Correction to: Cluster identification, selection, and description in Cluster randomized crossover trials: the PREP-IT trials

An amendment to this paper has been published and can be accessed via the original article

Use of Calcium Channel Blockers and Breast Cancer Risk in the Women's Health Initiative

Background: Use of calcium channel blockers (CCBs) has been associated with increased risk of breast cancer in some, but not all, studies. Differences in reported associations from prior studies may be due, in part, to inadequate control of confounding factors.Methods: Participants were 28,561 postmenopausal women from the Women's Health Initiative who reported use of either CCBs or other antihypertensive medications (AHMs) at baseline; 1,402 incident breast cancer cases were diagnosed during 12 years of follow-up. Adjusted Cox regression models were used to estimate HRs and 95% confidence intervals (CI) for the associations between CCB use relative to other AHM use and breast cancer risk.Results: Use of CCBs was not associated with breast cancer risk (HR, 1.06; 95% CI, 0.94-1.20) relative to use of other AHMs. Associations approximated the null value when CCBs were considered by duration of use, length of action, or drug class.Conclusions: We provide additional evidence that CCBs do not influence breast cancer risk in postmenopausal women.Impact: The results from this study, which includes strong control for potential confounding factors, cast doubt on increases in risk with CCBs. Cancer Epidemiol Biomarkers Prev; 26(8); 1345-8. ©2017 AACR

PREVENTion of CLots in Orthopaedic Trauma (PREVENT CLOT): a randomised pragmatic trial protocol comparing aspirin versus low-molecular-weight heparin for blood clot prevention in orthopaedic trauma patients.

IntroductionPatients who sustain orthopaedic trauma are at an increased risk of venous thromboembolism (VTE), including fatal pulmonary embolism (PE). Current guidelines recommend low-molecular-weight heparin (LMWH) for VTE prophylaxis in orthopaedic trauma patients. However, emerging literature in total joint arthroplasty patients suggests the potential clinical benefits of VTE prophylaxis with aspirin. The primary aim of this trial is to compare aspirin with LMWH as a thromboprophylaxis in fracture patients.Methods and analysisPREVENT CLOT is a multicentre, randomised, pragmatic trial that aims to enrol 12 200 adult patients admitted to 1 of 21 participating centres with an operative extremity fracture, or any pelvis or acetabular fracture. The primary outcome is all-cause mortality. We will evaluate non-inferiority by testing whether the intention-to-treat difference in the probability of dying within 90 days of randomisation between aspirin and LMWH is less than our non-inferiority margin of 0.75%. Secondary efficacy outcomes include cause-specific mortality, non-fatal PE and deep vein thrombosis. Safety outcomes include bleeding complications, wound complications and deep surgical site infections.Ethics and disseminationThe PREVENT CLOT trial has been approved by the ethics board at the coordinating centre (Johns Hopkins Bloomberg School of Public Health) and all participating sites. Recruitment began in April 2017 and will continue through 2021. As both study medications are currently in clinical use for VTE prophylaxis for orthopaedic trauma patients, the findings of this trial can be easily adopted into clinical practice. The results of this large, patient-centred pragmatic trial will help guide treatment choices to prevent VTE in fracture patients.Trial registration numberNCT02984384

PREVENTion of CLots in Orthopaedic Trauma (PREVENT CLOT): a randomised pragmatic trial protocol comparing aspirin versus low-molecular-weight heparin for blood clot prevention in orthopaedic trauma patients

Introduction Patients who sustain orthopaedic trauma are at an increased risk of venous thromboembolism (VTE), including fatal pulmonary embolism (PE). Current guidelines recommend low-molecular-weight heparin (LMWH) for VTE prophylaxis in orthopaedic trauma patients. However, emerging literature in total joint arthroplasty patients suggests the potential clinical benefits of VTE prophylaxis with aspirin. The primary aim of this trial is to compare aspirin with LMWH as a thromboprophylaxis in fracture patients.Methods and analysis PREVENT CLOT is a multicentre, randomised, pragmatic trial that aims to enrol 12 200 adult patients admitted to 1 of 21 participating centres with an operative extremity fracture, or any pelvis or acetabular fracture. The primary outcome is all-cause mortality. We will evaluate non-inferiority by testing whether the intention-to-treat difference in the probability of dying within 90 days of randomisation between aspirin and LMWH is less than our non-inferiority margin of 0.75%. Secondary efficacy outcomes include cause-specific mortality, non-fatal PE and deep vein thrombosis. Safety outcomes include bleeding complications, wound complications and deep surgical site infections.Ethics and dissemination The PREVENT CLOT trial has been approved by the ethics board at the coordinating centre (Johns Hopkins Bloomberg School of Public Health) and all participating sites. Recruitment began in April 2017 and will continue through 2021. As both study medications are currently in clinical use for VTE prophylaxis for orthopaedic trauma patients, the findings of this trial can be easily adopted into clinical practice. The results of this large, patient-centred pragmatic trial will help guide treatment choices to prevent VTE in fracture patients.Trial registration number NCT02984384

Building a Clinical Research Network in Trauma Orthopaedics: The Major Extremity Trauma Research Consortium (METRC)

OBJECTIVESLessons learned from battle have been fundamental to advancing the care of injuries that occur in civilian life. Equally important is the need to further refine these advances in civilian practice, so they are available during future conflicts. The Major Extremity Trauma Research Consortium (METRC) was established to address these needs.METHODSMETRC is a network of 22 core level I civilian trauma centers and 4 core military treatment centers-with the ability to expand patient recruitment to more than 30 additional satellite trauma centers for the purpose of conducting multicenter research studies relevant to the treatment and outcomes of orthopaedic trauma sustained in the military. Early measures of success of the Consortium pertain to building of an infrastructure to support the network, managing the regulatory process, and enrolling and following patients in multiple studies.RESULTSMETRC has been successful in maintaining the engagement of several leading, high volume, level I trauma centers that form the core of METRC; together they operatively manage 15,432 major fractures annually. METRC is currently funded to conduct 18 prospective studies that address 6 priority areas. The design and implementation of these studies are managed through a single coordinating center. As of December 1, 2015, a total of 4560 participants have been enrolled.CONCLUSIONSSuccess of METRC to date confirms the potential for civilian and military trauma centers to collaborate on critical research issues and leverage the strength that comes from engaging patients and providers from across multiple centers

Implementing stakeholder engagement to explore alternative models of consent: An example from the PREP-IT trials

Introduction: Cluster randomized crossover trials are often faced with a dilemma when selecting an optimal model of consent, as the traditional model of obtaining informed consent from participant's before initiating any trial related activities may not be suitable. We describe our experience of engaging patient advisors to identify an optimal model of consent for the PREP-IT trials. This paper also examines surrogate measures of success for the selected model of consent. Methods: The PREP-IT program consists of two multi-center cluster randomized crossover trials that engaged patient advisors to determine an optimal model of consent. Patient advisors and stakeholders met regularly and reached consensus on decisions related to the trial design including the model for consent. Patient advisors provided valuable insight on how key decisions on trial design and conduct would be received by participants and the impact these decisions will have. Results: Patient advisors, together with stakeholders, reviewed the pros and cons and the requirements for the traditional model of consent, deferred consent, and waiver of consent. Collectively, they agreed upon a deferred consent model, in which patients may be approached for consent after their fracture surgery and prior to data collection. The consent rate in PREP-IT is 80.7%, and 0.67% of participants have withdrawn consent for participation. Discussion: Involvement of patient advisors in the development of an optimal model of consent has been successful. Engagement of patient advisors is recommended for other large trials where the traditional model of consent may not be optimal