Newer technologies make studying patients for more than one night easier than ever. What are the pros and cons of this approach?

By Yoona Ha

Sleep is complicated, and many reasons could account for irregularities in sleep patterns from one night to another. From alcohol to sleeping position, even seemingly minor changes in a person’s nighttime routine can significantly impact the results of polysomnography. 

Recently, researchers found single-night sleep studies could miss moderate and mild obstructive sleep apnea (OSA) up to 60% and 84% of the time, respectively.1 Another recent study published in CHEST, which examined 10,340 adults, found that monitoring just one night’s worth of data resulted in notable misdiagnoses in OSA severity. The study’s population was administered home sleep tests (HSTs) and found that collecting three night’s value of data “clearly provides an alternative for diagnosing sleep apnea that’s accessible for all healthcare professionals.”2

Multiple-night sleep studies are hardly a new concept but haven’t been trending among providers, patients, or payers until recently. What are the pros and cons to consider?

Patient Preferences

For sleep specialist and head and neck surgeon Jordan Stern, MD, who founded BLUESLEEP, a sleep apnea and snoring center licensed in 8 states, studies that find increased accuracy with multnight testing are far from surprising.

“While there are exceptions, doing in-lab studies for diagnosis of sleep apnea is the wrong thing to do and scares most patients away,” Stern says. “The result is that patients don’t trust sleep doctors, they don’t trust sleep labs, and they prefer to get their sleep information from their Apple Watch, Fitbit, or other wearables.”

Even before the COVID-19 pandemic made in-lab testing fraught, they posed challenges for many patients regarding time, cost, and convenience. What we should be asking, according to Stern, is: What do your patients prefer and what do they want from this experience?

Representatives of sleep diagnostics company Nox Medical also echo this perspective, adding that the demand for more data should be met with better product design.

“The key benefit of multi-night testing is to minimize the so-called ‘first-night effect’ and night-to-night variability,” says Ingvar Hjalmarsson, chief product officer at Nox Medical, noting that the company’s T3 home sleep test includes multi-night features. “The question is, how many nights is enough? The key challenges include analyzing the large amount of data collected, increased patient load with having to attach a device for many nights, storing and keeping the data, and evaluating how many nights are enough.”

Newer Technology Facilitates Multinight Testing

“The technology has improved over the years, the costs have gone down and has made it easier to sample multiple nights of sleep in the comfort of the patient’s home,” Stern says. For example, at BLUESLEEP, Stern uses Ectosense’s NightOwl to obtain 4 nights of sleep data to get baseline information from a patient without charging the patient for each additional night the test was performed. “I don’t see how somebody can look at me and argue that doing just one night of home sleep testing is better than doing multiple nights of home sleep testing.”

NightOwl works by placing the sensor on a patient’s fingertip, which then collects accelerometer and photoplethysmographic data that’s sent to the cloud using the platform’s analytical software. Each device can collect over a hundred hours of sleep data throughout several nights or even several years (if the patient wanted to re-test in a year or two). This means a single device can diagnose and then be used for followup testing, adherence monitoring, and titration if necessary.  (NightOwl offers additional nights of testing at no extra cost.)

Ciaran McCourt, CEO of Ectosense, explains, “We set out to change the paradigm away from the single-night tests into a more holistic view of a person’s sleep.

“The goal of this device goes beyond diagnosis. It’s also to engage the patient in a way that makes the whole onboarding process of sleep testing as smooth as possible.

“Our approach has flipped the model on its head by not only crossing the barriers posed by a medical device but also consumerizing this device in a way that leads to higher patient engagement, better clinical testing, and more pathways to the treatments that fit the patients’ needs.”

But making sleep apnea testing easier for patients has other facets too, some of which lean in favor of single-night testing—as gathering and analyzing only one night of data can mean shorter diagnostic turnaround times for patients.

Citing a study that found patients with severe sleep-disordered breathing are more adherent to treatment when wait times were shorter,3 representatives from Itamar Medical say the company puts product development emphasis on reducing diagnostic delays, while also offering flexibility for providers who want to conduct multi-night home sleep testing.

“We know that using reusable HSAT [home sleep apnea testing] even with a single-night study can delay the therapy process due to delayed results and longer shipment processes. In multi-night testing environments, this is a bigger problem,” says Shane Brown, president, US of Itamar Medical. “We’re considering solutions that may expedite the diagnostic process with immediate test results while also giving the flexibility to the clinicians to move forward with the second or third night testing by allowing them to view the results the following morning.

“Based on the latest market research, only around 30% of the clinics surveyed offer multi-night testing for their patients.4 This could be due to reimbursement limitations but we believe changing these dynamics will increase multi-night tests.”

Right now, many payers only reimburse for the first night and require a waiting period for a second night’s test to be eligible for reimbursement.

Hani Kayyali, president of sleep diagnostics company CleveMed, says, “We do not see the multi-night recordings to be as prevalent as standard overnight sleep study.” Reasons include repeated sensor hookups increasing difficulty for patients as well as the longer time commitment, he says. “We see multi-night sleep recordings as playing a bigger role if combined with other monitoring that can paint a clearer picture of the patient as a whole over a long period of time like repeated recordings of co-existing cardiac and respiratory disease states.”

It’s a growing market and without a doubt more systems are offering features that will support multi-night testing. But to see this trend really take off, changes in reimbursement policies need to occur for the additional tests to make financial sense for both the patient and provider.

Flexibility Is King

Asim Roy, MD, medical director of the Ohio Sleep Medicine Institute, says his practice naturally gravitated towards multiple night sleep testing to better meet patients’ needs. Choosing the right combination of technological tools and devices can be tricky, especially when patients’ needs are so diverse.

Roy, who is board-certified in sleep medicine and neurology, says there is no catch-all HST that’s designed to address every patient and clinician’s preferences. For example, some home sleep tests have headgear that some patients find disruptive during sleep; some detect central sleep apnea while others don’t; and some are pricier than others, which could cause patients to shy away from additional nights of testing.

But, overall, Roy says today’s providers are well equipped to do right by their patients. He says, “Our goal at the end of the day is treating a patient and not the number. The flexibility to collect multiple nights of data has tremendous benefits for the patient.”

Yoona Ha is a freelance writer and healthcare public relations professional.


  1. Stöberl AS, Schwarz EI, Haile SR, et al. Night-to-night variability of obstructive sleep apnea. J Sleep Res. 2017 Dec;26(6):782-8.
  2. Punjabi NM, Patil S, Crainiceanu C, Aurora RN. Variability and misclassification of sleep apnea severity based on multi-night testing. Chest. 2020 Jul;158(1):365-73. 
  3. Thornton CS, Tsai WH, Santana MJ, et al. Effects of wait times on treatment adherence and clinical outcomes in patients with severe sleep-disordered breathing: A secondary analysis of a noninferiority randomized clinical trial. JAMA Netw Open. 2020;3(4):e203088. 
  4. Itamar Medical survey of 213 sleep professionals, conducted February-March 2021 (data unpublished).

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