Initially interested in both longitudinal epidemiologic studies and clinical trials, Dr. Lynda Powell ultimately turned her attention primarily to behavioural clinical trials. Her projects aim to contribute to our understanding of how to conduct behavioural trials, from design and implementation to analysis, interpretation, and progression.
Overcoming the Challenges Collaboratively
After spending a few years aimlessly teaching public school and serving as a university counselor, Powell was offered the opportunity to work on one of the first behavioural clinical trials ever conducted: The Recurrent Coronary Prevention Project. When results showed a 44% reduction in the cardiovascular recurrence rate in coronary patients with Type A behaviour, Powell was hooked. Her passion for incorporating behavioural treatments into regular medical care has guided her career ever since. “Getting a taste of behavioural clinical trials was like sipping a white Burgundy wine for the first time,” she explains, “there was no going back.”
Today her time is divided between departmental administrative duties —which includes mentoring department faculty and acting as liaison with senior leadership— and her research which involves leading a variety of research teams. Suffice it to say that on most days, Powell is “in a meeting” as virtually all of her work pivots around collaborating with others.
In fact, according to Powell, working with others plays a particularly critical role in her research. The importance of the team is paramount. Powell speaks highly of the expertise of her colleagues in Rush University’s Department of Preventive Medicine, including experts in behavioural clinical trials from the fields of medicine, psychology, biostatistics, and clinical trials, and independent core personnel in their Data Management Centre who develop, implement and analyze trial data, and an independent administrative core that supports capacity in submitting, reporting, and ensuring trial quality control.
Yet, while she acknowledges that behavioural researchers spend a lot of time sharing with one another, she believes that not enough time is spent trying to understand advances in basic science that could strengthen behavioural interventions. Similarly, she believes more effort is needed in interfacing with medical practitioners to better understand the challenges they face in their practice, and explore how behavioural interventions could help meet these challenges. She believes the best advances will come from “networking more across disciplines, and less inside our own.”
Building on Past Successes
The theoretical frameworks that guide all this collaborative research are based in theories about how to generate sustained change. As a graduate student at Stanford, Powell was mentored by Al Bandura, and her work today is guided by social-cognitive theory as well as self-determination theory. More recently, she has found new guidance in the principles of habit modification from the field of neuroscience (where studies have shown that inappropriate eating behaviours are not a question of self-control but instead about the persistence of habits). She has also recently begun embracing mindfulness practices as ways to reduce the appeal of temptations and desires in patients struggling with lifestyle challenges such as unhealthy eating, chronic stress, and sedentary living.
Powell is perhaps most well-known for leading the ORBIT consortium alongside department and institution colleagues and different consortia sites which led to the development of the ORBIT model for behavioural treatment development. (View summary of ORBIT model)
After recently completing two large-scale projects (a dual-level NHLBI-funded P50 Disparities Centre intervention aimed at reducing repeated hospitalization in African American patients with heart failure — an innovative design that is not yet well understood — and an NHLBI-funded U01 mechanism aimed at developing an intervention to prevent the progression of visceral fat in women traversing into menopause), Powell is now preparing a new and ambitious multi-site behavioural clinical trial aimed at determining the effectiveness of a lifestyle intervention to achieve sustained remission of the metabolic syndrome. More meetings lie ahead for Powell as the project will bring together six national American sites and its role will be to offer leadership for both the trial and its data management. The trial is set to begin in 2018.
On the Larger Horizon
Powell believes that the field of behavioural medicine should push toward rigorous evaluation of behavioural treatments in behavioural efficacy and effectiveness trials. Currently, she believes, the field tends to stop at conducting behavioural trials on behavioural or surrogate outcomes. Her current projects aim to use models that steer toward efficacy trials. She feels this is a particularly important direction to explore, particularly for junior-level investigators.
Powell is perhaps most excited about the advent of precision lifestyle medicine — that is, gearing behavioural interventions to those most likely to benefit from them. “We need to spend more time developing behavioural treatments, and tinkering with them to potentiate their strength,” explains Powell. This also means having to rethink our commitment to the generalizability of interventions to a wide range of people with diseases of interest. She believes that a patient-centred approach means offering interventions to patient subgroups who are ready to fully engage with them. “If only 50% of an at-risk population adheres to a pharmacological treatment,” she asks, “why should we expect 100% adherence to our behavioural treatments?”
She explains further by referring to a meta-analysis (Naci & Ionnidis 2015 in British Journal of Sports Medicine) comparing drug and exercise intervention approaches toward reducing cardiovascular recurrences. Whereas both approaches had the same level of efficacy, of the 305 trials reviewed, 81% investigated drug interventions but only 19% investigated exercise interventions, and of the 339,274 patients included in this review, 96% were involved in drug trials but only 4% were involved in exercise trials. No one is surprised, then, that patients are immediately administered drugs after a heart attack rather than being offered lifestyle treatments. “We are simply not doing enough behavioural trials,” concludes Powell, and her upcoming book emphasizes that quantity is nothing without the corresponding quality.
Promoting the Science of Behavioural Clinical Trials for Chronic Diseases
To wit, Powell has been collaborating with IBTN Founding Member Dr. Kenneth Freedland and Dr. Peter Kaufmann on a new book due entitled “The Science of Behavioral Clinical Trials for Chronic Diseases” (Springer, 2018). The book will cover the anatomy and development of a behavioural trial, including the choice of comparator, and will discuss the importance of hypothesized pathways by which behavioural treatments can translate into primary clinical endpoints. Chapters will also be devoted to issues of feasibility, pilot studies, protection of randomization, measurement of outcomes, and the all-important hurdle of clinical significance, not to mention the tricky task of investigator equipoise.
With the true voice of mentors, Powell and her colleagues offer guidance to the future of the field in the book’s introduction:
“An understanding of the mistakes made in the past can foster a richer understanding of how to make decisions in the present and plans for the future. We do not want new investigators to follow in our footsteps. We want them to seek what we sought but in ways that are better informed, more sophisticated, and more successful. We want to pass to them a lighter gavel than the one we received. We are cheerleaders for their success.”
Powell’s ability to translate the impact of this work to junior researchers, and non-researchers alike, underscores the skills she has acquired over the course of her career to communicate the goals of the work that continues to impassion her and her colleagues. At the end of the day, it’s about understanding how to determine if a treatment approach actually works in order to promote it in practice. Though there are salient differences between pharmacological trials and behavioural trials, rigorous evaluation of efficacy and effectiveness is what they must ultimately share. According to Powell, we need to push the development of behavioural interventions “with the methodological purity we see on the medical side. They are the gatekeepers.”
Dr. Powell will be attending the 2018 IBTN Conference in Montréal in May, as well as meetings of the Society for Behavioural Medicine, the International Congress of Behavioural Medicine, and the Academy of Behavioural Medicine Research.
The NIH’s ORBIT’s model is a comprehensive and structured framework used to develop and then test new behavioural interventions. It parallels frameworks used by the pharmaceutical industry, including basic social science, behavioural research, and phases I-IV. The framework is fluid in that it can move forwards and backwards depending on progress and results. Formally published in 2015, the main paper has become a cornerstone for the field of behavioural medicine.
- Begin with the “end” in mind
- Process is guided by “significant clinical questions” from end users (patients, providers)
- Progression from basic to more clinical/applied stages
- Pushes toward the efficacy trial
- Each phase includes “clinically meaningful” milestones
- Specify a priori criteria for moving to next phase of the intervention development process
- Emphasis is on achieving “clinically significant” (not just statistically significant) change in behavioural targets
- Flexibility in terms of:
- Number & types of studies within phases
- Duration of each phase
- Movement from one phase to the next (can “skip” a phase if necessary)
- Flow is bidirectional
- Allows for “failure” and return to earlier phases as needed
Dr. Lynda H. Powell is the Charles J. and Margaret Roberts Professor of Preventive Medicine, Medicine (Cardiology), Behavioral Sciences, and Pharmacology and Chairman, Department of Preventive Medicine and Rush University Medical Center. Her research specializes in the behavioural treatment development and behavioural randomized clinical trials to promote cardiometabolic health. Dr. Powell has been the Principal Investigator of six major randomized behavioural clinical trials and a founding faculty member and former Co-Director of the NIH-OBSSR Summer Institute on Behavioral Clinical trials, now in its seventeenth year. Dr. Powell was a Principal Investigator of the NIH-funded ORBIT network which included 7 sites all of whom were in the process of developing behavioural interventions for obesity and created the ORBIT model for behavioural treatment development from the experiences of the ORBIT.