests, Western blot and diagnostic PCR.Anti-HIV screening tests consistently exhibited either weakly reactive or inconclusive results. The band patterns of the Western blot analysis corresponded to those found in individuals who received the rgp120 vaccination. Definite results were established using diagnostic PCR, which exhibited consistently negative results with follow-up specimens. Such problems in HIV testing are not easily resolved in the routine clinical setting in Thailand., Conclusions: These data demonstrate that HIV-1 vaccination interferes with routine diagnostic tests. Similar cases will not be uncommon in Thailand, where 2,545 people have already participated in a phase III trial.

Efficacy trials of candidate HIV-1 vaccines require study populations at high risk of infection who adhere to study protocols and who are willing to participate. Data from HIV-1 antibody-negative men (n = 698) enrolled in Project ACHIEVE in New York City were analyzed to assess willingness to participate in efficacy trials, factors influencing willingness, and the effect on willingness of the June 1994 media events about the decision not to proceed with phase III trials and about breakthrough infections during phase I and II vaccine trials. Sixty-eight percent indicated they would definitely or probably be willing to participate. Men enrolled during the time of media events were significantly less willing compared with men enrolled during other periods. These men were also more likely to mention safety of the vaccine, fear or mistrust of research or government, and social risks as important factors in their decision compared with men enrolled during other periods. The most frequently cited motivator for participation was altruism (57%); the most frequently cited barriers were vaccine safety (36%) and vaccine-induced seropositivity (19%). A substantial proportion of this cohort was willing to participate in future vaccine efficacy trials. However, because willingness may be affected by issues of vaccine safety, vaccine-induced seropositivity, and media coverage of these issues, significant efforts are needed for participant and community education, and specific concerns must be addressed in the design and implementation of trials.

Purpose: Here we report the results of a randomized study undertaken to test the efficacy of a supplementary, telephone-based nursing intervention in increasing patients' awareness and understanding of the clinical trials in which they are asked to participate., Methods: During a 12-month period, 180 cancer patients who were approached to participate in a phase II or III clinical trial were randomized to undergo either of the following: (1) standard informed consent procedures based on verbal explanations from the treating physician plus written information (controls); or (2) standard informed consent procedures plus a supplementary, telephone-based contact with an oncology nurse (intervention). For purposes of evaluation, face-to-face interviews were conducted with all patients approximately 1 week after the informed consent process had been completed., Results: The two groups were comparable with regard to sociodemographic and clinical variables. Both groups had a high level of awareness of the diagnosis and of the nature and objectives of the proposed treatments. The intervention group was significantly (P < .01) better informed about the following: (1) the risks and side effects of treatment; (2) the clinical trial context of the treatment; (3) the objectives of the clinical trial; (4) where relevant, the use of randomization in allocating treatment; (5) the availability of alternative treatments; (6) the voluntary nature of participation; and (7) the right to withdraw from the clinical trial. The intervention did not have any significant effect on patients' anxiety levels or on rates of clinical trial participation. Patients reported high levels of satisfaction with the intervention., Conclusion: The use of a supplementary, telephone-based nursing intervention is a feasible and effective means to increase cancer patients' awareness and understanding of the salient issues that surround the clinical trials in which they are asked to participate.