October 2019
Author: Erin Luers
NIH Pragmatic Trials Collaboratory and Living Textbook
The NIH Pragmatic Trials Collaboratory aims to improve the way clinical trials are conducted by creating a new infrastructure for collaborative research with healthcare systems, ultimately ensuring that healthcare providers and patients can make decisions based on the best available clinical evidence. The Collaboratory supports the design and rapid execution of pragmatic clinical trial Demonstration Projects to address questions of major public health importance and engage healthcare delivery systems in research partnerships. The Collaboratory also provides training resources on how to design, conduct, and disseminate embedded pragmatic clinical trials (ePCTs).
Sample size calculation for stepped-wedge cluster-randomized trials with more than two levels of clustering
April 24, 2019
This paper provides power and sample size methods for stepped-wedge trials with more than two levels (subjects within clusters), and illustrates these methods in the settings of the CHANGE trial–which randomizes nursing homes (level 4) consisting of nursing home wards (level 3) in which nurses (level 2) are observed with respect to their hand hygiene compliance during hand hygiene opportunities (level 1) in the care of patients.
Abstract
Background/Aims: Power and sample size calculation formulas for stepped-wedge trials with two levels (subjects within clusters) are available. However, stepped-wedge trials with more than two levels are possible. An example is the CHANGE trial which randomizes nursing homes (level 4) consisting of nursing home wards (level 3) in which nurses (level 2) are observed with respect to their hand hygiene compliance during hand hygiene opportunities (level 1) in the care of patients. We provide power and sample size methods for such trials and illustrate these in the setting of the CHANGE trial.
Methods: We extend the original sample size methodology derived for stepped-wedge trials based on a random intercepts model, to accommodate more than two levels of clustering. We derive expressions that can be used to determine power and sample size for p levels of clustering in terms of the variances at each level or, alternatively, in terms of intracluster correlation coefficients. We consider different scenarios, depending on whether the same units in a particular level are repeatedly measured as a cohort sample or whether different units are measured cross-sectionally.
Results: A simple variance inflation factor is obtained that can be used to calculate power and sample size for continuous and by approximation for binary and rate outcomes. It is the product of (1) variance inflation due to the multilevel structure and (2) variance inflation due to the stepped-wedge manner of assigning interventions over time. Standard and non-standard designs (i.e. so-called “hybrid designs” and designs with more, less, or no data collection when the clusters are all in the control or are all in the intervention condition) are covered.
Conclusions: The formulas derived enable power and sample size calculations for multilevel stepped-wedge trials. For the two-, three-, and four-level case of the standard stepped wedge, we provide programs to facilitate these calculations.
LTC Focus
LTCFocus.org provides data on nursing home care in the US. Their goal is to allow researchers to trace relationships between state policies, local market forces, and the quality of long-term care, enabling policymakers to craft state and local guidelines that promote high-quality, cost-effective, equitable care for older Americans.
Public Attitudes toward Consent When Research Is Integrated into Care—Any “Ought” from All the “Is”?
IMPACT Collaboratory Announces the 2022-2023 Faculty Scholars
The IMPACT Collaboratory is pleased to announce the 2022 IMPACT Faculty Scholars.
This program aims to enhance the career development of investigators in the design and conduct of embedded pragmatic clinical trials for people living with dementia and their care partners by integrating them into the activities of our Cores and Teams. Faculty Scholars attend monthly Core meetings, are mentored by an IMPACT executive committee member, engage in scholarly projects to enrich career development, and attend Collaboratory-wide events including Training Workshops and the Annual Business Meeting and Scientific Conference. Throughout the year, faculty participate in monthly Grand Rounds and quarterly Research-in-Progress seminars in addition to other opportunities for career development, training, and networking. Faculty Scholars are nominated by IMPACT members.
The 2022-2023 IMPACT Faculty Scholars:
- Talha Ali, PhD, Tufts University
- Rupak Datta, MD, PhD, Yale School of Medicine
- Chanee Fabius, PhD, Johns Hopkins Bloomberg School of Public Health
- Shekinah Fashaw-Walters, MPH, PhD, University of Minnesota School of Public Health
- Cameron Gettel, MD, Yale School of Medicine
- Natalia Gouskova, PhD, Hebrew SeniorLife’s Hinda and Arthur Marcus Institute for Aging Research
- Ying-Ling Jao, PhD, RN, Pennsylvania State University
- Zachary Kunicki, PhD, Warren Alpert Medical School of Brown University
- Kylie Meyer, PhD, Case Western Reserve University School of Nursing
- Karen Moss, PhD, RN, CNL, The Ohio State University Colleges of Nursing and Medicine
- Evan Plys, PhD, University of Colorado School of Medicine
- Sandra Shi, MD, Hebrew SeniorLife’s Hinda and Arthur Marcus Institute for Aging Research
- Mark Toles, PhD, RN, University of North Carolina at Chapel Hill School of Nursing
IMPACT Collaboratory Announces Recipients of Two Funding Mechanisms: Demonstration Projects and Pilot Grants
The NIA IMPACT Collaboratory is pleased to announce the awardees of the Demonstration Projects Program Cycle 2 and the Pilot Grants Program Cycle 3B. Awardees of these opportunities will be supported by IMPACT’s Cores and Teams to conduct embedded pragmatic clinical trials (ePCTs) of non-pharmacological interventions within healthcare systems to improve care for people living with Alzheimer’s disease and Alzheimer’s disease related dementias (AD/ADRD) and their care partners. The IMPACT Collaboratory prioritizes applications that promote health equity and address dementia care for people of all backgrounds. Learn more about IMPACT Collaboratory funding opportunities and general information on the website. Read more about these opportunities and our newest awardees below.
Demonstration Projects Program Cycle 2
The Demonstration Projects Program is a funding mechanism developed to support full-scale, Stage IV effectiveness ePCTs (based on the NIH Stage Model) that test non-pharmacological interventions for people living with AD/ADRD and their care partners embedded within and linked to the needs of a health care system. The goal of Demonstration Projects is to generate evidence on effective care delivery practices that can be expanded and/or implemented in other systems. The intervention typically includes relatively simple system changes, direct patient outreach, or successfully piloted programs ready for testing at scale.
Cycle 2 recipients are:
- Ira Hofer, MD, Icahn School of Medicine, and Susana Vacas, MD, PhD, Massachusetts General Hospital, Harvard Medical School
Mitigation of Postoperative Delirium in High-Risk Patients - Lisa Kern, MD, MPH, Weill Cornell Medicine
Improving How People Living with Dementia are Selected for Care Coordination: A Pragmatic Clinical Trial Embedded in an Accountable Care Organization
Pilot Grant Program Cycle 3B
The Pilot Grant Program funds several one-year pilots for ePCTs that test non-pharmacological interventions embedded in health care system(s) to improve care for people living with AD/ADRD and their care partners. Pilot studies are conducted to generate the preliminary data necessary to design and conduct future full-scale Stage IV effectiveness ePCT (based on the NIH Stage Model) that will be funded through other grant mechanisms (National Institutes of Health or other sources).
Cycle 3B recipients are:
- Jennifer Carnahan, MD, MPH, MA, Indiana University School of Medicine
Embedded Clinical Trial of Patient Priorities Care Among People Living with Mild Cognitive Impairment and Dementia - Helen Kales, MD, University of California, Davis
Reducing Inappropriate Medication use for Behavioral and Psychological Symptoms of Dementia and Improving Health Outcomes in People Living with Dementia - Donovan Maust, MD, MS, University of Michigan
A Patient-Facing Tool to Reduce Opioid, Psychotropic Polypharmacy in People Living With Dementia - Elizabeth Phelan, MD, MS, University of Washington
Deprescribing to Reduce Injurious Falls among Older Adults with Dementia (STOP-FALLS-D)