Home Sleep Apnea Test Virtual Care Results: What the Verily and ResMed Pilot Study Found

Overview

In January 2022, a team of researchers from Verily Life Sciences and ResMed Corporation published a study that changed what we know about how fast sleep apnea can be diagnosed. The study tested a fully virtual program that guided patients from an online screening questionnaire through home sleep testing and into treatment, all without a single in-person visit.

The results were striking. Patients received a confirmed diagnosis in a median of 19 days. Less than five percent dropped out along the way. Satisfaction scores were nearly perfect.

The study was published in JMIR Formative Research, a peer-reviewed journal focused on digital health. It was registered on ClinicalTrials.gov (NCT04599803) and conducted under Institutional Review Board oversight.

Here is what the researchers found, who they are, and why the results still matter.

The Program: Primasun Sleep Apnea Program

The platform tested in this study was originally called the Verily Sleep Apnea Program. It was later renamed the Primasun Sleep Apnea Program (PSAP) after the joint venture between Verily and ResMed was formally branded as Primasun in 2021.

Primasun was formed in 2018 as a joint venture between Verily, an Alphabet precision health company, and ResMed, a global leader in CPAP devices and connected sleep technology. The goal was to build a digital platform that could identify, diagnose, treat, and manage people with obstructive sleep apnea (OSA) entirely through virtual care.

The platform handled the entire patient journey:

• Online screening using the OSA-50, a validated four-question questionnaire
• Video telemedicine appointments with board-certified sleep physicians
• Home sleep apnea test (HSAT) shipped directly to the patient's home
• Follow-up video appointment to review results and plan treatment
• App-based therapy onboarding with educational content and coaching support
• 90 days of positive airway pressure (PAP) therapy monitoring

Every step was virtual. No sleep lab visit. No in-person clinic appointment. No equipment pickup or dropoff.

Study Design

This was a prospective, single-arm, multistate feasibility pilot study. Researchers recruited participants online from North Carolina and Texas between June and October 2020.

To be eligible, participants had to be 18 or older, speak and read English, own a compatible smartphone, have access to a computer with a camera, and score 5 or higher on the OSA-50 screening questionnaire, indicating high risk for sleep apnea.

People who had already been diagnosed with OSA or certain other chronic sleep disorders were excluded. Shift workers and pregnant individuals were also excluded.

The home sleep test device used was the WatchPAT ONE, a disposable wrist-worn device manufactured by Itamar Medical (now a Zoll Medical subsidiary). Participants wore the device for one night, then the data was transmitted for physician interpretation.

The study was conducted entirely on the Verily Clinical Studies Platform (originally called the Baseline Platform), which handled recruitment, consent, screening, enrollment, data collection, and study monitoring.

Who Participated

A total of 728 people completed the online screening questionnaire. Of those, 397 (55%) were eligible based on their OSA-50 scores and other criteria. A total of 187 provided informed consent, and 158 completed their first telemedicine appointment with a sleep physician.

The study population skewed female (60%), White (89%), and from Texas (65%). The average age was 47 years. Average BMI was 34.6, placing the majority in the obese category. About half had an Epworth Sleepiness Scale score above 10, indicating excessive daytime sleepiness.

The most common comorbidities were allergies (46%), high blood pressure (38%), and diabetes (19%). Three-quarters had health insurance. Two-thirds had a primary care physician. The vast majority (92%) said they were at least somewhat familiar with sleep apnea before joining the study.

Only 6% had ever completed a sleep study before. These were not patients referred by a doctor. They were people who responded to an online advertisement and decided to find out whether they had a problem.

The Results: Journey Time

The speed of the diagnostic pathway was the headline finding.

For the 157 participants ordered a home sleep test, the median time from first physician visit to receiving the HSAT device was 7.1 days. From receiving the device to getting a confirmed OSA diagnosis at the follow-up appointment, the median was 11.7 days. The total time from first physician visit to diagnosis was a median of 18.8 days.

For those diagnosed with OSA and prescribed PAP therapy, the median time from diagnosis to starting therapy was 6.0 days.

The total journey from first landing on the screening website to active PAP therapy was approximately six weeks.

These numbers are dramatically faster than standard care. Published estimates for the traditional pathway in the United States range from four weeks to over a year just for diagnosis. Veterans Health Administration facilities report an average of eight to nine months from initial referral to sleep evaluation. A Canadian study found standard care wait times averaging 152 days. In the United Kingdom, the average from physician referral to PAP initiation is approximately 14 months.

The Results: Completion Rates

The second major finding was how few patients dropped out.

Of participants who scheduled a first appointment, 86% completed it. Traditional sleep clinic studies report no-show rates between 21% and 30%.

Of those who received a home sleep test, 98% completed it successfully. Of those who completed the test, 98% returned for their follow-up results appointment.

Out of 151 participants who completed the follow-up visit, 114 were diagnosed with OSA (76%). Of those, 105 were prescribed PAP therapy. Every single one of the 105 received their device. Only two withdrew consent during the 90-day therapy period.

The total diagnostic pathway attrition after the first completed appointment was less than five percent.

The Results: Patient Satisfaction

Satisfaction with the diagnostic portion of the program averaged 4.75 out of 5.0. Eighty-four percent of respondents gave it a perfect 5 out of 5 score. Only 2% rated below a 3.

Participants rated the registration process 4.78 out of 5.0 for ease of use. Onboarding satisfaction averaged 4.69 out of 5.0.

After 90 days of PAP therapy, overall program satisfaction averaged 4.3 out of 5.0. Over 81% rated the experience as satisfied or very satisfied.

Study Limitations

The researchers were transparent about the study's limitations.

There was no control group. Without a direct comparison to standard-of-care patients, the journey time improvements cannot be attributed with certainty to the platform alone.

The study population was predominantly female, White, and from two states. Most participants had health insurance and a primary care physician. The results may not generalize to other populations.

Participants were recruited digitally, which means they were comfortable with technology. This may not represent the full undiagnosed OSA population.

Satisfaction surveys were only completed by participants diagnosed with OSA or those who continued to the PAP therapy phase. The experience of participants who were not diagnosed or who were recommended non-PAP treatments was not captured.

The study was conducted during the COVID-19 pandemic, which introduced variables including shipping delays, competing health priorities, and the Texas power outages of February 2021.

Why These Results Still Matter

The Primasun joint venture between Verily and ResMed is no longer active. The entity was absorbed back into ResMed in approximately 2024. The primasun.com website is no longer online.

But the clinical data stands on its own. This study demonstrated three findings that are relevant to anyone working on sleep apnea care:

First, virtual care can compress the diagnostic timeline from months to weeks. The technology exists. Patients will use it. The bottleneck in sleep apnea diagnosis is not patient willingness. It is pathway design.

Second, home sleep testing completion rates approach 100% when the test is shipped to the patient's home and embedded in a coordinated care pathway. The device is not the barrier. The logistics around the device are the barrier.

Third, patients stay engaged when the experience is designed around them. Low attrition, high satisfaction, and high completion rates all point to the same conclusion: patients want help with sleep apnea. They abandon the traditional pathway because the traditional pathway abandons them.

The study is freely available as an open-access publication in JMIR Formative Research.

About the Researchers

Shannon S. Sullivan, MD

Dr. Sullivan is a Clinical Professor of Pediatrics in the Division of Pulmonary, Asthma, and Sleep Medicine at Stanford University School of Medicine. She is board-certified in both Sleep Medicine and Pediatrics. She graduated from the University of Michigan Medical School in 2001 and completed her training at Stanford.

Dr. Sullivan is an active voice in sleep medicine policy through the American Academy of Sleep Medicine, contributing to position statements on topics ranging from daylight saving time to melatonin use in children. She was affiliated with Verily Life Sciences during the Primasun pilot study and continues to collaborate with Verily on sleep wearable validation research. She co-authored studies validating both the Verily Study Watch and the Verily Numetric Watch for sleep measurement, published in Frontiers in Sleep (2024) and the Journal of Sleep Research (2025).

Adam V. Benjafield, PhD

Dr. Benjafield is Vice President of Clinical Research at ResMed Corporation in San Diego. He led the landmark 2019 study published in The Lancet Respiratory Medicine that estimated 936 million people worldwide have obstructive sleep apnea. That finding, nearly ten times higher than previous estimates, reshaped how the medical community understands the scale of the OSA epidemic.

His research program at ResMed spans prevalence modeling, treatment adherence, health economics, and real-world outcomes. He has presented research on CPAP therapy outcomes, insomnia prevalence, and the intersection of depression and OSA at major conferences including SLEEP 2024. He continues to lead epidemiological modeling work, including a 2025 study projecting OSA burden in the United States through 2050.

Shefali Kumar, MPH

Kumar served as the corresponding author on this study and worked as a Health Economics Manager at Verily Life Sciences in South San Francisco. She led the design and execution of the Primasun pilot and co-authored the follow-up study on PAP usage and program engagement, published in Frontiers in Sleep in 2023.

Cynthia Dorsey, PhD, cBSM

Dr. Dorsey is a sleep scientist who holds certification in Behavioral Sleep Medicine (cBSM) from the American Academy of Sleep Medicine. She was affiliated with Verily Life Sciences and served as a consultant on the Primasun sleep program development. She co-authored both the patient journey metrics study and the follow-up PAP adherence study.

Emma Rudie, MSc

Rudie was a researcher at Verily Life Sciences and co-authored both Primasun pilot studies. She contributed to study design, data analysis, and manuscript development for the patient journey metrics and PAP usage publications.

Amy Blase, BS

Blase was a researcher at ResMed Corporation in San Diego and represented ResMed's contribution to the joint venture research. She co-authored both the initial patient journey study and the follow-up PAP adherence publication.