Science of Patient Input (SPI)

Part 2: Patient input into study design – endpoints of value and thresholds of “significance”

Last time we discussed how patients’ opinions can shape the design of a clinical study by altering the important endpoints and perceived risk of a medical procedure.  See part one of Science of Patient Input here. Since medical device companies develop products to fulfill unmet needs or to improve outcomes delivered by existing products it is relevant to consider who should determine what unmet needs are priorities, or which medical outcomes should be targeted. It is reasonable that patients’ opinions be heard on these matters.  The healthcare industry is built on serving patients, but the details about the specific health conditions, prognoses, treatment availability, cost, and patients’ social cultures all factor in their preferences.  So when designing and evaluating medical devices, what better guide to use than patients themselves?

When designing a clinical trial to evaluate a medical device, there are scientific and regulatory requirements that must be met (trial sample size, randomization scheme, safety measures, etc.).  But there may be discretion in the measures that are used to evaluate device effectiveness.  For example, device trials tend to focus on objective measurements of device performance (e.g., percent stenosis of a blood vessel following deployment of an arterial stent).  However, the patients receiving those permanent implant devices may care more about subjective measures like return to function or reduction in claudication, which can be measured by a mobility exam or a pain evaluation.  The most efficient endpoints can potentially act as objective measures of success while also speaking to patient quality of life, such as the need for reintervention following a device implant.  The success of a device should be predicated on its ability to improve patients’ lives rather than solely on a lab value that may or may not translate to clinically meaningful improvement.

The definition of “clinically meaningful improvement” is another area in which patient input can prove invaluable.  Depending on the quality of life associated with a patient’s medical condition (especially if debilitating), he or she might be willing to accept a higher level of risk to obtain reasonable improvement in quality of life without a “significant” objectively measured improvement in the underlying condition.  If a study of patient preferences reveals that this is true for the majority of a certain patient population, the threshold for trial success can be set accordingly, and regulators may consider the device risks to be outweighed by a relatively reduced improvement of the underlying condition. This could ultimately get important new devices to market and helping patients sooner.

A recently completed clinical device trial illustrates the impact this kind of patient feedback could have had.  The experimental device was meant to help reconstruct the patient’s nipple following mastectomy.  Due to the nature of the device materials, the manufacturer considered it successful if the device retained half of the nipple projection length over time.  The trial missed this goal by a small margin, causing it to fail its primary endpoint statistically.  However, the trial also happened to collect a patient satisfaction survey, and the survey showed that the patients were very satisfied with their results.  If not for that additional information, the product could have been abandoned after statistical failure of its primary clinical trial endpoint.  If patients had been given input to the clinical trial design process, the trial endpoints could have been chosen to better reflect the ultimate goals of the patients and of this device.

Please check back for additional posts describing the potential uses of patient preference information to design more efficient clinical trials that are more likely to be successful and thus could save companies significant time and resources.

If you have any questions about how to design more efficient, cost-effective clinical trials, please call us at 855.463.1633 or visit our website


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