Using ingestible sensors to improve medication adherence

Wearable technology is popular within the healthcare system as it expands clinicians' ability to gather patient health information, track health metrics over time, and tweak treatment plans. These technologies are typically worn on the body, enabling remote patient monitoring. Researchers have developed wearable sensors that can detect COVID-19, as well as ones that can help predict heart attacks.

However, healthcare researchers are now wondering: What if they could also work from inside the body?

Mass General Brigham is looking into this, with researchers investigating whether ingestible sensors can ease the long-standing challenge of medication adherence.

Medication adherence refers to patients taking their medications as directed. Poor medication adherence could result from patients not filling prescriptions, skipping doses or cutting doses in half. Medication adherence is one of the most intractable hurdles to improving patient care, particularly in chronic disease management. A February 2023 study showed that around one in five adults with diabetes did not maintain the use of glucose-lowering medications between 2005 and 2018.

Psychiatric care is another area where medication adherence is critical and difficult to achieve. Thus, Mass General Brigham researchers are exploring whether ingestible sensors can enhance medication adherence in psychiatric care -- and their potential appears highly promising.

What are the challenges to ensuring medication adherence?

According to Peter Ray Chai, MD, an emergency medicine physician and associate professor of emergency medicine at Mass General Brigham, the factors driving medication adherence are varied, ranging from psychosocial issues to access barriers to economic hurdles.

One significant factor is patients not understanding the importance of taking their medication as directed.

"A class example is hypertension," said Chai. "You don't feel your blood pressure going up. And so, a lot of people think, why do I need to take my blood pressure medication every day?"

Medication access is another critical barrier to medication adherence. Chai noted that patients can lack access to medication for several reasons, including being uninsured or underinsured and, thus, not being able to afford the medication. Transportation can also drive access barriers, as people without a car or access to public transportation might be unable to pick up their medication.

Then, there is the psychosocial aspect. Chai explained that for some people, taking medication might remind them that they have a disease.

"So, taking your medication for depression reminds you that you have depression," he said. "That can be very stigmatizing for some people, and it can kind of help them ruminate on diseases that they have, and people might not want to feel that way and [may] stop taking their medications from that perspective."

Additionally, there are significant challenges associated with medication side effects. Chai noted that these side effects, which include weight gain, insomnia, and nausea, could result in patients avoiding the medications.

Medication adherence is vital across treatment plans; however, the success of psychiatric treatments is primarily dependent on patients taking the proper medication at the right time, as the disease and its treatment are often not physically apparent. This means there are few objective ways to ensure psychiatric care is effective.

"You think about somebody who has depression, who has worsening depression -- is something happening? Are they not taking their medications? Are they on the wrong medication? Does this dose need to change?" Chai said. "For many, many years, this has been kind of an unknown, where it's a give-and-take process between the patient and clinician."

Where do medication adherence strategies fall short?

Healthcare providers have employed numerous strategies to improve medication adherence, but hurdles to their success persist.

For instance, common direct methods involve clinicians watching patients take their medication or measuring the concentration of the medication in the patient's body, Chai said. However, these methods could be viewed as intrusive and require the patient to be physically present in a clinic, which is not always possible.

It's almost like your Apple Watch fitness data. You could see the number of pills that you took, and when you took them, where you were, all this kind of information. So, you get a very rich context-based pattern of adherence.

There are also indirect medication adherence approaches, such as measuring the medication possession ratio and the proportion of days covered, Chai noted. These pharmacy-based measures involve assessing the number of refills that somebody picks up and the amount of time a patient has the medication available.

Still, there is an inherent risk of error in using these measures, Chai explained. People could pick up their prescriptions early or late due to travel or take the medications home and still not take them as directed.

Digital medication adherence tools, like smart medication dispensers and smart inhalers, aim to overcome these issues by gathering information on how often pill bottles are opened or inhalers are used, but even so, it is not certain that the patient actually took the medication,

This underscores one of the most challenging aspects of medication adherence: every person is different, and every disease is different, Chai said.

Thus, healthcare researchers are looking to ingestible sensors to enable clinicians to tailor medication adherence approaches to individual patients.

How can ingestible sensors help improve medication adherence?

While the concept of ingestible sensors is not new -- researchers have previously used these devices to monitor patient vital signs and enhance HIV care -- Chai is working with a health technology company to apply it to medication adherence in psychiatry.

The sensors are in the form of pills integrated with a radiofrequency transmitter that emits a signal detectable by a device outside the body. He explained that the patient's medication is placed inside this pill. The outer layer dissolves in the stomach, allowing stomach acid to power the radiofrequency transmitter.

"[The sensor] confirms the fact that that pill went in someone's mouth and is in their stomach, and then the reader basically relays that data to a smartphone or a web interface," Chai said. "And so, clinicians and patients can essentially review that data together. It's almost like your Apple Watch fitness data. You could see the number of pills that you took, and when you took them, where you were, all this kind of information. So, you get a very rich context-based pattern of adherence."

The most significant benefit the sensor offers clinicians is the ability to use the information on adherence patterns to individualize strategies to improve medication adherence.

According to Chai, many behavioral strategies can prompt people to take their medications correctly. However, their efficacy is limited because they're typically taught in an office with little to no context of the person's daily life. With the data from the sensor, clinicians can create medication adherence approaches that better fit a person's lifestyle. Further, they can automate conversations and reminders on medication directives.

For instance, if a patient forgets to take their medications on weekends or certain weekdays, clinical teams can create automated reminders that are sent to them on those days, Chai explained.

The technology offers exciting possibilities for solving medication adherence issues. Though there is still work to be done, particularly in developing clinical workflows and reimbursement pathways to bring the devices into real-world clinical settings, the technology itself is ready.

"The technology can always get better, but I think we're at a place where we have a lot of real-world experience in a research setting with patients -- we send patients home with these things all the time, and we get good data," Chai said. "And so, I think, it's not for everybody, but for the right person or the right disease, I think the technology is mature enough that it could be in the hands of people today."

Anuja Vaidya has covered the healthcare industry since 2012. She currently covers the virtual healthcare landscape, including telehealth, remote patient monitoring and digital therapeutics.