Better ways sought to gauge patients’ experiences in PAH trials

Outcomes of clinical trials don't always reflect priorities of patients or clinicians

Marisa Wexler, MS avatar

by Marisa Wexler, MS |

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A doctor listens to a patient who is making a point.

The outcomes used in clinical trials of pulmonary arterial hypertension (PAH) don’t fully reflect the priorities of patients and clinicians, a new study asserts.

The study, “‘It’s that invisible illness’: Patient and clinician perspectives on outcomes in pulmonary arterial hypertension treatment,” was published in the journal Pulmonary Circulation.

Clinical trials are rigorously designed scientific studies with human participants that are the gold standard for testing potential treatments for diseases like PAH. A critical part of designing clinical trials is finding the right endpoints — that is, assessing if the treatment is effective.

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In PAH, trials commonly use endpoints like objective measures of the pressure in the lung’s blood vessels, or the distance a patient can walk in six minutes, known as the 6MWD, as a measure of physical function.

A team of U.S. scientists wanted to better understand the priorities of people with PAH and clinicians who treat the disease, with an eye toward  comparing whether patients’ priorities lined up with common trial endpoints. To learn more, the team conducted interviews with 11 people living with PAH and eight PAH clinicians.

Patients viewed the impact of PAH through the lens of how it interfered with day-to-day activities and caused complicated feelings in interactions with other people.

“It’s that invisible illness that people can’t physically see what’s going on, so they think that you’re exaggerating your symptoms and what you’re going through,” one patient said.

“Just not being able to do normal things that I have to do every day,” another said. “I’m always in pain or tired. And I try not to take advantage of people. It makes me feel guilty that they have to do more than I do.”

Also, patients generally expressed desires for treatments that could help them better function on their own in daily life, like being able to run errands without having to stop to rest.

The clinicians’ perspective

Whereas patients tended to view their disease based on their day-to-day experiences, clinicians generally placed more emphasis on objective clinical outcomes. For example, one clinician said that “the ideal [outcome] would be a low-risk status based off our risk calculations.”

While these objective measures were viewed as important from a clinical perspective, the clinicians acknowledged they don’t always capture the patient experience.

“Frequently, I will see improvements on the physician’s side of it. But, in reality, they [the patients] don’t feel any better,” one clinician said. “All these objective tests we do are what the physician wants to see. The quality of life is what the patient wants to see.”

While some standardized tests have been created to evaluate quality of life for people with PAH, there’s not yet a consensus on which test best captures patients’ experiences. Better standardizing these measures was seen as an important need.

“We’re not very good at applying [standardized measures of quality of life], but I think those are really, really important…It’s just that we haven’t had a chance to implement it,” one of the doctors said. “As a physician, I feel like I’m pretty quick to know if they’re happy or not, or if they feel like their quality of life is good. But I think that that’s something that we haven’t done – establish a standardized matrix.”

‘Definition of functional’ differs

Part of the problem with trying to standardize a measure of life quality for PAH is that “everybody’s definition of functional is different,” another clinician said.

“There are some really individual differences and it varies by demographic and type of patient,” a clinician said. “For younger people, functional means being able to work and take care of their family or go to school. Older people being able to enjoy a more peaceful less taxing life and retirement.”

Overall, the researchers concluded, “patients and clinicians identified distinct outcomes to assess PAH treatment response, few of which are measured in PAH clinical trials.”

Some clinicians have begun exploring using wearable sensors (such as Fitbit) to track patients’ activity in day-to-day life as an objective way to measure changes in physical activity. The researchers highlighted a need for further research to validate these methods and determine how they might be used in clinical studies.

The scientists noted that this study was a small investigation meant to serve as a springboard for further research, so the results should be interpreted in that context. Of note, nearly all of the participants in this study were white, and all of the clinicians worked at specialty centers.

As such, the researchers said, “these perspectives may not sufficiently represent those of caregivers, PAH patients from racial and ethnic minorities, historically disadvantaged populations, or nonacademic PAH clinics,” highlighting a need for more research to spotlight more diverse perspectives.

A Conversation With Rare Disease Advocates