Do you know the difference between an explanatory and a pragmatic clinical trial? Many researchers are familiar with explanatory clinical trials, which look at the effectiveness of a particular intervention to improve health in a controlled setting. But what makes a clinical trial pragmatic?
Pragmatic trials may test the same intervention as an explanatory trial, but they are conducted in real-world clinical practice settings, with typical patients and by qualified clinicians, who may not, however, have a research background. Often, the positive results from explanatory trials have been found to be less effective in practice than they were in the lab, because several factors not present in the controlled setting can affect the eventual outcomes.
What makes pragmatic trials different?
With older people, for example, it's often difficult to recruit the required number of participants who fit strict eligibility requirements. Many older people have, or are at risk for, conditions such as high blood pressure or heart disease. These conditions are likely to exclude them from explanatory trials. In pragmatic trials, though, researchers often relax eligibility requirements and accept participants with these conditions and control for it in their analysis.
Another feature of pragmatic trials is how participants are randomized to treatment and control groups. In an explanatory trial, participants may be randomized in the order that they are recruited. In pragmatic trials, participants are often randomized at the group level. One group of participants treated in a setting such as a hospital, nursing home, clinic, or physician's practice, might receive the intervention, while people matched to be treated in a similar setting might serve as the control group. Using multiple health systems as the trial setting increases the likelihood that the results of the research can be widely applied.
Popularity is increasing
Pragmatic trials are becoming increasingly popular because they're well suited for studies of how to get health services out into wider practice. In addition to testing a particular intervention, pragmatic trials can also illustrate the differences in how the intervention works in different health care settings, such as hospitals, clinics, or physician practices. Pragmatic trials also seem likely to allow greater participation of older adults.
As health care has become more integrated, the system itself has an increasing influence on care. Pragmatic trials are taking advantage of these settings and conducting research that is specific to the practitioners and patients involved in these complex systems. They may use the full apparatus of a health system, including an electronic health record, patient reminder systems, telephone-based care, and sometimes group visits.
NIA and pragmatic trials
NIA recently joined with other NIH Institutes to fund studies using a pragmatic clinical trial approach. One relevant RFA (RFA-RM-16-019) is using the NIH Common Fund's Health Care Systems Research Collaboratory, which currently coordinates the work of nine pragmatic trials.
NIA is particularly interested in conducting additional pragmatic trials. Some of the studies now in progress include:
- PROVEN – a cluster-randomized control trial of an advance care planning video program for nursing home patients in 359 facilities within two health care systems.
- STRIDE Study – a cluster-randomized trial to determine the effectiveness for fall prevention of an evidence-based, patient-centered, multifactorial intervention that combines elements of practice redesign; a multifactorial, individually tailored intervention; and practice guidelines offered by the CDC and other organizations.
- Shed MEDS – a randomized controlled trial to evaluate the effects of an intervention to reduce medication use among hospitalized older adults discharged to skilled nursing facilities.
- TRAIN-AD – a cluster randomized controlled trial to evaluate a multicomponent intervention to improve infection management for suspected urinary and lower respiratory tract infections among advanced dementia residents in 24 Boston area nursing homes.
The National Advisory Council on Aging recently approved a concept for a funding opportunity announcement for support of additional pragmatic clinical trials. We'd love to hear your ideas for trials with real-world settings and real-world solutions. Please contact me or comment below.