Awareness Level of Obstructive Sleep Apnea Syndrome During Routine Unstructured Interviews of a Standardized Patient by Primary Care Physicians

Impact of comorbid sleep-disordered breathing on escitalopram treatment in patients newly diagnosed with generalized anxiety disorder: A 12-week prospective observational study

We aimed to evaluate the presence of sleep-disordered breathing (SDB) in generalized anxiety disorder (GAD) patients and its impacts after 12-week of escitalopram treatment. In this prospective observational study, GAD patients were followed up to determine whether comorbid SDB affects their treatment response. They underwent a home sleep apnea test (HSAT), and oxygen desaturation index ≥5 was considered indicative of SDB. All participants were treated with escitalopram 5 mg in the first 2 weeks and 10 mg in the remaining 10 weeks. They underwent assessments of heart rate variability and completed questionnaires for sleep, mood, attention, and daytime sleepiness on the day of enrollment, and 2 weeks, 4 weeks, and 12 weeks later. A total of 45 GAD participants (mean age, 56.2 years) were included in the study. Of these, 53.3% had comorbid SDB. Participants with GAD and SDB had higher baseline Beck Anxiety Inventory (BAI) and STOP-BANG scores. Both groups of participants with GAD showed overall improvement in anxiety, depression, and insomnia symptoms after 12 weeks of escitalopram treatment. Additionally, there were no statistically significant differences in the changes in BAI, Beck Depression Inventory, and Epworth Sleepiness Scale scores between the two groups at the Week 2, Week 4, and Week 12 assessments compared to baseline. However, the GAD group with comorbid SDB seemed to have a lower tendency for improvement in depressive symptoms than the group with non-comorbid SDB. Compared with the GAD group without comorbid SDB, the GAD group with comorbid SDB exhibited more severe anxiety symptoms at baseline and tended to show less improvement in depressive symptoms after 12 weeks of escitalopram treatment.

FOUND Trial: randomised controlled trial study protocol for case finding of obstructive sleep apnoea in primary care using a novel device

INTRODUCTION

Obstructive sleep apnoea (OSA) is a common, but underdiagnosed, sleep disorder. If untreated, it leads to poor health outcomes, including Alzheimer's disease, cancer, cardiovascular disease and all-cause mortality. Our aim is to determine the feasibility and cost-effectiveness of moving the testing for OSA into general practice and how general practitioner (GP)-based screening affects overall detection rates.

METHODS AND ANALYSIS

Randomised controlled trial of case finding of OSA in general practice using a novel Medicines and Healthcare products Regulatory Agency-registered device (AcuPebble SA100) compared with usual care with internal feasibility phase. A diverse sample of general practices (approximately 40) from across the West Midlands Clinical Research Network will identify participants from their records. Eligible participants will be aged 50-70 years with body mass index >30 kg/m2 and diabetes (type 1 or 2) and/or hypertension (office blood pressure >145/90 mm Hg or on treatment). They will exclude individuals with known OSA or chronic obstructive pulmonary disease, or those they deem unable to take part. After eligibility screening, consent and baseline assessment, participants will be randomised to either the intervention or control group. Participants in the intervention arm will receive by post the AcuPebble sleep test kit. Those in the control arm will continue with usual care. Follow-up questionnaires will be completed at 6 months. The study is powered (90%) to detect a 5% difference and will require 606 patients in each arm (713 will be recruited to each arm to allow for attrition). Due to the nature of the intervention, participants and GPs will not be blinded to the allocation.

OUTCOMES

Primary: Detection rate of moderate-to-severe OSA in the intervention group versus control group. Secondary: Time to diagnosis and time to treatment for intervention versus control group for mild, moderate and severe OSA; cost-effectiveness analysis comparing the different testing pathways.

ETHICS AND DISSEMINATION

The trial started on 1 November 2022. Ethical approval was granted from the South Central Oxford A Research Ethics Committee on 9 June 2023 (23/SC/0188) (protocol amendment version 1.3; update with amendment and approval to renumber to V2.0 on 29 August 2023). Patient recruitment began on 7 January 2024; initial planned end date will be on 31 April 2025.Results will be uploaded to the ISRCTN register within 12 months of the end of the trial date, presented at conferences, submitted to peer-reviewed journals and distributed via our patient and public involvement networks.The University of Warwick will act as the trial sponsor. The trial will be conducted in accordance with the Sponsor and Primary Care Clinical Trials Unit standard operating procedures.

TRIAL REGISTRATION NUMBER

ISRCTN 16982033.

From Snoring to Soaring: Unveiling the Positive Effects of Continuous Positive Airway Pressure Ventilation on Cardiovascular Health in Patients With Obstructive Sleep Apnoea Through a Systematic Review

Increased cardiovascular (CV) morbidity and death are linked to obstructive sleep apnoea (OSA). The primary method of treating OSA is continuous positive airway pressure (CPAP). CPAP has some debatable outcomes on CV events in people suffering from OSA. The current study investigates how CPAP affects CV outcomes. The goal is to evaluate CPAP's effectiveness in lowering CV outcomes in OSA patients. We used a computer to search the PubMed, PubMed Central Library, Science Direct, and Google Scholar databases for studies comparing the effects of CPAP and a control group on CV outcomes in OSA patients. These included randomised control trials (RCT), narrative reviews, systematic reviews, case-control studies, observational studies and meta-analyses. A total of 52,937 patients were included in the final analysis of six RCTs, four observational studies, 10 meta-analyses, one case-control study, two systematic reviews and one narrative review. The weighted mean follow-up lasted for a period of between three months and nine years. The risk of major cardiovascular adverse events (MACE) was the same for both the CPAP and control groups. According to subgroup analysis, patients with lower MACE adherence rates (four hours per night) were more likely to use CPAP. The risk of all-cause mortality, CV-related complications causing mortality, acute myocardial infarction acute stroke, or hospitalisations for angina was the same in the CPAP and control groups. The primary outcome was that in patients with therapy with CPAP in addition to usual care and usual care alone did not prevent CV events in patients with moderate-to-severe OSA and existing CV illness. Patients with OSA who utilise CPAP may not experience fewer CV events. Patients who use CPAP consistently (four hours per night) could benefit from improved CV results. Future research must assess how well-adherent patients with severe OSA and low CV event rates respond to CPAP therapy. In patients who use CPAP for more than four hours each night, CPAP therapy may minimise the risk of MACE and stroke. Additional randomised trials requiring adequate CPAP time adherence are needed to support this perception. Despite the fact that there is no evidence to support the claim that CPAP therapy improves CV outcomes, bias difficulties, CPAP adherence problems, and the patient groups included in each RCT may have made it more difficult to generalise the findings to all patients. Future research is therefore needed to look at these relevant results.

Multi-stage sleep classification using photoplethysmographic sensor

The conventional approach to monitoring sleep stages requires placing multiple sensors on patients, which is inconvenient for long-term monitoring and requires expert support. We propose a single-sensor photoplethysmographic (PPG)-based automated multi-stage sleep classification. This experimental study recorded the PPG during the entire night's sleep of 10 patients. Data analysis was performed to obtain 79 features from the recordings, which were then classified according to sleep stages. The classification results using support vector machine (SVM) with the polynomial kernel yielded an overall accuracy of 84.66%, 79.62% and 72.23% for two-, three- and four-stage sleep classification. These results show that it is possible to conduct sleep stage monitoring using only PPG. These findings open the opportunities for PPG-based wearable solutions for home-based automated sleep monitoring.

Age and sex differences on the association between anxiety disorders and obstructive sleep apnea: A nationwide case-control study in Taiwan

AIM

The aim of this study was to examine the association between anxiety disorders and obstructive sleep apnea (OSA).

METHODS

This is a population-based, retrospective case-control study using Taiwan's nationwide database. We included patients with OSA aged ≥12 years, diagnosed according to the International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) codes: 327 and 780. Each enrolled patient with OSA needed to undergo a polysomnography examination within 1 year pre- or post-OSA occurrence. Patients with OSA and controls were selected in a 1:4 ratio. Patients with anxiety disorders (ICD-9-CM code 300) were diagnosed by board-certified psychiatrists and required to visit the outpatient clinic at least three times per year. Multivariate logistic regression and interaction analyses were used to evaluate the objective association.

RESULTS

This study enrolled 7987 and 31 948 participants with and without OSA, respectively. A significant difference in anxiety exposure was observed only pre-OSA diagnosis but not post-OSA diagnosis. Compared with patients without anxiety disorders: (i) those with anxiety disorders had an adjusted odds ratio (aOR) of ≈1.864 in OSA comorbidity (aOR = 1.864; 95% confidence interval [CI] = 1.337-2.405); and (ii) subgroup analysis showed a significant interaction that anxiety patients of male sex, aged 18 to 44 years, aged 45 to 64 years, and hypertension had a higher aOR in OSA comorbidity (aOR = 2.104 [95% CI = 1.436-2.589], aOR = 1.942 [95% CI = 1.390-2.503], aOR = 2.179 [95% CI = 1.564-2.811], and aOR = 2.092 [95% CI = 1.497-2.706], respectively).

CONCLUSION

The study revealed a higher ratio of previous anxiety exposure in patients with OSA. Compared with those without anxiety, anxiety patients of male sex, aged 18 to 64 years, and with hypertension had a higher risk of OSA comorbidity.

In-office communication about excessive daytime sleepiness associated with treated obstructive sleep apnea: insights from an ethnographic study of physician-patient visits

Background

Excessive daytime sleepiness (EDS), a primary symptom of obstructive sleep apnea (OSA), negatively affects functioning and quality of life (QoL). EDS can persist despite primary airway therapy, and often remains unmanaged, potentially due to inadequate provider-patient communication. Ethnographic research was conducted to assess provider-patient communication about EDS.

Methods

Participating physicians (primary care n = 5; pulmonologists n = 5; sleep specialists n = 3) identified adult patients (n = 33) diagnosed with OSA who were prescribed positive airway pressure (PAP) therapy ≥6 months prior and previously reported EDS. Visits and post-visit interviews were video-recorded and analyzed using standardized, validated sociolinguistic techniques.

Results

Despite 55% of patients (18/33) reporting QoL impacts post-visit, this was discussed during 28% (5/18) of visits. Epworth Sleepiness Scale was administered during 27% (9/33) of visits. Many patients (58% [19/33]) attributed EDS to factors other than OSA. Physicians provided EDS education during 24% of visits (8/33). Prior to the visit, 30% (10/33) of patients were prescribed EDS medication, of which 70% (7/10) reported currently experiencing EDS symptoms.

Conclusions

EDS was minimally discussed and rarely reassessed or treated after PAP therapy initiation in this study. Patients often attributed EDS to factors other than OSA. The findings suggest physicians and patients may benefit from dialogue tools, routine use of screening tools, and patient education.

The invisible costs of obstructive sleep apnea (OSA): Systematic review and cost-of-illness analysis

BACKGROUND

Obstructive sleep apnea (OSA) is a risk factor for several diseases and is correlated with other non-medical consequences that increase the disease's clinical and economic burden. However, OSA's impact is highly underestimated, also due to substantial diagnosis gaps.

OBJECTIVE

This study aims at assessing the economic burden of OSA in the adult population in Italy by performing a cost-of-illness analysis with a societal perspective. In particular, we aimed at estimating the magnitude of the burden caused by conditions for which OSA is a proven risk factor.

METHODS

A systematic literature review on systematic reviews and meta-analyses, integrated by expert opinion, was performed to identify all clinical and non-clinical conditions significantly influenced by OSA. Using the Population Attributable Fraction methodology, a portion of their prevalence and costs was attributed to OSA. The total economic burden of OSA for the society was estimated by summing the costs of each condition influenced by the disease, the costs due to OSA's diagnosis and treatment and the economic value of quality of life lost due to OSA's undertreatment.

RESULTS

Twenty-six clinical (e.g., diabetes) and non-clinical (e.g., car accidents) conditions were found to be significantly influenced by OSA, contributing to an economic burden ranging from €10.7 to €32.0 billion/year in Italy. The cost of impaired quality of life due to OSA undertreatment is between €2.8 and €9.0 billion/year. These costs are substantially higher than those currently borne to diagnose and treat OSA (€234 million/year).

CONCLUSIONS

This study demonstrates that the economic burden due to OSA is substantial, also due to low diagnosis and treatment rates. Providing reliable estimates of the economic impact of OSA at a societal level may increase awareness of the disease burden and help to guide evidence-based policies and prioritisation for healthcare, ultimately ensuring appropriate diagnostic and therapeutic pathways for patients.

Bone mineral density alteration in obstructive sleep apnea by derived computed tomography screening

The association between obstructive sleep apnea (OSA) and bone mineral density (BMD) is poorly elucidated and has contradictory findings. Abdominal computed tomography (CT) for other indications can provide a valuable opportunity for osteoporosis screening. Thus, we retrospectively explored the association between OSA and BMD by examining abdominal CT vertebrae images for a multitude of conditions and indications. We included 315 subjects (174 with OSA and 141 without OSA) who performed at least two CT scans (under similar settings). Both groups had a similar duration between the first and second CT scans of 3.6 years. BMD decreased in those with OSA and increased age. A multivariate linear regression indicated that OSA is associated with BMD alterations after controlling for age, gender, and cardiovascular diseases. Here, we report that OSA is associated with BMD alterations. Further studies are required to untangle the complex affect of OSA on BMD and the possible clinical implications of vertebra-depressed or femoral neck fractures.

Prevalence and effects of sleep-disordered breathing on middle-aged patients with sedative-free generalized anxiety disorder: A prospective case-control study

OBJECTIVE

Generalized anxiety disorder (GAD) and sleep-disordered breathing (SDB) share similar symptoms, such as poor sleep quality, irritability, and poor concentration during daily activities. This study aims to investigate the proportion of undiagnosed SDB and its impacts on anxiety severity and autonomic function in newly diagnosed, sedative-free GAD patients.

METHODS

This prospective case-control study included newly diagnosed GAD patients and control participants with matched age, sex, and body mass index (BMI) in Taiwan. All participants completed questionnaires for sleep and mood symptoms and a resting 5-min heart rate variability (HRV) examination during enrollment. The participants also used a home sleep apnea test to detect SDB. An oxygen desaturation index (ODI) ≥ 5 was considered indicative of SDB.

RESULTS

In total, 56 controls and 47 newly diagnosed GAD participants (mean age 55.31 ± 12.36 years, mean BMI 23.41 ± 3.42 kg/m²) were included. There was no significant difference in the proportion of undiagnosed SDB in the control and sedative-free GAD groups (46.43 vs. 51.06%). Sedative-free GAD patients with SDB scored significantly higher on Beck Anxiety Inventory (23.83 ± 11.54) than those without SDB (16.52 ± 10.61) (p < 0.001). Both control and sedative-free GAD groups with SDB had worse global autonomic function than the control group without SDB, as evidenced by the HRV results (p < 0.05 for all).

CONCLUSION

Average age 55 years and mean BMI 23 kg/m² patients with GAD and matched controls had an undiagnosed SDB prevalence of approximately 50%. SDB correlated with worsening anxiety severity and reduced cardiac autonomic function. Moreover, age and BMI were considered major risk factors for predicting undiagnosed SDB.

The relationships between obstructive sleep apnea and psychiatric disorders: a narrative review

Introduction: Obstructive sleep apnea (OSA) is the most common sleep-related breathing disorder. Its prevalence tends to increase worldwide. Untreated sleep apnea is associated with a higher risk of metabolic diseases, cardiovascular diseases, stroke, road accidents, and death, but also it is suggested that it increases the risk of mental disorders.

Method: The literature review was based on a search of articles on Medline, Pubmed, and Google Scholar from 2003 to 2021 using the keywords: obstructive sleep apnea; mental disorders; cognitive functions; affective disorders; depression; bipolar disorder; schizophrenia; psychotic disorders. The analysis included original studies, meta-analysis, and review articles.

Discussion: The result obtained from researches published so far does not allow for drawing unequivocal conclusions. There is a lot of bias present in study protocols and inclusion/exclusion criteria. Nonetheless, it seems that some disorders have a better proven correlation with OSA. Cognitive impairment, depression, and anxiety disorders are linked to OSA not only in terms of the overlapping of symptoms but also of a causal relationship. Psychotic disorders and bipolar disorders connections with OSA are confirmed, but they are not yet well understood. All correlations are found to be possibly bidirectional.

Conclusion: 1. Multiple lines of evidence increasingly point towards a bidirectional connection between OSA and mental disorders, and the cause and effect relationship between these two groups of disorders requires further research.

2. Due to reports of an increased risk of OSA with antipsychotic drugs, caution should be exercised when initiating therapy with this type of drug in patients with known risk factors for it.

3. Screening for OSA in psychiatric patients should be introduced as OSA can increase cognitive impairment, affective, and psychotic symptoms.

Awareness of obstructive sleep apnea and its effects on daily life among health professionals from Karachi, Pakistan

BACKGROUND

Sleep disturbances are be poorly documented by primary care physicians.

OBJECTIVE

Our objective for this survey was to assess the awareness level amongst medical and dental house officers, medical and dental practitioners, and ear, nose and throat specialists (ENTs) regarding OSA and its effects on daily life.

METHODS

This was a questionnaire-based survey with yes and no and true and false type questions. In order to assess knowledge, questions related to the most common signs and symptoms of OSA were selected. Questionnaires were distributed in seven medical and dental colleges in Karachi, Pakistan under graduates and above. Stratified random sampling technique was used to assess specific professionals which made a total sample size of 614. The data of this descriptive study was compiled and analyzed using SPSS version 20.

RESULTS

84% of the participants stated their awareness about OSA. After analyzing a detailed response in the form of questionnaires, an average of only 15% showed adequate knowledge of the problem in question, the rest was unaware of the pathophysiology, signs, symptoms and management of a patient suffering from OSA.

CONCLUSION

knowledge about pathophysiology of obstructive sleep apnea and its effect on daily routine work is insufficient among health professionals. It is essential to create awareness among medical and dental fraternity regarding OSA as it is often not diagnosed and treated.

Physician knowledge and attitudes towards screening and referral for obstructive sleep apnea: a mixed methods study in a tertiary care hospital

Background

Cardiovascular diseases have risen to be the top cause of mortality and morbidity globally and at a faster pace in developing countries. Obstructive sleep apnea (OSA) is an established common denominator, severely underdiagnosed, and a potentially modifiable risk factor for non-communicable diseases (NCDs). Our study is a mixed methods evaluation of knowledge and attitudes among physicians about OSA, from a tertiary care hospital in Bangalore, South India, and how it is integrated into their practice of screening and referral for OSA diagnosis and treatment.

Methods

We did an interview, semi-structured and qualitative, along with a validated questionnaire; OSAKA (Obstructive Sleep Apnea Knowledge and Attitudes). The objective of the study was to gain insights into how knowledge and attitudes about OSA reflected qualitatively in physicians’ daily practice of screening and referral for suspected OSA.

Results

The mean OSAKA knowledge score across our sample was 12.31 (± 2.7). This level of awareness was as high as other OSAKA studies that have been conducted worldwide. However, the qualitative data from interviews highlights that physicians are not regularly screening for and thinking about OSA on a daily basis, yet these clinicians discussed regularly managing other symptoms and chronic conditions strongly associated with OSA. There were five key themes across the interviews that were used to inform recommendations for improving integration of physicians’ knowledge about OSA into clinical practice.

Conclusions

Despite a relatively high knowledge score among the clinicians, it did not influence the clinician behavior to implement a screening and referral system for OSA in their daily practice. Knowledge and attitudes alone cannot change clinician behavior. Given that OSA is a modifiable risk factor for various NCDs, there is an urgent need to implement better screening and efficient referral systems for correction of OSA.

Prediction of obstructive sleep apnea: comparative performance of three screening instruments on the apnea-hypopnea index and the oxygen desaturation index

Purpose

To evaluate the performance of the NoSAS (neck, obesity, snoring, age, sex) score, the STOP-Bang (snoring, tiredness, observed apneas, blood pressure, body mass index, age, neck circumference, gender) questionnaire, and the Epworth sleepiness score (ESS) as a screening tool for obstructive sleep apnea (OSA) severity based on the apnea-hypopnea index (AHI) and the oxygen desaturation index (ODI).

Methods

Data from 235 patients who were monitored by ambulant polysomnography (PSG) were retrospectively analyzed. OSA severity was classified based on the AHI; similar classification categories were made based on the ODI. Discrimination was assessed by the area under the curve (AUC), while predictive parameters were calculated by four-grid contingency tables.

Results

The NoSAS score and the STOP-Bang questionnaire were both equally adequate screening tools for the AHI and the ODI with AUC ranging from 0.695 to 0.767 and 0.684 to 0.767, respectively. Both questionnaires perform better when used as a continuous variable. The ESS did not show adequate discrimination for screening for OSA (AUC ranging from 0.450 to 0.525). Male gender, age, and BMI proved to be the strongest individual predictors in this cohort.

Conclusion

This is the first study to evaluate the predictive performance of three different screening instruments with respect to both the AHI and the ODI. This is important, due to increasing evidence that the ODI may have a higher reproducibility in the clinical setting. The NoSAS score and the STOP-Bang questionnaire proved to be equally adequate to predict OSA severity based on both the AHI and the ODI.

Electronic supplementary material

The online version of this article (10.1007/s11325-020-02219-6) contains supplementary material, which is available to authorized users.

Awareness of obstructive sleep apnea among critical care physicians in Sharkia Governorate, Egypt

Background

Patients with symptoms of obstructive sleep apnea (OSA) present to nearly all physicians irrespective of their specialties. A basic knowledge of OSA is considered essential to identify those patients for appropriate referral and treatment. This study aimed to assess the knowledge and attitude of Sharkia Governorate Critical Care physicians regarding OSA using a standard validated questionnaire.

Results

This cross-sectional survey study was performed on a sample of Sharkia Governorate physicians, from all critical care units in tertiary and secondary hospitals including the following specialties: chest, internal medicine, neurology, cardiology, pediatric, and anesthesia. The OSA knowledge and attitudes (OSAKA) questionnaire that consists of 18 knowledge assessment questions and the OSA attitude questionnaire that consists of 6 attitude assessment questions were used. A total of 231, out of 296 invited physicians, completed the given questionnaire with a response rate of 78%. The mean score for knowledge assessment was 10.05 ± 2.3 with a 33.3% adequate response, while the mean score for attitude assessment was 3.75 ± 1.22 with a 59.3% adequate response. The mean OSA knowledge (12.5 ± 2.42) and attitude (5 ± 0.78) scores were highest among chest physicians when compared to physicians from other specialties (p < 0.001). A significant positive correlation between knowledge and attitude scores was found among Sharkia Governorate critical care physicians (r = 0.55, p < 0.001).

Conclusions

The level of knowledge of OSA among Sharkia Governorate critical care physicians was far from optimal whereas the attitude regarding OSA was acceptable.

Understanding the burden of illness of excessive daytime sleepiness associated with obstructive sleep apnea: a qualitative study

BACKGROUND

Obstructive sleep apnea (OSA) is associated with excessive daytime sleepiness (EDS), which may go undiagnosed and can significantly impair a patient's health-related quality of life (HRQOL). This qualitative research examined timing and reasons patients sought medical care for their EDS and OSA symptoms, and the impact of EDS on HRQOL.

METHODS

Focus groups were conducted in 3 US cities with 42 participants currently experiencing EDS with OSA. Transcripts were coded and analyzed using an adapted grounded theory approach common to qualitative research.

RESULTS

Over three-fifths of study participants (n = 26, 62%) were currently using a positive airway pressure (PAP) or dental device; one-third (n = 14, 33%) had previously used a positive airway pressure (PAP) or dental device, and the remainder had either used another treatment (n = 1, 2%) or were treatment naïve (n = 1, 2%). Twenty-two participants (52%) reported experiencing OSA symptoms for ≥1 year, with an average duration of 11.4 (median 8.0, range 1-37) years before seeking medical attention. Several (n = 7, 32%) considered their symptoms to be "normal," rather than signaling a serious medical condition. Thirty participants (71%) discussed their reasons for ultimately seeking medical attention, which included: input from spouse/partner, another family member, or friend (n = 20, 67%); their own concern about particular symptoms (n = 7, 23%); and/or falling asleep while driving (n = 5, 17%). For all 42 participants, HRQOL domains impacted by EDS included: physical health and functioning (n = 40, 95%); work productivity (n = 38, 90%); daily life functioning (n = 39, 93%); cognition (n = 38, 90%); social life/relationships (n = 37, 88%); and emotions (n = 30, 71%).

CONCLUSIONS

Findings suggest that patients may be unaware that their symptoms could indicate OSA requiring evaluation and treatment. Even following diagnosis, EDS associated with OSA can continue to substantially affect HRQOL and daily functioning. Further research is needed to address diagnostic delays and unmet treatment needs for patients with EDS associated with OSA.

Obstructive Sleep Apnoea Syndrome: Continuous Positive Airway Pressure Therapy for Prevention of Cardiovascular Risk

Obstructive sleep apnoea (OSA) syndrome is characterised by the presence of apnoea or obstructive hypopnoea during sleep, accompanied by hypoxia. It is estimated that the syndrome affects approximately 10% of men and 15% of women. Diagnosis and treatment rates have increased in recent years, but the condition remains undiagnosed in a high percentage of patients. Recent evidence suggests that OSA may increase the risk of cardiovascular disease. The relationship between OSA and cardiovascular disease can be explained, at least in part, by the coexistence of cardiovascular risk factors in the two pathologies, such as age, overweight, smoking and sedentary lifestyle. However, OSA has been independently associated with the risk of developing hypertension, cerebrovascular disease, ischaemic heart disease, heart failure and arrhythmias. Clinical trials that have evaluated the efficacy of continuous positive airway pressure (CPAP) treatment in primary and secondary cardiovascular prevention have not demonstrated a significant reduction in the incidence or recurrence of cardiovascular events. This article analyses the relationship between OSA and cardiovascular risk and discusses recent clinical trials on the efficacy of CPAP in primary and secondary cardiovascular prevention.

Doctor-patient sleep discussions for US adults: results from the SHADES study

OBJECTIVES

Determine the current rate of patient-provider sleep discussions and identify factors associated with occurrence of these discussions.

DESIGN

Secondary cross-sectional analysis of self-report data collected during the Sleep and Healthy Activity Diet Environment and Socialization study. Logistic regressions were used.

SETTING

Urban and suburban Southeastern Pennsylvania PARTICIPANTS: A total of n = 998 adults (aged 22-60), 38.6% female, racially and socioeconomically diverse, from urban and suburban Southeastern Pennsylvania.

MEASUREMENTS

Outcome measures were responses to 3 questions: (1) ever discussed sleep with a provider, (2) a provider ever discussed importance of sleep schedule, and (3) a provider ever discussed importance of enough sleep. Descriptive/independent variables included demographic factors and a wide range of patient-reported measures of health and sleep habits.

RESULTS

About a third of individuals have ever discussed sleep with a provider. Factors associated with higher odds of sleep-related discussions included sleep medication use, worse insomnia severity, race (Black/African American, Hispanic, Latino, other/multiracial), female sex, higher education, higher body mass index, and worse depression severity. Factors associated with lower odds were Asian race and low income. Sleep discussions were not associated with certain factors indicative of sleep disorders: sleep duration, snoring, shift work schedule, not working, and anxiety.

CONCLUSIONS

Low rates of patient-provider sleep discussions and factors associated (or not) with their occurrence indicate missed opportunities for improved health outcomes.

Sleep staging using nocturnal sound analysis

Sleep staging is essential for evaluating sleep and its disorders. Most sleep studies today incorporate contact sensors that may interfere with natural sleep and may bias results. Moreover, the availability of sleep studies is limited, and many people with sleep disorders remain undiagnosed. Here, we present a pioneering approach for rapid eye movement (REM), non-REM, and wake staging (macro-sleep stages, MSS) estimation based on sleep sounds analysis. Our working hypothesis is that the properties of sleep sounds, such as breathing and movement, within each MSS are different. We recorded audio signals, using non-contact microphones, of 250 patients referred to a polysomnography (PSG) study in a sleep laboratory. We trained an ensemble of one-layer, feedforward neural network classifiers fed by time-series of sleep sounds to produce real-time and offline analyses. The audio-based system was validated and produced an epoch-by-epoch (standard 30-sec segments) agreement with PSG of 87% with Cohen's kappa of 0.7. This study shows the potential of audio signal analysis as a simple, convenient, and reliable MSS estimation without contact sensors.

Primary care physicians' knowledge of sleep medicine and barriers to transfer of patients with sleep disorders. A cross-sectional study

OBJECTIVES

To assess primary care physicians' (PCPs) knowledge and attitudes toward sleep disorders.  Methods: In this cross-sectional quantitative study, we surveyed 88 primary care centers under the Ministry of Health during 2015 in Riyadh, Saudi Arabia, using a combination of pre-designed validated questionnaires. Knowledge was assessed using the Assessment of Sleep Knowledge in Medical Education (ASKME) questionnaire, and attitude was assessed using a pre-designed survey. For numerical variables, t-test was used, and for categorical variables, Chi-square test was used. Results: Data from 223 PCPs (males 50.2%) were analyzed. Among the participants, 44 (19.9%) did not know that sleep medicine is a distinct medical specialty, and 24 (10.9%) felt that sleep disorders are uncommon medical problems based on their daily practice. Only 87 (39%) of physicians stated that they referred patients with sleep disorders to specialized medical centers for further management. The mean score of the ASKME questionnaire was 14.4 ± 4 out of 30 (48%). The majority of physicians (78.5%) obtained a score between 11 and 20. Score results were not related to gender or years of practice. Conclusion: Primary care physicians' have a low level of awareness and poor knowledge of sleep medicine and sleep disorders.

Training, knowledge, attitudes and practices of Canadian health care providers regarding sleep and sleep disorders in children

Background

Sleep disorders are prevalent in children and are associated with significant comorbidity.

Objective

To assess the training, knowledge, attitudes and practices of Canadian health care providers (HCPs) regarding sleep disorders in children.

Method

A 42-item survey, designed to collect information on frequency of paediatric sleep disorders-related screening and diagnosis, implementation of evidence-based interventions and related knowledge base, was completed by HCPs.

Results

Ninety-seven HCPs completed the survey. One per cent obtained training in paediatric sleep during undergraduate training and 3% obtained such training during their residencies, yet 34.9% estimated that 25 to 50% of their patients suffered from sleep disorders. Most HCPs thought that sleep disorders significantly impacted children's health and daytime function. Most HCPs screened for developmental sleep issues, but not consistently for sleep disorders. Most recommended evidence-based behavioural interventions for behavioural sleep disorders, but some also reported behavioural interventions that were not first-line or recommended. Inadequate knowledge regarding melatonin use was evident. Most participants reported rarely/never ordering a sleep study for a child with suspected obstructive sleep apnea (OSA). Most were familiar with surgical and weight loss management options for OSA; many were unfamiliar with benefits of continuous positive airway pressure. Participants' knowledge scores were highest on developmental and behavioural aspects of sleep, and lowest on sleep disorders.

Conclusions

HCPs exhibit significant gaps in their knowledge, screening, evaluation and treatment practices for paediatric sleep disorders. Training at the undergraduate, graduate and postgraduate levels, as well as Continuing Medical Education are needed to optimize recognition, treatment and follow-up of paediatric sleep disorders.

Obstructive sleep apnea severity estimation: Fusion of speech-based systems

Obstructive sleep apnea (OSA) is a common sleep-related breathing disorder. Previous studies associated OSA with anatomical abnormalities of the upper respiratory tract that may be reflected in the acoustic characteristics of speech. We tested the hypothesis that the speech signal carries essential information that can assist in early assessment of OSA severity by estimating apnea-hypopnea index (AHI). 198 men referred to routine polysomnography (PSG) were recorded shortly prior to sleep onset while reading a one-minute speech protocol. The different parts of the speech recordings, i.e., sustained vowels, short-time frames of fluent speech, and the speech recording as a whole, underwent separate analyses, using sustained vowels features, short-term features, and long-term features, respectively. Applying support vector regression and regression trees, these features were used in order to estimate AHI. The fusion of the outputs of the three subsystems resulted in a diagnostic agreement of 67.3% between the speech-estimated AHI and the PSG-determined AHI, and an absolute error rate of 10.8 events/hr. Speech signal analysis may assist in the estimation of AHI, thus allowing the development of a noninvasive tool for OSA screening.

Breathing and Snoring Sound Characteristics during Sleep in Adults

STUDY OBJECTIVES

Sound level meter is the gold standard approach for snoring evaluation. Using this approach, it was established that snoring intensity (in dB) is higher for men and is associated with increased apnea-hypopnea index (AHI). In this study, we performed a systematic analysis of breathing and snoring sound characteristics using an algorithm designed to detect and analyze breathing and snoring sounds. The effect of sex, sleep stages, and AHI on snoring characteristics was explored.

METHODS

We consecutively recruited 121 subjects referred for diagnosis of obstructive sleep apnea. A whole night audio signal was recorded using noncontact ambient microphone during polysomnography. A large number (> 290,000) of breathing and snoring (> 50 dB) events were analyzed. Breathing sound events were detected using a signal-processing algorithm that discriminates between breathing and nonbreathing (noise events) sounds.

RESULTS

Snoring index (events/h, SI) was 23% higher for men (p = 0.04), and in both sexes SI gradually declined by 50% across sleep time (p < 0.01) independent of AHI. SI was higher in slow wave sleep (p < 0.03) compared to S2 and rapid eye movement sleep; men have higher SI in all sleep stages than women (p < 0.05). Snoring intensity was similar in both genders in all sleep stages and independent of AHI. For both sexes, no correlation was found between AHI and snoring intensity (r = 0.1, p = 0.291).

CONCLUSIONS

This audio analysis approach enables systematic detection and analysis of breathing and snoring sounds from a full night recording. Snoring intensity is similar in both sexes and was not affected by AHI.

Diagnostic accuracy of the Berlin questionnaire, STOP-BANG, STOP, and Epworth sleepiness scale in detecting obstructive sleep apnea: A bivariate meta-analysis

Obstructive sleep apnea (OSA) is a highly prevalent sleep disorder; however, it remains underdiagnosed and undertreated. Although screening tools such as the Berlin questionnaire (BQ), STOP-BANG questionnaire (SBQ), STOP questionnaire (STOP), and Epworth sleepiness scale (ESS) are widely used for OSA, the findings regarding their diagnostic accuracy are controversial. Therefore, this meta-analysis investigated and compared the summary sensitivity, specificity, and diagnostic odds ratio (DOR) among the BQ, SBQ, STOP, and ESS according to the severity of OSA. Electronic databases, namely the Embase, PubMed, PsycINFO, ProQuest dissertations and theses A&I databases, and China knowledge resource integrated database, were searched from their inception to July 15, 2016. We included studies examining the sensitivity and specificity of the BQ, SBQ, STOP, and ESS against the apnea-hypopnea index (AHI) or respiratory disturbance index (RDI). The revised quality assessment of diagnostic accuracy studies was used to evaluate the methodological quality of studies. A random-effects bivariate model was used to estimate the summary sensitivity, specificity, and DOR of the tools. We identified 108 studies including a total of 47 989 participants. The summary estimates were calculated for the BQ, SBQ, STOP, and ESS in detecting mild (AHI/RDI ≥ 5 events/h), moderate (AHI/RDI ≥ 15 events/h), and severe OSA (AHI/RDI ≥ 30 events/h). The performance levels of the BQ, SBQ, STOP, and ESS in detecting OSA of various severity levels are outlined as follows: for mild OSA, the pooled sensitivity levels were 76%, 88%, 87%, and 54%; pooled specificity levels were 59%, 42%, 42%, and 65%; and pooled DORs were 4.30, 5.13, 4.85, and 2.18, respectively. For moderate OSA, the pooled sensitivity levels were 77%, 90%, 89%, and 47%; pooled specificity levels were 44%, 36%, 32%, and 621%; and pooled DORs were 2.68, 5.05, 3.71, and 1.45, respectively. For severe OSA, the pooled sensitivity levels were 84%, 93%, 90%, and 58%; pooled specificity levels were 38%, 35%, 28%, and 60%; and pooled DORs were 3.10, 6.51, 3.37, and 2.10, respectively. Therefore, for mild, moderate, and severe OSA, the pooled sensitivity and DOR of the SBQ were significantly higher than those of other screening tools (P < .05); however, the specificity of the SBQ was lower than that of the ESS (P < .05). Moreover, age, sex, body mass index, study sample size, study populations, presence of comorbidities, PSG or portable monitoring performance, and risk of bias in the domains of the index test and reference standard were significant moderators of sensitivity and specificity (P < .05). Compared with the BQ, STOP, and ESS, the SBQ is a more accurate tool for detecting mild, moderate, and severe OSA. Sleep specialists should use the SBQ to conduct patient interviews for the early diagnosis of OSA in clinical settings, particularly in resource-poor countries and sleep clinics where PSG is unavailable.

Examining uptake of online education on obstructive sleep apnoea in general practitioners: a randomised trial

Background

Obstructive sleep apnoea (OSA) affects up to 28 % of the adult population in Western countries. The detection and management of OSA by general practitioners (GPs) can be poor. The study aimed to examine what influence enhanced invitations had on uptake of on-line learning modules for OSA by GPs, and whether recent referrals of patients to sleep specialists influenced uptake.

Methods

Practicing GPs in regional Australia were identified and randomised to receive either an enhanced or standard invitation letter to a new on-line education module for OSA. The enhanced letter included indication that the module was eligible for professional accreditation and described the prevalence and burden of sleep disorders. Some included extra emphasis if the GP had recently referred a patient for diagnostic investigation of OSA. Two reminder letters were sent.

Results

Of 796 eligible GPs who received the letters, sixteen (2 %) accessed the website and four completed the modules over the four-month study period. GPs who received an enhanced invitation letter were not significantly more likely to access the website compared to GPs who received the standard invitation letter. Recent referral of a patient for diagnostic investigation was also not a significant factor in influencing use of the module.

Conclusion

GP interest in on-line education about OSA appears low, and emphasis of relevant recent past patient(s) and the opportunity for professional education points was not successful in increasing engagement. There is a need to identify effective approaches to improving the detection and management of OSA in general practice.

A Collaborative Paradigm for Improving Management of Sleep Disorders in Primary Care: A Randomized Clinical Trial

OBJECTIVES

To test a collaborative care model for interfacing sleep specialists with primary care providers to enhance patients' sleep disorders management.

METHODS

This study used a randomized, parallel group, clinical intervention trial design. A total of 137 adult (29 women) VA outpatients with sleep complaints were enrolled and randomly assigned to (1) an intervention (INT) consisting of a one-time consultation with a sleep specialist who provided diagnostic feedback and treatment recommendations to the patient and the patient's primary care provider; or (2) a control condition consisting of their usual primary care (UPC). Provider-focused outcomes included rates of adherence to recommended diagnostic procedures and sleep-focused interventions. Patient-focused outcomes included measures taken from sleep diaries and actigraphy; Pittsburgh Sleep Quality Index (PSQI) scores; and self-report measures of sleepiness, fatigue, mood, quality of life, and satisfaction with health care.

RESULTS

The proportions of provider-initiated sleep-focused interventions were significantly higher in the INT group than in the UPC group for polysomnography referrals (49% versus 6%; P < 0.001) and mental health clinic referrals (19% versus 6%; P = 0.02). At the 10-mo follow up, INT recipients showed greater estimated mean reductions in diary total wake time (-17.0 min; 95% confidence interval [CI]: -30.9, -3.1; P = 0.02) and greater increases in sleep efficiency (+3.7%; 95% CI: 0.8, 6.5; P = 0.01) than did UPC participants. A greater proportion of the INT group showed ≥ 1 standard deviation decline on the PSQI from baseline to the 10-mo follow-up (41% versus 21%; P = 0.02). Moreover, 69% of the INT group had normal (≤ 10) Epworth Sleepiness Scale scores at the 10-mo follow-up, whereas only 50% of the UPC group fell below this clinical cutoff (P = 0.03).

CONCLUSIONS

A one-time sleep consultation significantly increased healthcare providers' attention to sleep problems and resulted in benefits to patients' sleep/wake symptoms.

CLINICAL TRIALS REGISTRATION

This study is registered with clinicaltrials.gov with identifier # NCT00390572.

The effect of physician continuing medical education on patient-reported outcomes for identifying and optimally managing obstructive sleep apnea

STUDY OBJECTIVE

To evaluate the effect of continuing medical education (CME) activities on patient reported outcomes with regard to (1) screening for excessive sleepiness (ES) and obstructive sleep apnea (OSA) and (2) appropriate referral and treatment.

METHODS

A total of 725 patients were recruited from 75 providers who either participated or did not participate in Transtheoretical Model (TTM)-based OSA CME activities. Patient reported outcomes from participating (n = 36) and non-participating providers (n = 39) were compared using generalized estimating equations examining random effects of provider as unit of assignment.

RESULTS

Patients' reports demonstrate that participating physicians were 1.7 times more likely to initiate discussion of sleep problems than non-participating physicians (t1,411 = 3.71, p = 0.05) and 2.25-2.86 times more likely to administer validated measures for OSA (Epworth Sleepiness Scale and STOP-BANG). Patient reports also indicated that participating clinicians (79.9%) were significantly more likely to recommend seeing a sleep specialist compared to non-participating clinicians (60.7%; t1,348 = 9.1, p < 0.01, OR = 2.6). Furthermore, while 89.4% of participating clinicians recommended a sleep study, only 73.2% of the non-participating physicians recommended one (t1,363 = 11.46, p < 0.001, OR = 3.1).

CONCLUSIONS

Participation in TTM-based OSA CME activities was associated with improved patient reported outcomes compared to the non-participating clinicians.

Sleep-wake evaluation from whole-night non-contact audio recordings of breathing sounds

STUDY OBJECTIVES

To develop and validate a novel non-contact system for whole-night sleep evaluation using breathing sounds analysis (BSA).

DESIGN

Whole-night breathing sounds (using ambient microphone) and polysomnography (PSG) were simultaneously collected at a sleep laboratory (mean recording time 7.1 hours). A set of acoustic features quantifying breathing pattern were developed to distinguish between sleep and wake epochs (30 sec segments). Epochs (n = 59,108 design study and n = 68,560 validation study) were classified using AdaBoost classifier and validated epoch-by-epoch for sensitivity, specificity, positive and negative predictive values, accuracy, and Cohen's kappa. Sleep quality parameters were calculated based on the sleep/wake classifications and compared with PSG for validity.

SETTING

University affiliated sleep-wake disorder center and biomedical signal processing laboratory.

PATIENTS

One hundred and fifty patients (age 54.0±14.8 years, BMI 31.6±5.5 kg/m2, m/f 97/53) referred for PSG were prospectively and consecutively recruited. The system was trained (design study) on 80 subjects; validation study was blindly performed on the additional 70 subjects.

MEASUREMENTS AND RESULTS

Epoch-by-epoch accuracy rate for the validation study was 83.3% with sensitivity of 92.2% (sleep as sleep), specificity of 56.6% (awake as awake), and Cohen's kappa of 0.508. Comparing sleep quality parameters of BSA and PSG demonstrate average error of sleep latency, total sleep time, wake after sleep onset, and sleep efficiency of 16.6 min, 35.8 min, and 29.6 min, and 8%, respectively.

CONCLUSIONS

This study provides evidence that sleep-wake activity and sleep quality parameters can be reliably estimated solely using breathing sound analysis. This study highlights the potential of this innovative approach to measure sleep in research and clinical circumstances.

The economic impact of obstructive sleep apnea

PURPOSE OF REVIEW

Obstructive sleep apnea (OSA) has a substantial economic impact on healthcare systems. We reviewed parameters affecting healthcare costs (race, low education, and socioeconomic status) on OSA comorbidity, and costs and the effect of OSA treatment on medical costs.

RECENT FINDINGS

OSA is associated with increased cardiovascular disease (CVD) morbidity and substantially increased medical costs. Risk for OSA and resulting CVD are associated with obesity, tobacco smoking, black race, and low socioeconomic status; all these are associated with poor continuous positive airway pressure (CPAP) adherence. Healthcare costs are not normally distributed, that is, the costliest and the sickest upper third of patients consume 65-82% of all medical costs. Only a limited number of studies have explored the effect of CPAP on medical costs.

SUMMARY

Costs of untreated OSA may double the medical expenses mainly because of CVD. Identifying the costliest, sickest upper third of OSA patients will reduce expenses to healthcare systems. Studies exploring the effect of CPAP on medical costs are essential. In addition, tailoring intervention programs to reduce barriers to adherence have the potential to improve CPAP treatment, specially in at-risk populations that are sicker and consume more healthcare costs.

The Effect of the Transition to Home Monitoring for the Diagnosis of OSAS on Test Availability, Waiting Time, Patients' Satisfaction, and Outcome in a Large Health Provider System

During 2009, the Haifa district of Clalit Health Services (CHS) has switched from in-lab polysomnography (PSG) to home studies for the diagnosis of obstructive sleep apnea (OSA). We assessed the effects of this change on accessibility, waiting time, satisfaction, costs, and CPAP purchase by the patients. Data regarding sleep studies, CPAP purchase, and waiting times were collected retrospectively from the computerized database of CHS. Patients' satisfaction was assessed utilizing a telephone questionnaire introduced to a randomized small sample of 70 patients. Comparisons were made between 2007 and 2008 (in-lab PSGs) and 2010 and 2011 (when most studies were ambulatory). Of about 650000 insured individuals in the Haifa district of CHS, 1471 sleep studies were performed during 2007-2008 compared to 2794 tests during 2010-2011. The average waiting time was 9.9 weeks in 2007-2008 compared to 1.1 weeks in 2010-2011 (P < 0.05). 597 CPAPs were purchased in 2007-2008 compared to 831 in 2010-2011. The overall patients' satisfaction was similar, but discomfort tended to be higher in the in-laboratory group (4.1 vs 2.7 in a scale of 0-10; P = 0.11). Switching to ambulatory diagnosis improved the test accessibility and reduced the waiting times. Patients' satisfaction remained similarly high. The total direct cost of OSA management was reduced.

Major care gaps in asthma, sleep and chronic obstructive pulmonary disease: a road map for knowledge translation

Large gaps between best evidence-based care and actual clinical practice exist in respiratory medicine, and carry a significant health burden. The authors reviewed two key care gaps in each of asthma, chronic obstructive pulmonary disease and obstructive sleep apnea. Using the 'Knowledge-to-Action Framework', the nature of each gap, its magnitude, the barriers that cause and perpetuate it, and past and future strategies that might address the problem were considered. In asthma: disease control is ascertained inadequately, leading to a prevalence of poor asthma control of approximately 50%; and asthma action plans, a key component of asthma management, are provided by only 22% of physicians. In obstructive sleep apnea: disease is under-recognized, with sleep histories ascertained in only 10% of patients; and Canadian polysomnography wait times remain longer than recommended, leading to unnecessary morbidity and societal cost. In chronic obstructive pulmonary disease: a large proportion of patients seen in primary care remain undiagnosed, mainly due to underuse of spirometry; and <10% of patients are referred for pulmonary rehabilitation, despite strong evidence demonstrating its cost effectiveness. Given the prevalence of these chronic conditions and the size and nature of these gaps, the latter exact an important toll on patients, the health care system and society. In turn, complex barriers at the patient, provider and health care system levels contribute to each gap. There have been few previous attempts to bridge these gaps. Innovative and multifaceted implementation approaches are needed and have the potential to make a large impact on Canadian respiratory health.

Diagnostic accuracy of level 3 portable sleep tests versus level 1 polysomnography for sleep-disordered breathing: a systematic review and meta-analysis

BACKGROUND

Greater awareness of sleep-disordered breathing and rising obesity rates have fueled demand for sleep studies. Sleep testing using level 3 portable devices may expedite diagnosis and reduce the costs associated with level 1 in-laboratory polysomnography. We sought to assess the diagnostic accuracy of level 3 testing compared with level 1 testing and to identify the appropriate patient population for each test.

METHODS

We conducted a systematic review and meta-analysis of comparative studies of level 3 versus level 1 sleep tests in adults with suspected sleep-disordered breathing. We searched 3 research databases and grey literature sources for studies that reported on diagnostic accuracy parameters or disease management after diagnosis. Two reviewers screened the search results, selected potentially relevant studies and extracted data. We used a bivariate mixed-effects binary regression model to estimate summary diagnostic accuracy parameters.

RESULTS

We included 59 studies involving a total of 5026 evaluable patients (mostly patients suspected of having obstructive sleep apnea). Of these, 19 studies were included in the meta-analysis. The estimated area under the receiver operating characteristics curve was high, ranging between 0.85 and 0.99 across different levels of disease severity. Summary sensitivity ranged between 0.79 and 0.97, and summary specificity ranged between 0.60 and 0.93 across different apnea-hypopnea cut-offs. We saw no significant difference in the clinical management parameters between patients who underwent either test to receive their diagnosis.

INTERPRETATION

Level 3 portable devices showed good diagnostic performance compared with level 1 sleep tests in adult patients with a high pretest probability of moderate to severe obstructive sleep apnea and no unstable comorbidities. For patients suspected of having other types of sleep-disordered breathing or sleep disorders not related to breathing, level 1 testing remains the reference standard.

Automatic detection of whole night snoring events using non-contact microphone

Objective

Although awareness of sleep disorders is increasing, limited information is available on whole night detection of snoring. Our study aimed to develop and validate a robust, high performance, and sensitive whole-night snore detector based on non-contact technology.

Design

Sounds during polysomnography (PSG) were recorded using a directional condenser microphone placed 1 m above the bed. An AdaBoost classifier was trained and validated on manually labeled snoring and non-snoring acoustic events.

Patients

Sixty-seven subjects (age 52.5±13.5 years, BMI 30.8±4.7 kg/m², m/f 40/27) referred for PSG for obstructive sleep apnea diagnoses were prospectively and consecutively recruited. Twenty-five subjects were used for the design study; the validation study was blindly performed on the remaining forty-two subjects.

Measurements and Results

To train the proposed sound detector, >76,600 acoustic episodes collected in the design study were manually classified by three scorers into snore and non-snore episodes (e.g., bedding noise, coughing, environmental). A feature selection process was applied to select the most discriminative features extracted from time and spectral domains. The average snore/non-snore detection rate (accuracy) for the design group was 98.4% based on a ten-fold cross-validation technique. When tested on the validation group, the average detection rate was 98.2% with sensitivity of 98.0% (snore as a snore) and specificity of 98.3% (noise as noise).

Conclusions

Audio-based features extracted from time and spectral domains can accurately discriminate between snore and non-snore acoustic events. This audio analysis approach enables detection and analysis of snoring sounds from a full night in order to produce quantified measures for objective follow-up of patients.

The diagnostic yield of pediatric polysomnography based on the professional background of referring physicians

INTRODUCTION

Polysomnography (PSG) is the gold standard in diagnosis of sleep-disordered breathing but is labor intensive and expensive. We assessed PSG outcomes based on physician specialty and whether prior referral to sleep clinics reduces costs for children with sleep problems.

METHODS

Retrospective analysis of PSGs was performed by demographics, physician specialization, PSG indication, and results. Average costs of evaluating PSGs ordered by primary care physicians (PCPs) versus initial referral to sleep specialists were compared.

RESULTS

A total of 493 PSGs were performed between June 2010 and December 2010. Most referrals came from sleep physicians (31%), otolaryngologists (24%), and PCPs (18%). Forty-four percent PSGs ordered by PCPs were normal versus 22% by sleep physicians (odds ratio = 2.8, P < .05). Average cost of PSGs ordered by PCPs was $3053.54/patient versus $917.85/patient for sleep specialist referral.

CONCLUSION

PSGs ordered by PCPs were more likely to be normal than PSGs by sleep physicians. Sleep clinic assessment before PSGs may assist in appropriate service utilization, improve delivery of care, and reduce health care costs by using these tests appropriately.

Sleeping over a sleep disorder - Awareness of obstructive sleep apnoea as a modifiable risk factor for hypertension and stroke: A survey among health care professionals and medical students

Background:

Obstructive sleep apnoea (OSA) syndrome is an established and modifiable but under recognized risk factor for common disorders like stroke and hypertension.

Objective:

To assess awareness level of health care practitioners and medical students about OSA as a risk factor for stroke and hypertension.

Methods:

Questionnaire based survey with multiple response type and fill in the blanks type questions. The data was compiled and analyzed using SPSS version 19.

Results:

180 participants completed the survey questionnaire. Only 24 (13.3%) identified OSA as a reversible risk factor for ischemic stroke. 11 (6%) participants only could answer OSA as an identified risk factor for hypertension as per Seventh Joint National Committee report.

Conclusion:

This study reveals dismal level of awareness, among health professionals and medical students, about OSA being an established and modifiable risk factor for hypertension and ischemic stroke.

Obstructive sleep apnea and multimorbidity

Background

Obstructive sleep apnea (OSA) is becoming increasingly prevalent in North America and has been described in association with specific chronic diseases, particularly cardiovascular diseases. In primary care, where the prevalence of co-occurring chronic conditions is very high, the potential association with OSA is unknown. The purpose of this study was to explore the association between OSA and 1) the presence and severity of multimorbidity (multiple co-occurring chronic conditions), and 2) subcategories of multimorbidity.

Methods

A cluster sampling technique was used to recruit 120 patients presenting with OSA of various severities from the records of a sleep laboratory in 2008. Severity of OSA was based on the results of the polysomnography. Patients invited to participate received a mail questionnaire including questions on sociodemographic characteristics and the Disease Burden Morbidity Assessment (DBMA). They also consented to give access to their medical records. The DBMA was used to provide an overall multimorbidity score and sub-score of diseases affecting various systems.

Results

Bivariate analysis did not demonstrate an association between OSA and multimorbidity (r = 0.117; p = 0.205). However, severe OSA was associated with multimorbidity (adjusted odds ratio = 7.33 [1.67-32.23], p = 0.05). OSA was moderately correlated with vascular (r = 0.26, p = 0.01) and metabolic syndrome (r = 0.26, p = 0.01) multimorbidity sub-scores.

Conclusions

This study showed that severe OSA is associated with severe multimorbidity and sub-scores of multimorbidity. These results do not allow any causal inference. More research is required to confirm these associations. However, primary care providers should be aware of these potential associations and investigate OSA when deemed appropriate.

Obstructive apnea hypopnea index estimation by analysis of nocturnal snoring signals in adults

STUDY OBJECTIVE

To develop a whole-night snore sounds analysis algorithm enabling estimation of obstructive apnea hypopnea index (AHI(EST)) among adult subjects.

DESIGN

Snore sounds were recorded using a directional condenser microphone placed 1 m above the bed. Acoustic features exploring intra-(mel- cepstability, pitch density) and inter-(running variance, apnea phase ratio, inter-event silence) snore properties were extracted and integrated to assess AHI(EST).

SETTING

University-affiliated sleep-wake disorder center and biomedical signal processing laboratory.

PATIENTS

Ninety subjects (age 53 ± 13 years, BMI 31 ± 5 kg/m(2)) referred for polysomnography (PSG) diagnosis of OSA were prospectively and consecutively recruited. The system was trained and tested on 60 subjects. Validation was blindly performed on the additional 30 consecutive subjects.

MEASUREMENTS AND RESULTS

AHI(EST) correlated with AHI (AHI(PSG); r(2) = 0.81, P < 0.001). Area under the receiver operating characteristic curve of 85% and 92% for thresholds of 10 and 20 events/h, respectively, were obtained for OSA detection. Both Altman-Bland analysis and diagnostic agreement criteria revealed 80% and 83% agreements of AHI(EST) with AHI(PSG), respectively.

CONCLUSIONS

Acoustic analysis based on intra- and inter-snore properties can differentiate subjects according to AHI. An acoustic-based screening system may address the growing needs for reliable OSA screening tool. Further studies are needed to support these findings.

Financial incentive increases CPAP acceptance in patients from low socioeconomic background

Objective

We explored whether financial incentives have a role in patients′ decisions to accept (purchase) a continuous positive airway pressure (CPAP) device in a healthcare system that requires cost sharing.

Design

Longitudinal interventional study.

Patients

The group receiving financial incentive (n = 137, 50.8±10.6 years, apnea/hypopnea index (AHI) 38.7±19.9 events/hr) and the control group (n = 121, 50.9±10.3 years, AHI 39.9±22) underwent attendant titration and a two-week adaptation to CPAP. Patients in the control group had a co-payment of $330–660; the financial incentive group paid a subsidized price of $55.

Results

CPAP acceptance was 43% greater (p = 0.02) in the financial incentive group. CPAP acceptance among the low socioeconomic strata (n = 113) (adjusting for age, gender, BMI, tobacco smoking) was enhanced by financial incentive (OR, 95% CI) (3.43, 1.09–10.85), age (1.1, 1.03–1.17), AHI (>30 vs. <30) (4.87, 1.56–15.2), and by family/friends who had positive experience with CPAP (4.29, 1.05–17.51). Among average/high-income patients (n = 145) CPAP acceptance was affected by AHI (>30 vs. <30) (3.16, 1.14–8.75), living with a partner (8.82, 1.03–75.8) but not by the financial incentive. At one-year follow-up CPAP adherence was similar in the financial incentive and control groups, 35% and 39%, respectively (p = 0.82). Adherence rate was sensitive to education (+yr) (1.28, 1.06–1.55) and AHI (>30 vs. <30) (5.25, 1.34–18.5).

Conclusions

Minimizing cost sharing reduces a barrier for CPAP acceptance among low socioeconomic status patients. Thus, financial incentive should be applied as a policy to encourage CPAP treatment, especially among low socioeconomic strata patients.

Assessing the prioritization of primary care referrals for polysomnograms

STUDY OBJECTIVE

The mortality attributed to obstructive sleep apnea (OSA) is comparable to that of breast cancer and colon cancer. We sought to determine if patients at high risk for OSA were less likely to be referred by their primary care physician for polysomnograms (PSG) than mammograms or endoscopies.

DESIGN

Prospective cohort study; patients were recruited between January 2007 and April 2007.

SETTING

Academic public hospital system

PATIENTS

395 patients waiting for family or internal medicine primary care appointments were administered the Berlin questionnaire. Chart abstraction or interview determined demographics; insurance and employment status; body mass index (BMI); comorbidities; and prior PSG, mammography, or endoscopy referrals.

RESULTS

Mean BMI was 30 +/- 7.4 kg/m2; 187 (47%) patients had high-risk Berlin scores. Overall, 19% of patients with high-risk Berlin scores were referred for PSG, compared to 63% of those eligible for mammograms and 80% of those eligible for endoscopies. Women (OR = 2.9, P = 0.02), COPD (OR = 4.6, P = 0.03), high-risk Berlin scores (OR = 3.4, P = 0.009), and higher BMI (OR = 1.1, P < 0.001) were positively associated with PSG referrals. Privately insured patients were less likely to be referred than uninsured patients (OR = 0.3, P = 0.04). There was no significant difference in referrals among those with other forms of insurance. Race was not associated with PSG referrals.

CONCLUSION

In a public hospital, primary care patients were less likely to be referred for PSG compared to mammogram and endoscopy. Uninsured patients were more likely to be referred for PSG than those with private insurance. Further studies are needed to address the low PSG referral rates in high-risk populations.

Excessive sleepiness: under-recognized and essential marker for sleep/wake disorder management

BACKGROUND

Research during the past few decades has provided substantial evidence indicating that excessive sleepiness (ES) and associated sleep/wake disorders can result in significant morbidity and mortality. However, symptomatology (e.g., ES) and the relationships among common morbidities (e.g., cardiovascular disease, metabolic disorders, mood impairment) and sleep/wake disorders remain under-recognized in clinical practice, particularly in primary care. Yet assessment of sleep/wakefulness and associated symptoms can often be easily conducted in the primary care setting, providing valuable information to facilitate the diagnosis and management of sleep/wake disorders.

OBJECTIVE

To provide a conceptual and educational framework that helps primary care physicians comprehensively assess, differentially diagnosis, and appropriately manage patients presenting with ES or ES-related sleep/wake disorders.

METHODS

Comprised of six sleep specialists and six primary care physicians, the Sleep/Wake Disorders Working Group (SWG) used a modified, two-round Delphi approach to create and harmonize consensus recommendations for the assessment, diagnosis, treatment, and ongoing management of patients with common sleep/wake disorders related to ES.

RESULTS

After a review of the relevant literature, the SWG arrived at consensus on a number of clinical recommendations for the assessment and management ES and some of the most commonly associated sleep/wake disorders. Ten consensus statements – five each for assessment/diagnosis and treatment/ongoing care – were created for ES, insomnia, obstructive sleep apnea, circadian rhythm disorders, restless legs syndrome, and narcolepsy.

CONCLUSION

ES and ES-related sleep/wake disorders are commonly encountered in the primary care setting. By providing an educational framework for primary care physicians, the SWG hopes to improve patient outcomes by emphasizing recognition, prompt diagnosis, and appropriate ongoing management of ES and associated sleep/wake disorders.

The utility of single-channel nasal airflow pressure transducer in the diagnosis of OSA at home

RATIONALE

Given the high prevalence of obstructive sleep apnea (OSA) and the demand on polysomnography (PSG), there is a need for low cost accurate simple diagnostic modalities that can be easily deployed in primary care to improve access to diagnosis.

STUDY OBJECTIVES

The aim was to examine the utility of single-channel nasal airflow monitoring using a pressure transducer at home in patients with suspected OSA.

DESIGN

Cross-sectional study

SETTING

Laboratory and home

PARTICIPANTS

The study was conducted in two populations. Consecutive patients with suspected OSA were recruited from the sleep disorders clinic at a tertiary referral center and from 6 local metropolitan primary care centers.

INTERVENTIONS

All patients answered questionnaires and had laboratory PSG. Nasal airflow was monitored for 3 consecutive nights at home in random order either before or after PSG.

RESULTS

Atotal of 193 patients participated (105 sleep clinic patients and 88 from primary care). The mean bias PSG apnea hypopnea index (AHI) minus nasal flow respiratory disturbance index (NF RDI) was -4.9 events per hour with limits of agreement (2 SD) of 27.8. NF RDI monitored over 3 nights had high accuracy for diagnosing both severe OSA (defined as PSG AHI > 30 events per hour) with area under the receiver operating characteristic curve (AUC) 0.92 (95% confidence interval (CI) 0.88-0.96) and any OSA (PSG AHI > 5), AUC 0.87 (95% CI 0.80-0.94).

CONCLUSIONS

Single-channel nasal airflow can be implemented as an accurate diagnostic tool for OSA at home in both primary care and sleep clinic populations.

Economic implications of sleep disorders

Sleep disorders such as insomnia, obstructive sleep apnoea (OSA), excessive daytime sleepiness (EDS) and fatigue, sleep deprivation and restless legs syndrome (RLS) are increasingly seen in clinical practice. Sleep is considered vital for preserving daytime cognitive function and physiological well-being. Sleep insufficiency may have deleterious effects on work-life balance, overall health and safety. The consequential economic burden at both the individual and societal levels is significant. Moreover, sleep disorders are commonly associated with other major medical problems such as chronic pain, cardiovascular disease, mental illness, dementias, gastrointestinal disorders and diabetes mellitus. Thus, in order to properly care for patients presenting with sleep-related morbidity, and to reduce the consequential economic burden, accurate screening efforts and efficacious/cost-effective treatments need to be developed and employed.

Sleep disorder symptoms are common and unspoken in Canadian general practice

OBJECTIVE

Primary care patients were surveyed for what sleep disorder symptoms they discussed with their physicians. Their responses were compared with those of new Sleep clinic patients. The goal was to discover what symptom presentation leads to a successful referral to a sleep clinic.

METHODS

We recruited two samples: 191 older Primary care patients and 138 Sleep clinic patients. Participants completed the Sleep Symptom Checklist (SSC). This consists of 21 symptoms in four domains: insomnia, sleep disorder, daytime symptoms and psychological distress. All respondents indicated which symptoms had been discussed with their physician in the past year. Primary care subjects were designated as Decliners (completed SSC, refused further evaluation), Dropouts [completed some evaluation steps, but not polysomnography (PSG)] and Completers (completed PSG).

RESULTS

Primary care participants frequently had symptoms but relatively few had discussed them with their doctor. Sleep clinic participants discussed significantly more symptoms with their referring physician than did Primary care Dropouts or Decliners in all categories except psychological distress. Primary care Completers, 88.5% of whom were ultimately diagnosed with sleep apnoea/hypopnoea syndrome and/or periodic limb movement disorder, also discussed their sleep disorder symptoms less frequently than did Sleep clinic patients but tended to give more prominence to symptoms of insomnia and impaired daytime function.

CONCLUSIONS

The findings suggest that Primary care patients often have symptoms they do not discuss, even when a primary sleep disorder exists. The brief SSC checklist, developed in our laboratory, has potential to improve the referral rates of older primary care patients who have sleep disorder.