Stuart F Quan

Harvard University | Harvard · Office of Technology Development

Sleep tracking by consumers is becoming increasingly prevalent; yet, few studies have evaluated the accuracy of such devices. We sought to evaluate the accuracy of three devices (Oura Ring Gen3, Fitbit Sense 2, and Apple Watch Series 8) compared to the gold standard sleep assessment (polysomnography (PSG)). Thirty-five participants (aged 20–50 year...

Rapid eye movement sleep-related bradyarrhythmia syndrome is a rare condition marked by abnormal sinus arrest or atrioventricular conduction disturbance blocks during REM sleep unassociated with sleep disordered breathing. We present a case of a young man without a cardiovascular history exhibiting pauses of up to 9.7 seconds during polysomnography...

Despite improvement in US healthcare, racial and ethnic minorities have experienced health disparities including sleep health disparities. This review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). We searched three electronic databases (PubMed, Embase, Web of Science) from the earliest available date to S...

Study objectives: Insomnia, poor sleep quality and extremes of sleep duration are associated with COVID-19 infection. This study assessed whether these factors are related to Post-Acute Sequelae of SARS-CoV-2 infection (PASC). Methods: Cross-sectional survey of a general population of 24,803 U.S. adults to determine the association of insomnia,...

There are more than 90 recognized sleep disorders, many of which impair sleep and daytime function and adversely impact heath, well-being, and chronic disease risk. Unfortunately, many sleep disorders are undiagnosed or not managed effectively. This review describes how to identify, evaluate, and treat common sleep disorders.

Internal circadian phase assessment is increasingly acknowledged as a critical clinical tool for the diagnosis, monitoring, and treatment of circadian rhythm sleep−wake disorders and for investigating circadian timing in other medical disorders. The widespread use of in‐laboratory circadian phase assessments in routine practice has been limited, mo...

Cross-sectional studies suggest that obstructive sleep apnea (OSA) is a potential risk factor for incident COVID-19 infection, but longitudinal studies are lacking. In this study, two surveys from a large general population cohort, the COVID-19 Outbreak Public Evaluation (COPE) Initiative, undertaken 147 +/- 58 days apart were analyzed to determine...

Sleep is what we spend (or should spend) one third of our lives doing. Unfortunately, many individuals fall short of their biological need for sleep many nights of the week. The reasons for this are varied and include professional or personal obligations and social determinants, including loud noises or safety concerns in one's neighborhood. This a...

Study Objectives: Insomnia, poor sleep quality and extremes of sleep duration are associated with COVID-19 infection. This study assessed whether these factors are related to Post-Acute Sequelae of SARS-CoV-2 infection (PASC). Methods: Cross-sectional survey of a general population of 24,803 U.S. adults to determine the association of insomnia, poo...

Background: Sleep is crucial for overall health and well-being. Analyzing sleep stages and sleep fragmentation can enhance our understanding of sleep quality and help protect individuals’ sleep health. The objective of this study is to explore the development and application of a multitask deep learning model that can simultaneously detect sleep ar...

Sleep stage classification is pivotal for assessing sleep quality and diagnosing sleep disorders. While deep learning has shown promise in automating sleep stage classification, the dynamic nature of sleep research and data collection processes presents unique challenges. These include class-incremental learning, where models must adapt to newly em...

Introduction Obstructive sleep apnea (OSA) is characterized by episodes of partial or complete collapse of the upper airway. OSA has been associated with increases in QTc interval and QT variability—risk factors for ventricular arrhythmias and death. This study explores how QTc and QT Variability change with positive airway pressure therapy (PAP) i...

Introduction Effective obstructive sleep apnea (OSA) treatment can potentially reduce the risk and the public health burden of OSA. While continuous positive airway pressure (CPAP) therapy remains the gold standard for treating OSA, long-term adherence is suboptimal. Although adherence to mandibular advancement devices (MADs) is higher, long-term d...

Introduction Sleep tracking using consumer devices is increasingly prevalent in the population. Given this interest, it is essential that data produced by these monitors is reliable and accurate. In a single night study with the primary aim of validating the Oura Ring in comparison to polysomnography (PSG), participants wore Oura Rings on their rig...

Objective This study assesses whether chronotype is related to COVID-19 infection and whether there is an interaction with shift work. Methods Cross-sectional survey of 19,821 U.S. adults Results COVID-19 infection occurred in 40% of participants, 32.6% morning and 17.2% evening chronotypes. After adjusting for demographic and socioeconomic facto...

Study objectives: Obstructive sleep apnea (OSA) is a highly prevalent, yet under-diagnosed condition. Due to its adverse impact on risk for cardiopulmonary disorders, there is interest in pro-active screening of OSA in hospitalized patients. We studied the long-term outcome of such screened patients who were initiated on positive airway pressure (P...

Background: Obstructive sleep apnea (OSA) is associated with COVID-19 infection. Fewer investigations have assessed OSA as a possible risk for the development of Post-Acute Sequelae of SARS-CoV-2 infection (PASC). Research Question: In a general population, is OSA associated with increased odds of PASC-related symptoms and with an overall definitio...

Background and Objectives: To investigate (1) the prevalence of sleep disorder symptoms in caregivers of children with autism spectrum disorder (ASD) and (2) the relationships between caregiver sleep problems and their health-related quality of life and family quality of life. Materials and Methods: Descriptive cross-sectional study of caregivers (...

Introduction: The goal of this study was to evaluate the association between a polygenic risk score (PRS) for QT prolongation (QTc-PRS), QTc intervals and mortality in patients enrolled in the UK Biobank with and without sleep apnea. Methods: The QTc-PRS was calculated using allele copy number and previously reported effect estimates for each singl...

Objective: The role of sleep architecture in consolidation of memory has not been extensively investigated. In this study, the association of continuous positive airway pressure (CPAP) and sleep architecture and quality, and sleep disordered breathing on changes in memory are explored during the course of a 6 month clinical trial of CPAP or sham CP...

p>Sleep is crucial for overall health and well-being. Analyzing sleep stages and the frequency of arousal can enhance our understanding of sleep quality and help protect individuals’ sleep health. The objective of this study is to explore the development and application of multi-task deep learning model that can simultaneously detect sleep arousal...

p>Sleep plays a crucial role in our overall health and well-being. Analyzing sleep stages and the frequency of arousals can enhance our understanding of sleep quality and help protect individuals' sleep health. This study delves into the application of deep learning for the simultaneous tasks of sleep staging and sleep arousal identification using...

p>Sleep plays a crucial role in our overall health and well-being. Analyzing sleep stages and the frequency of arousals can enhance our understanding of sleep quality and help protect individuals' sleep health. This study delves into the application of deep learning for the simultaneous tasks of sleep staging and sleep arousal identification using...

Sleep-disordered breathing (obstructive and central sleep apnea) are common in patients with heart failure with reduced ejection fraction. Herein, we report a 69-year-old patient with a history of severe heart failure and refractory ventricular arrhythmia who was diagnosed with a moderate degree of obstructive and central sleep apnea with Cheyne St...

Study Objectives: To (1) investigate the prevalence of sleep disorder symptoms in caregivers of children with autism spectrum disorder (ASD) and (2) the relationships between caregiver sleep problems and their health-related quality of life and family quality of life. Methods: Descriptive cross-sectional study of caregivers (N=62) of children ages...

p>The precise measurement of sleep stages is crucial for evaluating sleep quality. Deep learning has recently been utilized for automatic sleep stage classification, demonstrating exceptional performance. Previous studies on deep learning-based sleep stage classification assumed stationary data generation environments, where samples were drawn from...

p>The precise measurement of sleep stages is crucial for evaluating sleep quality. Deep learning has recently been utilized for automatic sleep stage classification, demonstrating exceptional performance. Previous studies on deep learning-based sleep stage classification assumed stationary data generation environments, where samples were drawn from...

Objective: This study assesses whether chronotype is related to COVID-19 infection and whether there is an interaction with shift work. Methods: Cross-sectional survey of 19,821 U.S. adults Results: COVID-19 infection occurred in 40% of participants, 32.6% morning and 17.2% evening chronotypes. After adjusting for demographic and socioeconomic fact...

Introduction Shift work is increasingly common in our 24/7 society and can cause sleep disturbances and excessive sleepiness. Roughly 10-43% of shift workers are diagnosed with shift work disorder (SWD), characterized by excessive sleepiness accompanied by reduced sleep duration and/or insomnia. While more individuals work early morning shifts (shi...

Introduction Obstructive sleep apnea (OSA) is associated with prolonged ventricular repolarization at baseline that further increases during sleep when an apnea/hypopnea event occurs. Aggressive treatment of OSA with positive airway pressure therapy (PAP) may further prolong ventricular repolarization during apnea/hypopnea events particularly in pa...

Introduction Transportation workers are at risk for obstructive sleep apnea (OSA), yet OSA is commonly undiagnosed in this population. In a two-phase study, we design and evaluate a tailored, mobile health (mHealth) intervention aimed at achieving OSA awareness, including changes in OSA beliefs, among operators of large highway maintenance vehicles...

Introduction Heart failure and sleep disordered breathing are prevalent in the United States and often co-exist; diagnostic strategy and management for sleep disordered breathing may change based on the presence, absence and type of heart failure. The goal of this study was to evaluate how many additional patients would be identified with either he...

Study objectives: Philips Respironics issued a voluntary recall of positive airway pressure (PAP) devices used to treat obstructive sleep apnea in June 2021. We surveyed sleep medicine clinicians from the American Academy of Sleep Medicine membership to assess the impact of the recall on clinicians and patients. Methods: One hundred and thirty-s...

Objectives: To examine the long term impact of COVID-19 on sleep patterns and development of sleep disorders. Methods: Using the centralized Massachusetts General Brigham (MGB) Research Patient Data Registry (RPDR), SARS-CoV2 positive patients were surveyed about their sleep patterns before and after the viral infection. Information related to co-m...

Introduction: Sleep is a key component of a healthy lifestyle. The center for disease control and prevention recommends thatadults get at least seven hours of sleep each night. Inadequate sleep carries its own risks including lack of focus, mood swings,heart disease, and weight gain. According to CDC data, West Virginia is the most sleep deprived s...

Frequent cortical arousal is associated with cardiovascular dysfunction among people with sleep-disordered breathing. Changes in heart rate variability (HRV) can represent pathological conditions associated with autonomic nervous system dysfunction. Previous studies showed changes in cardiac activity due to cortical arousals. However, few studies h...

Background: Medical comorbidities increase the risk of severe acute COVID-19 illness. Although sleep problems are common after COVID-19 infection, it is unclear whether insomnia, poor sleep quality and extremely long or short sleep increase risk of developing COVID-19 infection or hospitalization. Methods: Cross-sectional survey of a diverse sam...

Study objectives: Medical comorbidities increase the risk of severe COVID-19 infection. In some studies, obstructive sleep apnea (OSA) has been identified as a comorbid condition that is associated with an increased prevalence of COVID-19 infection and hospitalization, but few have investigated this association in a general population. This study...

Objectives: Involuntary job loss is a stressful life event that can result in changes in nutritional intake. Both insomnia and obstructive sleep apnea (OSA) also are associated with alterations in dietary intake, but the extent to which this occurs in those who have experienced involuntary job loss is unclear. This study assessed nutritional intake...

Study objectives: Machine learning (ML) models have been employed in the setting of sleep disorders. This review aims to summarize the existing data about the role of ML techniques in the diagnosis, classification, and treatment of sleep related breathing disorders. Methods: A systematic search in MedLine, EMBASE, and Cochrane databases through...

We conducted this systematic review and meta-analysis to evaluate the impact of obstructive sleep apnea (OSA) on gut barrier dysfunction as represented by the following biomarkers: zonulin, lipopolysaccharide, lipopolysaccharide binding protein, intestinal fatty acid binding protein, and lactic acid. A comprehensive search of the literature was con...

The Internet is a common source of sleep information, but may be subject to commercial bias and misinformation. We compared the understandability, information quality, and presence of misinformation of popular YouTube videos on sleep to videos with credible experts. We identified the most popular YouTube videos on sleep/insomnia and 5 videos from e...

Introduction: Patients with obstructive sleep apnea (OSA) are at risk for QTc prolongation, a known risk factor for increased mortality. The pro-QTc score can help identify individuals at increased risk for mortality associated with increased QTc however, it has not been evaluated in patients with OSA. The goal of this study was to evaluate the pr...

Introduction: Obstructive sleep apnea (OSA) is a highly prevalent disorder that often is unrecognized. Recently, a novel protocol for screening hospitalized patients for OSA resulted in early initiation of positive airway pressure (PAP) therapy and early post-discharge follow-up. The protocol utilizes a combination of high-resolution pulse oximetr...

Study objectives: The American Academy of Sleep Medicine recommends scoring hypopneas in adults when there is a ≥3% oxygen desaturation Or when the event is associated with an arousal. However, there is no rule regarding the duration of the interval between the event termination and the associated arousal. The purpose of this study is to explore t...

Study objectives: Sleep deficiency can adversely affect the performance of resident physicians resulting in greater medical errors. However, the impact of sleep deficiency on surgical outcomes, particularly among attending surgeons is less clear. Methods: Sixty attending surgeons from academic and community departments of surgery or obstetrics a...

Time series probabilistic forecasting with multi-dimensional and sporadic data (known as sparse data) has potential to implement monitoring kinds of physiological indices of patients in Intensive Care Unit (ICU). In this paper, we propose Transformer-based Diffusion probabilistic model for Sparse Time series Forecasting (TDSTF), a new model to pred...

Background: Medical comorbidities increase the risk of severe COVID-19 infection. In some studies, obstructive sleep apnea (OSA) has been identified as a comorbid condition that is associated with an increased prevalence of COVID-19 infection and hospitalization, but few have investigated this association in a general population. Research Question:...

Objectives We evaluated an online Sleep Health and Wellness (SHAW) programme paired with dayzz, a personalised sleep training programme deployed via smartphone application (dayzz app) that promotes healthy sleep and treatment for sleep disorders, among employees at a large healthcare organisation. Design Open-label, randomised, parallel-group cont...

Objectives: This study assessed the associations between parent intent to have their child receive the COVID-19 vaccination, and demographic factors and various child activities, including attendance at in-person education or childcare. Methods: Persons undergoing COVID-19 testing residing in Minnesota and Los Angeles County, California with childr...

Objective: This study prospectively examined change in waist circumference (WC) as a function of daily social rhythms and sleep in the aftermath of involuntary job loss. It was hypothesized that disrupted social rhythms and fragmented/short sleep after job loss would independently predict gains in WC over 18 months and that resiliency to WC gain w...

Sleep deficiencies amongst individuals with type 1 diabetes mellitus (T1DM) have been linked with dysregulated glycemic control and greater morbidities. Sleep extension (EXT) has been identified as a viable intervention target to improve adolescent outcomes. The intervention aims to emphasize collaborative work with families to engage in behaviors...

Background: Sleep deficiency can adversely affect the performance of resident physicians resulting in greater medical errors. However, the impact of sleep deficiency on surgical outcomes, particularly among attending surgeons is less clear. Methods: Sixty attending surgeons from academic and community departments of surgery or obstetrics and gyneco...

Objectives: This study assessed the associations between parent intent to have their child receive COVID-19 vaccination, and demographic factors and various child activities including attendance at in-person education or childcare. Methods: Persons undergoing COVID-19 testing residing in Minnesota and Los Angeles County, California with children ag...

Restorative sleep is a commonly used term but a poorly defined construct. Few studies have assessed restorative sleep in nationally representative samples. We convened a panel of 7 expert physicians and researchers to evaluate and enhance available measures of restorative sleep. We then developed the revised Restorative Sleep Questionnaire (REST-Q)...

Rationale Despite increased recognition of sleep disordered breathing in hospitalized patients, studies are lacking on the impact of inpatient adherence with positive airway pressure (PAP) therapy on post-discharge adherence. Objectives To assess the predictive value of inpatient adherence to PAP therapy on post-discharge compliance and adherence....

Introduction Sleep deficiency and undiagnosed or untreated sleep disorders are pervasive among employed adults, yet are often ignored in the context of workplace health promotion. Smartphone applications (apps) are a promising, scalable approach to improving sleep among employees. We evaluated an online sleep education program followed by access to...

Introduction Positive airway pressure (PAP) therapy is the mainstay treatment for obstructive sleep apnea (OSA). Continuous PAP (CPAP) therapy has been shown to decrease QTc length in electrocardiograms in patients with OSA in small studies. The impact of higher pressures of CPAP and Bilevel PAP (BPAP) on ventricular repolarization—QTc length and Q...

Introduction Evidence suggests that patients with obstructive sleep apnea (OSA) are at risk for QTc prolongation which, is a known risk factor for arrhythmias, sudden cardiac death and all cause mortality. QTc risk scores have been implemented widely to help physicians identify patients at risk for mortality however, these risk scores have not been...

Background: Obstructive Sleep Apnea (OSA) is a common sleep-related breathing disorder that often is associated with several psychiatric conditions. Job loss is a stressful life event that can also affect mental health and socioeconomic status (SES). We investigated whether there was an association between the prevalence of OSA and several psychia...

Study Objectives The American Academy of Sleep Medicine recommends scoring hypopneas in adults when there is a ≥3% oxygen desaturation Or when the event is associated with an arousal. However, there is no rule regarding the duration of the interval between the event termination and the associated arousal. The purpose of this study is to explore the...

Background: Obstructive Sleep Apnea (OSA) is a common sleep-related breathing disorder that often is associated with several psychiatric conditions. Job loss is a stressful life event that can also affect mental health and socioeconomic status (SES). We investigated whether there was an association between the prevalence of OSA and several psychiat...

The novel corona virus that is now known as (SARS-CoV-2) has killed more than six million people worldwide. The disease presentation varies from mild respiratory symptoms to acute respiratory distress syndrome and ultimately death. Several risk factors have been shown to worsen the severity of COVID-19 outcomes (such as age, hypertension, diabetes...

Purpose This study aimed to develop a machine learning–based questionnaire (BASH-GN) to classify obstructive sleep apnea (OSA) risk by considering risk factor subtypes. Methods Participants who met study inclusion criteria were selected from the Sleep Heart Health Study Visit 1 (SHHS 1) database. Other participants from the Wisconsin Sleep Cohort...

Study objectives: The long-term effect of continuous positive airway pressure (CPAP) on 24-hour blood pressure (BP) in high-risk patients with obstructive sleep apnea (OSA) is uncertain. We aimed to determine the effect of CPAP treatment on ambulatory BP in individuals with moderate or severe OSA and cardiovascular disease (CVD) or multiple CVD ri...

Background Obstructive Sleep Apnea (OSA) is a common sleep-related breathing disorder that often is associated with several psychiatric conditions. Job loss is a stressful life event that can also affect mental health and socioeconomic status (SES). We investigated whether there was an association between the prevalence of OSA and several psychiatr...

Introduction Variability and prolongation of ventricular repolarization – measured by changes in QT interval and QT variability are independently associated with ventricular arrhythmias, sudden death, and mortality but such studies did not examine the role of sleep-disordered breathing. We aimed to determine whether sleep-disordered breathing moder...

Continuous positive airway pressure (CPAP) is currently the most effective treatment for obstructive sleep apnea (OSA) and is considered the “gold standard” for patient care. The most common indications for treatment are excessive daytime sleepiness, disruption in sleep quality, and reduction in overall quality of life. In addition, CPAP is used to...