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Association between patient-perceived and device-recorded continuous positive airway pressure usage discrepancy and sleep restfulness in patients with obstructive sleep apnea receiving continuous positive airway pressure therapy

This study demonstrates that in patients with obstructive sleep apnea, a greater positive discrepancy between subjective and objective CPAP usage duration, alongside shorter subjective sleep latency, is independently associated with higher sleep restfulness, suggesting that clinical assessments should incorporate patients' subjective perceptions of therapy use rather than relying solely on device-recorded data.

Original authors: Satoshi Hamada, Michiko Tsuchiya, Tsuguru Hatta, Fuyuko Hatta, Nobuhiro Shibata, Yasuhisa Sintani, Hisashi Ooka, Maya Tojima, Hironobu Sunadome, Kimihiko Murase, Yukio Nagasaka, Toyohiro Hirai, Susumu

Published 2026-10-23

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CC BY 4.0

Original authors: Satoshi Hamada, Michiko Tsuchiya, Tsuguru Hatta, Fuyuko Hatta, Nobuhiro Shibata, Yasuhisa Sintani, Hisashi Ooka, Maya Tojima, Hironobu Sunadome, Kimihiko Murase, Yukio Nagasaka, Toyohiro Hirai, Susumu Sato

Original paper licensed under CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). ✨ This is an AI-generated explanation of the paper below. It is not written or endorsed by the authors. For technical accuracy, refer to the original paper. Read full disclaimer

Sleep is a fragile state, easily disturbed by the simple act of breathing. For millions of people worldwide, the airway collapses repeatedly during the night, cutting off oxygen and shattering sleep into a series of brief, unconscious awakenings. This condition, known as obstructive sleep apnea, leaves sufferers exhausted, foggy-headed, and at higher risk for heart trouble. The standard treatment is a machine that gently blows air into the nose or mouth to keep the airway open, allowing the sleeper to breathe normally. While doctors can see exactly how long the machine runs, they often find that patients remember using it for a different amount of time. This gap between what the machine records and what the patient feels has long been a puzzle in sleep clinics, but until now, no one knew if that gap mattered for how rested a person actually felt.

A team of researchers in Japan recently set out to solve this puzzle by listening to nearly a thousand patients. They gathered data from people with sleep apnea who were already using the air-pressure machines. The team asked these patients to fill out questionnaires about their nights: how long it took them to fall asleep, how long they thought they used the machine, and most importantly, how rested they felt upon waking. They then compared these personal answers with the hard data downloaded directly from the machines, which recorded the exact minutes of usage. The goal was simple: to see if the difference between a patient's memory and the machine's log had any connection to their sense of sleep quality.

The study involved 906 patients who provided complete information. When the researchers looked at the numbers, they found a clear pattern. On average, patients remembered using the machine for about six minutes longer than the device actually recorded, though this difference varied widely from person to person. Some patients felt they used the machine for much longer than it did, while others felt they used it for less time than the log showed. When the team sorted the patients by how rested they felt, a distinct trend emerged. Those who reported feeling the most rested tended to have a larger gap where they believed they used the machine for more time than the device confirmed. In other words, the more a patient overestimated their usage time, the more likely they were to report a deep, restful sleep.

This finding held true even after the researchers accounted for other factors like age, body weight, and whether the patients were taking sleep medication. The analysis showed that two things independently predicted a feeling of restfulness: falling asleep quickly and having a positive gap between subjective and objective usage time. Patients who felt they used the machine for more than twenty-one minutes longer than the machine recorded were significantly more likely to feel rested. Conversely, those who felt they used it for less time than the machine showed, or who took a long time to fall asleep, were less likely to feel refreshed. The researchers noted that this does not mean patients should lie about their usage, but rather that their perception of using the therapy might be a sign that the treatment is working well for them.

The study suggests that the way a patient feels about their treatment is just as important as the raw data the machine collects. While doctors have traditionally relied on the device logs to judge if a therapy is successful, this research indicates that a patient's own sense of how long they used the machine is linked to their actual sleep quality. The authors propose that in future check-ups, clinicians should pay closer attention to how patients perceive their own therapy duration. By understanding that a patient's belief in their usage time correlates with feeling rested, doctors might be better equipped to help them achieve the restorative sleep they need. The work highlights that sleep is not just a mechanical process of air pressure and time, but a personal experience where the mind's perception plays a vital role in the body's recovery.

Technical Summary: Association Between Patient-Perceived and Device-Recorded CPAP Usage Discrepancy and Sleep Restfulness

Problem Statement
Clinical management of Obstructive Sleep Apnea (OSA) relies heavily on device-recorded (objective) Continuous Positive Airway Pressure (CPAP) usage duration to define adherence. However, a persistent discrepancy exists between the duration patients report (subjective) and the duration recorded by the device (objective). While previous research has established that objective CPAP usage correlates with sleep restfulness, it remains unclear how the discrepancy between subjective and objective usage metrics influences a patient's perceived sleep quality. This study addresses the gap in understanding whether the divergence between what patients believe they are doing and what the machine records is independently associated with sleep restfulness.

Methodology
This was a multicenter, prospective, questionnaire-based study conducted across eight medical institutions in Japan between February and December 2025.

Participants: From an initial survey of 1,043 patients with OSA receiving CPAP therapy, 906 patients were included in the final analysis after excluding those with missing data regarding clinical characteristics, questionnaire scores, or device parameters.
Data Collection:
- Objective Data: Extracted from medical records and CPAP device downloads for the 1-month period preceding the survey. This included the Apnea-Hypopnea Index (AHI), mean usage duration, leak levels, and device manufacturer details. Good adherence was defined as usage ≥4 hours/night on ≥70% of nights.
- Subjective Data: Collected via a sleep-related questionnaire including the Japanese version of the Epworth Sleepiness Scale (JESS), subjective sleep latency, subjective CPAP usage duration, and sleep restfulness.
- Primary Metric: Sleep restfulness was assessed on a 5-point Likert scale (1 = restless to 5 = restful), with a score of 5 defined as "restfulness."
- Discrepancy Calculation: Defined as Subjective CPAP Usage Duration minus Objective CPAP Usage Duration.
Statistical Analysis: Univariate analyses (Jonckheere–Terpstra test for trends, Chi-square, or Cochran–Armitage test) compared variables across sleep restfulness scores. Multivariate logistic regression was performed to identify independent factors associated with sleep restfulness, utilizing variables with $p < 0.05$ in univariate analysis.

Key Results

Demographics and Baseline: The cohort consisted of 79.7% men with a median BMI of 26.6 kg/m². The median residual AHI was 1.7 events/hour, and 69.0% of patients achieved good CPAP adherence.
Usage Discrepancy: The median discrepancy between subjective and objective usage was 6 minutes (Interquartile Range: −32 to 21), indicating that, on average, patients slightly overestimated their usage, though the range was wide.
Associations with Sleep Restfulness:
- Trend Analysis: As sleep restfulness scores increased, subjective sleep duration showed a significant increasing trend ( $P_{trend} < 0.0001$ ), while subjective sleep latency showed a significant decreasing trend ( $P_{trend} < 0.0001$ ).
- Discrepancy Trend: The discrepancy between subjective and objective usage exhibited a significant increasing trend with higher sleep restfulness scores ( $P_{trend} = 0.013$ ). Specifically, patients reporting higher restfulness tended to have a larger positive discrepancy (overestimating usage more).
- Multivariate Analysis: The study identified that the following factors were independently and positively associated with sleep restfulness (score of 5):
  - Age > 65 years.
  - Use of sleep medications.
  - Shorter subjective sleep latency (≤10 minutes).
  - JESS score < 11 (no excessive daytime sleepiness).
  - Good adherence to CPAP therapy (objective).
  - Longer subjective sleep duration (>420 minutes).
  - Greater positive discrepancy between subjective and objective CPAP usage duration (>21 minutes).

Key Contributions
The study provides novel evidence that the discrepancy between subjective and objective CPAP usage is not merely a measurement error but is independently associated with sleep restfulness. Specifically, a greater positive discrepancy (where patients perceive they used the device longer than the device recorded) correlates with higher reported sleep restfulness. This suggests that the patient's perception of their therapy adherence may be a distinct psychological or physiological marker of therapeutic satisfaction and sleep quality, separate from the raw objective data.

Significance and Claims
The authors conclude that clinical assessment of CPAP therapy should not rely exclusively on device-recorded objective data. Instead, clinicians should incorporate patients' subjective perceptions of their usage duration. The paper posits that because CPAP therapy may enhance sleep restfulness, patients might consequently overestimate their usage duration; this overestimation appears linked to a positive subjective experience (restfulness). Therefore, to optimize perceived sleep restfulness, clinical management should actively consider the patient's subjective narrative alongside objective compliance metrics.

The authors maintain a modest tone regarding causality, noting that the cross-sectional design precludes causal inference. They do not claim that manipulating the discrepancy will improve restfulness, but rather that the discrepancy is a significant, independent factor associated with the outcome. They also acknowledge limitations, including the lack of objective sleep latency confirmation (via polysomnography) and the absence of detailed data on specific sleep medication classes.

Technical Summary: Association Between Patient-Perceived and Device-Recorded CPAP Usage Discrepancy and Sleep Restfulness

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