The medical cost of undiagnosed sleep apnea

Prevalence of high-risk group for obstructive sleep apnea using the STOP-Bang questionnaire and its association with cardiovascular morbidity

Objectives

Obstructive sleep apnea (OSA) is a common sleep-related breathing disorder, yet many cases remain undiagnosed. The STOP-Bang questionnaire was developed to identify individuals at high risk of OSA. We aimed to investigate the prevalence of individuals with suspected OSA using the STOP-Bang risk stratification in the general population of South Korea. Additionally, we determined if the STOP-Bang risk stratification independently predicts cardiovascular morbidity.

Methods

Data from the eighth Korea National Health and Nutrition Examination Survey (2019-2020) were used. Participants aged ≥40 with complete data for STOP-Bang questionnaire were included. A STOP-Bang score of ≥5 classified individuals as high-risk whereas scores of 3-4 and less than 3 classified them as intermediate- and low-risk, respectively. The association between the high-risk group and cardiovascular morbidity was analyzed using complex sample logistic regression.

Results

Among the 6,630 participants included, approximately 6.7% were classified as high-risk based on the STOP-Bang questionnaire. The prevalence of diagnosed OSA in the high-risk group was 4.0%. The high-risk group showed a significantly higher prevalence of cardiovascular morbidity (11.9%) compared to those in the low- and intermediate-risk groups (3.0 and 8.1%, respectively). After adjusting for variables associated with cardiovascular risk, the high-risk group remained an independent predictor of increased likelihood of cardiovascular morbidity compared to the low-risk group (odds ratio, 2.05; p = 0.002). When stratified by sex, STOP-Bang high-risk was significantly associated with cardiovascular morbidity in men; however, the same trend was not observed in women.

Conclusion

We found a significant proportion of individuals at high risk of OSA is likely to remain undiagnosed in the general population of South Korea. The high-risk group demonstrated a higher burden of cardiovascular morbidity, and the STOP-Bang high-risk group was an independent predictor of cardiovascular morbidity.

Cost-effectiveness and safety of continuous pulse oximetry for management of undiagnosed obstructive sleep apnea in bariatric surgery: a nationwide cohort study

BACKGROUND

Undetected obstructive sleep apnea (OSA) is highly prevalent in patients undergoing bariatric surgery and increases perioperative risks. Screening for OSA using preoperative polygraphy (PG) with subsequent continuous positive airway pressure (CPAP) is costly and time-consuming. Postoperative continuous pulse oximetry (CPOX) is less invasive, and is hypothesized to be a safe and cost-effective alternative.

OBJECTIVES

This nationwide multicenter prospective observational cohort study compared CPOX monitoring with OSA-screening using PG.

SETTING

High-volume bariatric centers.

METHODS

Patients were either postoperatively monitored using CPOX without preoperative OSA-screening, or underwent preoperative PG and CPAP treatment when OSA was diagnosed. Cohort placement was based on local hospital protocols. Cost-effectiveness was analyzed using quality adjusted life years (QALYs) and healthcare costs. Surgical outcomes were also analyzed. Propensity score matching was used in sensitivity analyses.

RESULTS

A total of 1390 patients were included. QALYs were similar between groups at baseline and 1-year postoperatively. Postoperative complications, intensive care unit (ICU)-admissions and admissions, particularly OSA-related, did not differ between groups. Mean costs per patient/year in the CPOX group was €3094 versus €3680 in the PG group; mean difference €-586 (95% CI €-933-€-242). Following propensity score matching, 1090 of 1390 included patients remained, and similar findings for cost-effectiveness, complications, and ICU admissions were observed.

CONCLUSION

CPOX monitoring without preoperative OSA-screening was not associated with higher complication or readmission rates compared to PG. CPOX resulted in lower costs from a healthcare perspective and can therefore be considered a cost-effective alternative to routine OSA-screening in patients undergoing bariatric surgery.

The association between obstructive sleep apnea and osteoporosis: A systematic review and meta-analysis

Obstructive sleep apnea (OSA) is a sleep disorder with well-known metabolic consequences. The relationship between OSA and bone health, especially osteoporosis, remains poorly understood. Given that both OSA and osteoporosis are highly prevalent chronic conditions with significant public health implications, this study aims to investigate the association of OSA with bone health and osteoporosis. A systematic search of PubMed, Embase and Cochrane Library was conducted from inception to November 22, 2022. Fifteen studies comprising 158,273 individuals were included. The presence of OSA correlated negatively with bone mineral density on meta-analysis (pooled correlation = -0.30; 95 % CI, -0.42 to -0.17; N = 8). Individuals with OSA had poorer bone mineral density scores (mean difference = -0.58, 95 % CI, -1.15 to -0.01; N = 8), and significantly higher risk of developing osteoporosis (adjusted odds ratio = 2.18; 95 % CI, 1.14 to 4.16; N = 4). Notably, both body mass index (BMI) and age were not significant effect modulators in the correlation of OSA and bone density. These findings suggest that OSA is associated with diminished bone health, and it is severity-dependent. Further studies are required to determine if treatment of OSA may have the potential to mitigate these risks.

Achieving adherence to positive airway pressure in commercial drivers using an employer-mandated remote management programme

Background

Obstructive sleep apnoea (OSA) is common in commercial drivers, and associated with increased risk of crashes if untreated, making diagnosis and effective treatment crucial in this population.

Study design and methods

This is a retrospective summary of a clinical programme based on telemedicine and remote treatment monitoring developed with a national trucking company to screen new hires in the USA for OSA and implement positive airway pressure (PAP) management. New hires were informed of the programme and consented as part of their employment. Drivers who did not comply with the evaluation or with PAP after diagnosis were removed from driving commercial vehicles by the company or did not pursue further employment.

Results

A total of 975 drivers were enrolled. Among screened drivers, 35.5% were cleared without a sleep study, 15.0% were cleared following a sleep study (apnoea-hypopnoea index (AHI) <5 events·h-1), 22.1% had mild OSA (AHI 5-15) and 27.4% had moderate-severe OSA (AHI ≥15). Those with moderate-severe OSA were more obese (body mass index 36.2±6.3 kg·m-2) and had more comorbidities. Of 269 drivers starting PAP, 160 (59.5%) maintained participation in a care management programme, 80 (29.7%) resigned or were terminated, 23 (8.6%) were cleared to discontinue PAP and six (2.2%) were complex cases requiring transfer of care. Illustrating effectiveness, those that maintained participation had excellent PAP adherence (5.27±1.61 h·night-1; 88.5±12.9% days used; 79.7±17.7% days used ≥4 h).

Interpretation

Remote assessment of OSA and PAP management in commercial drivers is feasible and effective. This approach has wide-ranging applications, particularly in populations and areas with a lack of sleep medicine providers.

Feasibility and usability of three consecutive nights with self-applied, home polysomnography

In-laboratory polysomnography, the gold-standard for diagnosing sleep disorders, is resource-demanding and not conducive to multiple night evaluations. Ambulatory polysomnography, especially when self-applied, could be a viable alternative. This study aimed to assess the feasibility and reliability of self-applied polysomnography over three consecutive nights in untrained participants, assessing: technical success rate; comparing sleep diagnostic variables from single and multiple nights; and evaluating participants' subjective experience. Data were collected from 78 participants (55.1% females) invited to test a self-applicable polysomnography device for three consecutive nights at home. The technical success rate for valid sleep recordings was 82.5% out of 234 planned study nights, with 87.2% of participants obtaining at least two valid nights. Misclassification of obstructive sleep apnea severity was higher in participants with mild OSA (21.4%) compared with those with moderate-to-severe obstructive sleep apnea or no obstructive sleep apnea. Sleep efficiency and wake after sleep onset showed improvement from Night 1 to Night 3 (p < 0.001), and the mean polysomnography set-up time decreased significantly over this period. Participants reported moderate-to-high satisfaction with the device (System Usability Scale score 71.2 ± 12.4). The findings suggest that self-applied polysomnography is a feasible diagnostic method for untrained individuals at risk for sleep disorders, and that multiple night assessments can improve diagnostic precision for mild obstructive sleep apnea cases.

Intermittent hypoxia induces Th17/Treg imbalance in a murine model of obstructive sleep apnea

Obstructive sleep apnea (OSA) is characterized by cyclic normoxic and hypoxic conditions (intermittent hypoxia, IH) induced by the repeated closure of the upper-airway respiratory tract. As a pathomechanism of OSA, IH results in various comorbidities via chronic inflammation and related pathways. However, the role of other inflammatory cells, such as lymphocytes, has not been well-explored. This study aimed to examine the effects of IH on the distribution and balance of T cell subsets and other related cytokines, and mechanisms in the immune system. We modified OSA mouse model (male C57BL/6N male) using our customized chamber that controls specific sleep and oxygenic cycles. To induce hypoxia, the IH group was repeatedly exposed to 5% O2 and 21% O2 lasting for 120 s each for 7 h daily for 4 weeks. Mice were then subjected to a recovery period of 4 weeks, in which IH stimulation was ceased. T cells and related cytokines were analyzed using flow cytometry and immunohistochemistry. Compared with the control group, the IH group had significantly lower levels of CD4+CD25+Foxp3+ regulatory T cells but higher levels of Th 17, IL-4, HIF-1, and inflammatory cytokines. After the recovery period, these altered changes in the immune cells were recovered, and we found no significant difference in their levels between the control and recovery groups. This study revealed that the Th17/Treg ratio is increased by intermittent hypoxia, and this imbalance can explain immune-related diseases, including recently reported allergies, autoimmune, and even cancer diseases, arising from OSA.

The Value of Implementing a Digital Approach in the Obstructive Sleep Apnoea Patient Pathway: A Spanish Example

Introduction

Continuous positive airway pressure (CPAP) is the gold standard therapy for obstructive sleep apnoea (OSA). However, non-adherence is common and costly. The COVID-19 pandemic required the use of novel solutions to ensure service provision and quality of care. This retrospective analysis determined the impact and value of a digital versus standard pathway for the management of OSA in Spain.

Methods

A time-driven activity-based costing approach was applied to OSA management over 1 year using a standard or digital pathway. The standard pathway included face-to-face appointments at the time of diagnosis, then after 1-3 months and every 6 months thereafter. The digital pathway had fewer face-to-face appointments and utilised telemonitoring. A cost analysis was performed to determine the per-patient cost per healthcare professional (HCP) for a digital pathway for therapy implementation and follow-up compared with the standard pathway.

Results

Compared with the standard pathway, the digital pathway decreased the waiting list time from 18 to 2 months, the overall pathway time from 12 to 6 months, HCP cost per patient from €95 to €85, and number of hospital appointments per patient from 6 to 3.1. Furthermore, CPAP device usage improved from 5.7 to 6.3 h/night and the proportion of individuals defined as adherent increased from 79% to 91%.

Conclusions

Implementation of digital processes using available technology reduced HCP time and costs, and improved adherence to CPAP in people with OSA. Greater utilisation of a digital pathway could improve access to therapy, allow personalised patient management, and facilitate better clinical outcomes.

A nationwide study on the prevalence and contributing factors of obstructive sleep apnea in Iran

Reliable obstructive sleep apnea (OSA) prevalence information in Iran is lacking due to inconsistent local study results. To estimate OSA prevalence and identify clinical phenotypes, we conducted a nationally representative study using multi-stage random cluster sampling. We recruited 3198 individuals and extrapolated the results to the entire Iranian population using complex sample survey analyses. We identified 3 clinical phenotypes as "sleepy," "insomnia," and "restless legs syndrome (RLS)." The prevalence of OSA was 28.7% (95%CI: 26.8-30.6). The prevalence of "sleepy," "insomnia," and "RLS" phenotypes were 82.3%, 77.8%, and 36.5% in women, and 64.8%, 67.5%, and 17.9% in men, respectively. "Sleepy" and "insomnia" phenotypes overlapped the most. Age (OR: 1.9), male sex (OR: 3.8), BMI (OR: 1.13), neck circumference (OR: 1.3), RLS (OR: 2.0), and insomnia (OR: 2.3) were significant OSA predictors (p-values: 0.001). In men, "sleepy" phenotype was associated with youth and unmarried status but not in women. The "insomnia" phenotype was associated with shorter sleep duration in women; cardiovascular diseases (CVD), urban residency, and shorter sleep duration in men. "RLS" phenotype was associated with shorter sleep duration and CVD in women and older age, lower educational level, CVD, and hypertension in men. The findings point to the need for funding of OSA screening in Iran, for a different assessment of men and women, and for future sleep research to consider overlapping phenotypes.

Clinical Practice Guideline: Clinical Efficacy of Nasal Surgery in the Treatment of Obstructive Sleep Apnea

Obstructive sleep apnea (OSA) is a common disorder characterized by upper airway obstruction during sleep. To reduce the morbidity of OSA, sleep specialists have explored various methods of managing the condition, including manifold positive airway pressure (PAP) techniques and surgical procedures. Nasal obstruction can cause significant discomfort during sleep, and it is likely that improving nasal obstruction would enhance the quality of life and PAP compliance of OSA patients. Many reliable studies have offered evidence to support this assumption. However, few comprehensive guidelines for managing OSA through nasal surgery encompass all this evidence. In order to address this gap, the Korean Society of Otorhinolaryngology-Head and Neck Surgery (KORL-HNS) and the Korean Society of Sleep and Breathing designated a guideline development group (GDG) to develop recommendations for nasal surgery in OSA patients. Several databases, including OVID Medline, Embase, the Cochrane Library, and KoreaMed, were searched to identify all relevant papers using a predefined search strategy. The types of nasal surgery included septoplasty, turbinate surgery, nasal valve surgery, septorhinoplasty, and endoscopic sinus surgery. When insufficient evidence was found, the GDG sought expert opinions and attempted to fill the evidence gap. Evidence-based recommendations for practice were ranked according to the American College of Physicians' grading system. The GDG developed 10 key action statements with supporting text to support them. Three statements are ranked as strong recommendations, three are only recommendations, and four can be considered options. The GDG hopes that this clinical practice guideline will help physicians make optimal decisions when caring for OSA patients. Conversely, the statements in this guideline are not intended to limit or restrict physicians' care based on their experience and assessment of individual patients.

International Consensus Statement on Obstructive Sleep Apnea

BACKGROUND

Evaluation and interpretation of the literature on obstructive sleep apnea (OSA) allows for consolidation and determination of the key factors important for clinical management of the adult OSA patient. Toward this goal, an international collaborative of multidisciplinary experts in sleep apnea evaluation and treatment have produced the International Consensus statement on Obstructive Sleep Apnea (ICS:OSA).

METHODS

Using previously defined methodology, focal topics in OSA were assigned as literature review (LR), evidence-based review (EBR), or evidence-based review with recommendations (EBR-R) formats. Each topic incorporated the available and relevant evidence which was summarized and graded on study quality. Each topic and section underwent iterative review and the ICS:OSA was created and reviewed by all authors for consensus.

RESULTS

The ICS:OSA addresses OSA syndrome definitions, pathophysiology, epidemiology, risk factors for disease, screening methods, diagnostic testing types, multiple treatment modalities, and effects of OSA treatment on multiple OSA-associated comorbidities. Specific focus on outcomes with positive airway pressure (PAP) and surgical treatments were evaluated.

CONCLUSION

This review of the literature consolidates the available knowledge and identifies the limitations of the current evidence on OSA. This effort aims to create a resource for OSA evidence-based practice and identify future research needs. Knowledge gaps and research opportunities include improving the metrics of OSA disease, determining the optimal OSA screening paradigms, developing strategies for PAP adherence and longitudinal care, enhancing selection of PAP alternatives and surgery, understanding health risk outcomes, and translating evidence into individualized approaches to therapy.

Metabolomic approach for obstructive sleep apnea in adults: a systematic review

Obstructive Sleep Apnea (OSA) corresponds to episodes of complete or partial upper airway obstruction during sleep. The gold standard for diagnosing OSA is polysomnography; however, metabolomics is an innovative and highly sensitive method that seeks to identify and quantify small molecules in biological systems. Identify the metabolites most frequently associated with obstructive sleep apnea in adults. The search for articles was conducted between October 2020 and August 2021, in electronic databases, such as MEDLINE/PubMed, Scielo, Embase, and Cochrane, through the combination of descriptors: obstructive sleep apnea, metabolomic, adult. This systematic review included all cross-sectional studies published, including human patients aged 18 years or older, of both genders who underwent type I or II polysomnography and metabolomics study. The search strategy selected 3697 surveys, and 4 of them were selected to be a part of this systematic review. Based on the analyzed surveys, it was found that all of them were able to diagnose OSA, reaching a sensitivity of 75-97%, and specificity that ranged from 72 to 100%; besides differentiating patients with OSA (severe, moderate, and mild) from simple snorers with a mean sensitivity of 77.2% and specificity of 66.25%. These findings suggest that, in addition to being used as a screening and diagnostic strategy for OSA, metabolomics has the potential to be used for severity stratification and to monitor the disease's progression.

Association Between Positive Airway Pressure Adherence and Health Care Costs Among Individuals With OSA

BACKGROUND

The impact of positive airway pressure (PAP) therapy for OSA on health care costs is uncertain.

RESEARCH QUESTION

Are 3-year health care costs associated with PAP adherence in participants from the Tele-OSA clinical trial?

STUDY DESIGN AND METHODS

Participants with OSA and prescribed PAP in the Tele-OSA study were stratified into three PAP adherence groups based on usage patterns over 3 years: (1) high (consistently ≥ 4 h/night), (2) moderate (2-3.9 h/night or inconsistently ≥ 4 h/night), and (3) low (< 2 h/night). Using data from 3 months of the Tele-OSA trial and 33 months of posttrial follow up, average health care costs (2020 US dollars) in 6-month intervals were derived from electronic health records and analyzed using multivariable generalized linear models.

RESULTS

Of 543 participants, 25% were categorized as having high adherence, 22% were categorized as having moderate adherence, and 52% were categorized as having low adherence to PAP therapy. Average PAP use mean ± SD was 6.5 ± 1.0 h, 3.7 ± 1.2 h, and 0.5 ± 0.5 h for the high, moderate, and low adherence groups, respectively. The high adherence group had the lowest average covariate-adjusted 6-month health care costs ± SE ($3,207 ± $251) compared with the moderate ($3,638 ± $363) and low ($4,040 ± $304) adherence groups. Significant cost differences were observed between the high and low adherence groups ($832; 95% CI, $127 to $1,538); differences between moderate and low adherence were nonsignificant ($401; 95% CI, -$441 to $1,243).

INTERPRETATION

In participants with OSA, better PAP adherence was associated with significantly lower health care costs over 3 years. Findings support the importance of strategies to enhance long-term PAP adherence.

Autoantibodies of inflammatory cytokines as serum biomarkers in OSA patients

As many as 90% of patients with obstructive sleep apnea (OSA) may be undiagnosed. It is necessary to explore the potential value of autoantibodies against CRP, IL-6, IL-8 and TNF-α in the diagnosis of OSA. ELISA was performed to detect the level of autoantibodies against CRP, IL-6, IL-8 and TNF-α in sera from 264 OSA patients and 231 normal controls (NCs). The expression level of autoantibodies against CRP, IL-6 and IL-8 in OSA were significantly higher than that in NC while the level of anti-TNF-α was lower in OSA than that in NC. The per SD increment of anti-CRP, anti-IL-6 and anti-IL-8 autoantibodies were significantly associated with a 430%, 100% and 31% higher risk for OSA, respectively. The AUC of anti-CRP was 0.808 (95% CI: 0.771-0.845) when comparing OSA with NC, while the AUC increased to 0.876 (95% CI: 0.846-0.906) combining four autoantibodies. For discrimination of severe OSA versus NC and non-severe OSA versus NC, the AUC for four autoantibodies combination was 0.885 (95% CI: 0.851-0.918) and 0.876 (95% CI: 0.842-0.913). This study revealed the association between autoantibodies against inflammatory factors and OSA, and the combination of autoantibodies against CRP, IL-6, IL-8 and TNF-α may function as novel biomarker for monitoring the presence of OSA.

OMS residents’ obstructive sleep apnea‐related education, knowledge, and professional behavior: A national survey

OBJECTIVES

Oral and maxillofacial surgeons (OMS) treat adult and pediatric patients with obstructive sleep apnea (OSA). Objective 1 assessed sleep apnea-related education, knowledge, and professional behavior of OMS residents in the United States. Objective 2 was to compare the responses of junior versus senior residents and residents in single- versus dual-degree programs.

METHODS

OMS residents in the United States received a recruitment email with a link to an anonymous online survey; 81 residents responded. The survey included 20 questions to assess respondents' OSA-related education, knowledge, attitudes, and professional behavior.

RESULTS

Respondents generally agreed that they had received OSA-related didactic-based education (5-point scale with "5" = agree strongly: mean = 3.62) and clinical training (mean = 3.75). Clinical and classroom educational gaps were identified in relation to treatment with oral appliances and hypoglossal nerve stimulation. The residents scored on average 10.38 out of 18 (58%) possible correct answer points for the knowledge questions. Findings about pediatric OSA suggest that only 43.8% of residents understand diagnostic criteria for pediatric OSA, with only 26.6% screening pediatric patients for OSA. A case analysis showed that only 1.5% of residents correctly identified an apnea-hypopnea index of 17 as moderate sleep apnea.

CONCLUSION(S)

This survey found knowledge gaps in several areas that can be improved upon. It identifies deficiency in objective knowledge about OSA among OMS residents and a specific lack of clinical training and confidence with hypoglossal nerve stimulation and management of pediatric patients with OSA. Junior and senior residents and single- and dual-degree residents showed no statistically significant differences in any category except senior residents in regard to surgical management of OSA, particularly with maxillomandibular advancement.

The association between sleep disorders on employment and income among adults in the United States

STUDY OBJECTIVES

To examine the association between sleep disorders, employment status, and income among US adults aged 18-64 years.

METHODS

The 2018-2019 Medical Expenditure Panel Survey medical conditions file was queried for adults aged 18-64 years with a diagnosis of a sleep disorder (International Classification of Diseases, 10th Revision, code G47.x) and linked to the household dataset. Comparisons in rates of wage, supplemental, and social security income as well as mean wage income were made between those with and without sleep disorders. Multivariate analyses, adjusting for demographics and comorbidities, were conducted.

RESULTS

A sleep disorder was diagnosed in 4.4% ± 0.2% of the study population (approximately 8.8 ± 0.4 million adults aged 18-64 years in the United States; mean age 46.9 years, 55.8% female). Adults with sleep disorders were less likely to have wage income from employment (adjusted odds ratio 0.5, 95% confidence interval 0.4-0.6, P < .001) and more likely to have Supplemental Security (1.8, 1.4-2.4, P < .001) and Social Security income (2.0, 1.6-2.4, P < .001) compared with those without sleep disorders. Among wage-earning adults, those with sleep disorders had $2,496 less mean annual wage income compared with those without a sleep disorder ($20,445 vs $22,941, P = .007), adjusting for demographics and comorbidities.

CONCLUSIONS

There are significantly higher indirect costs associated with sleep disorders. This study specifically demonstrates lower employment rates, lower wages, and higher welfare income utilization among those with sleep disorders despite using a very conservative estimate of sleep disorder prevalence.

CITATION

Huyett P, Bhattacharyya N. The association between sleep disorders, employment, and income among adults in the United States. J Clin Sleep Med. 2022;18(8):1967-1972.

The association between obstructive sleep apnea risk and cognitive disorders: a population-based study

STUDY OBJECTIVES

To examine the association between OSA risk and cognitive disorders among US adults.

METHODS

Data from the 2016 wave of the Health and Retirement Study (HRS) were utilized. Probable OSA cases were identified with survey items that resembled critical elements of a clinically validated OSA screen (STOP-Bang questionnaire). Weighted prevalence of cognitive impairment not dementia (CIND) and dementia among individuals with and without probable OSA were assessed. Cross-sectional analyses of associations between OSA risk and cognitive outcomes, along with effect modification by race and ethnicity, were estimated using imputed data.

RESULTS

Of the 20,910 HRS participants, 60% had probable OSA. CIND and dementia were more common among adults with probable OSA as compared to those without (12.7% vs. 8.0% for CIND; 3.2% vs 2.0% for dementia). Probable OSA was associated with CIND (OR=1.22, 1.08-1.37) and dementia (OR=1.27, 1.04-1.54). Race/ethnicity significantly modified the association between probable OSA and CIND, with a higher risk for CIND in Whites (OR=1.35, 1.17-1.57) as compared to non-Whites (OR=0.98, 0.81-1.19).

CONCLUSIONS

CIND and dementia are more common among older adults who are at high risk for OSA, as compared to low-risk individuals. These data highlight the importance of consideration of OSA risk in large-scale studies of OSA and cognitive disorders.

Ensemble-learning regression to estimate sleep apnea severity using at-home oximetry in adults

Overnight pulse oximetry has shown usefulness to simplify obstructive sleep apnea (OSA) diagnosis when combined with machine-learning approaches. However, the development and evaluation of a single model with ability to reach high diagnostic performance in both community-based non-referral and clinical referral cohorts are still pending. Since ensemble-learning algorithms are known for their generalization ability, we propose a least-squares boosting (LSBoost) model aimed at estimating the apnea-hypopnea index (AHI), as the correlate clinical measure of disease severity. A thorough characterization of 8,762 nocturnal blood-oxygen saturation signals (SpO2) obtained at home was conducted to extract the oximetric information subsequently used in the training, validation, and test stages. The estimated AHI derived from our model achieved high diagnostic ability in both referral and non-referral cohorts reaching intra-class correlation coefficients within 0.889-0.924, and Cohen's κ within 0.478-0.663 when considering the four OSA severity categories. These resulted in accuracies ranging 87.2%-96.6%, 81.1%-87.6%, and 91.6%-94.6% when assessing the three typical AHI severity thresholds, 5 events/hour (e/h), 15 e/h, and 30 e/h, respectively. Our model also revealed the importance of the SpO2 predictors, thereby minimizing the 'black box' perception traditionally attributed to the machine-learning approaches. Furthermore, a decision curve analysis emphasized the clinical usefulness of our proposal. Therefore, we conclude that the LSBoost-based model can foster development of clinically applicable and cost saving protocols for detection of patients attending primary care services, or to avoid full polysomnography in specialized sleep facilities, thus demonstrating the diagnostic usefulness of SpO2 signals obtained at home.

Night to night variability of pulse oximetry features in children at home and at the hospital

Objective. Investigation of the night-to-night (NtN) variability of pulse oximetry features in children with suspicion of Sleep Apnea.Approach. Following ethics approval and informed consent, 75 children referred to British Columbia Children's Hospital for overnight PSG were recorded on three consecutive nights, including one at the hospital simultaneously with polysomnography and 2 nights at home. During all three nights, a smartphone-based pulse oximeter sensor was used to record overnight pulse oximetry (SpO2 and photoplethysmogram). Features characterizing SpO2 dynamics and heart rate were derived. The NtN variability of these features over the three different nights was investigated using linear mixed models.Main results. Overall most pulse oximetry features (e.g. the oxygen desaturation index) showed no NtN variability. One of the exceptions is for the signal quality, which was significantly lower during at home measurements compared to measurements in the hospital.Significance. At home pulse oximetry screening shows an increasing predictive value to investigate obstructive sleep apnea (OSA) severity. Hospital recordings affect subjects normal sleep and OSA severity and recordings may vary between nights at home. Before establishing the role of home monitoring as a diagnostic test for OSA, we must first determine their NtN variability. Most pulse oximetry features showed no significant NtN variability and could therefore be used in future at-home testing to create a reliable and consistent OSA screening tool. A single night recording at home should be able to characterize pulse oximetry features in children.

Circulating levels of ghrelin, galanin, and orexin-A orexigenic neuropeptides in obstructive sleep apnea syndrome

PURPOSE

The orexigenic peptides, ghrelin, galanin, and orexin-A, have an important role in food intake and energy homeostasis and regulate the higher brain functions including the sleep-wake state. Although the interactions of these neuropeptides affect neuroendocrine systems resulting in obesity, a major risk factor for obstructive sleep apnea syndrome (OSAS), the mechanism has not been fully elucidated. The objective of this study was to evaluate the association of serum ghrelin, galanin, and orexin-A levels with OSAS.

METHODS

In this cross-sectional study, patients who underwent one-night polysomnography and conformed to the inclusion criteria were asked to participate. A blood sample was obtained from all participants on the morning of the sleep test to evaluate the serum levels of ghrelin, galanin, and orexin-A using the enzyme-linked immunosorbent assay (ELISA) method. Demographic characteristics, polysomnography data, and serum levels of the participants were recorded and analyzed. Comparison between the OSAS groups was performed by independent sample t-test, Mann-Whitney U test, and Kruskal-Wallis test with post hoc K-W test using SPSS 20.0.

RESULTS

Of 272 patients, those in the OSAS group (n=210) were older than patients in the non-OSAS group (n=62), p < 0.003, and had increased BMI, p < 0.006. Patients with, serum ghrelin, galanin, and orexin-A levels were significantly elevated in patients with OSAS (635.9 pg/mL vs. 420.7 pg/mL, 91.0 pg/mL vs. 60.0 pg/mL, 600.3 pg/mL vs. 485.6 pg/mL, respectively) and found to be higher in patients with severe OSAS than mild and moderate cases (p < 0.01). In multinomial logistic regression to predict the OSAS severity, levels of serum ghrelin (OR = 1.016 [1.010-1.021]; p < 0.001), galanin (OR = 1.050 [1.020-1.081]; p < 0.001), and orexin-A (OR = 1.021 [1.012-1.030]; p < 0.001) were significantly associated only with a moderate level of OSAS.

CONCLUSION

The orexigenic neuropeptides were found to be an independent determinant of the presence of OSAS and correlate with the severity of OSAS. Increased levels of ghrelin, galanin, and orexin-A were associated with the presence of moderate OSAS.

Incremental health care utilization and expenditures for sleep disorders in the United States

STUDY OBJECTIVES

To determine the incremental increases in health care utilization and expenditures associated with sleep disorders.

METHODS

Adults with a diagnosis of a sleep disorder (International Classification of Diseases, 10th Revision, code G47.x) within the medical conditions file of the 2018 Medical Expenditure Panel Survey medical conditions file were identified. This dataset was then linked to the consolidated expenditures file and comparisons in health care utilization and expenditures were made between those with and without sleep disorders. Multivariate analyses, adjusted for demographics and comorbidities, were conducted for these comparisons.

RESULTS

Overall, 5.6% ± 0.2% of the study population had been diagnosed with a sleep disorder, representing approximately 13.6 ± 0.6 million adults in the United States. Those with sleep disorders were more likely to be non-Hispanic, White, and female, with a higher proportion with public insurance and higher Charlson Comorbidity Scores. Adults with sleep disorders were found to have increased utilization of office visits (16.3 ± 0.8 vs 8.7 ± 0.3, P < .001), emergency room visits (0.52 ± 0.03 vs 0.37 ± 0.02, P < .001), and prescriptions (39.7 ± 1.2 vs 21.9 ± 0.4, P < .001) vs those without sleep disorders. The additional incremental health care expenses for those with sleep disorders were increased in all examined measures: total health care expense ($6,975 ± $800, P < .001), total office-based expenditures ($1,694 ± $277, P < .001), total prescription expenditures ($2,574 ± $364, P < .001), and total self-expenditures for prescriptions ($195 ± $32, P < .001).

CONCLUSIONS

Sleep disorders are associated with significantly higher rates of health care utilization and expenditures. By using the conservative prevalence estimate found in this study, the overall incremental health care costs of sleep disorders in the United States represents approximately $94.9 billion.

CITATION

Huyett P, Bhattacharyya N. Incremental health care utilization and expenditures for sleep disorders in the United States. J Clin Sleep Med. 2021;17(10):1981-1986.

Telemedicine Strategy to Rescue CPAP Therapy in Sleep Apnea Patients with Low Treatment Adherence: A Pilot Study

Patients with sleep apnea are usually treated with continuous positive airway pressure (CPAP). This therapy is very effective if the patient′s adherence is satisfactory. However, although CPAP adherence is usually acceptable during the first months of therapy, it progressively decreases, with a considerable number of patients accepting average treatment duration below the effectiveness threshold (4 h/night). Herein, our aim was to describe and evaluate a novel telemedicine strategy for rescuing CPAP treatment in patients with low adherence after several months/years of treatment. This two-week intervention includes (1) patient support using a smartphone application, phone and voice recorder messages to be answered by a nurse, and (2) daily transmission and analysis of signals from the CPAP device and potential variation of nasal pressure if required. On average, at the end of the intervention, median CPAP adherence considerably increased by 2.17 h/night (from 3.07 to 5.24 h/night). Interestingly, the procedure was able to markedly rescue CPAP adherence: the number of patients with poor adherence (<4 h/night) was considerably reduced from 38 to 7. After one month, adherence improvement was maintained (median 5.09 h/night), and only 13 patients had poor adherence (<4 h/night). This telemedicine intervention (103€ per included patient) is a cost-effective tool for substantially increasing the number of patients with CPAP adherence above the minimum threshold for achieving positive therapeutic effects.

The public health burden of obstructive sleep apnea

Obstructive sleep apnea (OSA) is the most common respiratory disorder of sleep. The vast majority (>80%) of adults with moderate to severe OSA remain undiagnosed. The economic costs associated with OSA are substantial for both the individual and society as a whole; expenses are likely to be underestimated given that the disease remains undiagnosed in such a large percentage of individuals. The economic burden of motor vehicle collisions related to OSA alone is significant; it is estimated that 810,000 collisions and 1400 fatalities from car crashes in the United States were attributable to sleep apnea in 2000. The many health consequences of OSA include daytime sleepiness, reduced quality of life, decreased learning skills, and importantly, neurocognitive impairments that include impaired episodic memory, executive function, attention and visuospatial cognitive functions. Untreated OSA leads to numerous medical problems such as cardiovascular diseases that can potentially increase healthcare utilization. Untreated patients with sleep apnea consume a disproportionate amount of healthcare resources, expenditures that decrease after treatment. The gold-standard management of OSA remains treatment with CPAP (Continuous Positive Airway Pressure), which is effective in eliminating sleep fragmentation and preserving nocturnal oxygenation, thereby improving daytime sleepiness and quality of life. However, its impacts in reversing neurocognitive function are still uncertain. A significant impediment to CPAP effectiveness is low adherence rates (ranges from 50% to 75%). It is commonly accepted that CPAP improves excessive drowsiness; hence meliorates attention, and accumulating data suggest that CPAP improves a variety of other outcomes such as the risk of motor vehicle crashes.

Enhancing Obstructive Sleep Apnea Diagnosis With Screening Through Disease Phenotypes: Algorithm Development and Validation

BACKGROUND

The American Academy of Sleep Medicine guidelines suggest that clinical prediction algorithms can be used in patients with obstructive sleep apnea (OSA) without replacing polysomnography, which is the gold standard.

OBJECTIVE

This study aims to develop a clinical decision support system for OSA diagnosis according to its standard definition (apnea-hypopnea index plus symptoms), identifying individuals with high pretest probability based on risk and diagnostic factors.

METHODS

A total of 47 predictive variables were extracted from a cohort of patients who underwent polysomnography. A total of 14 variables that were univariately significant were then used to compute the distance between patients with OSA, defining a hierarchical clustering structure from which patient phenotypes were derived and described. Affinity from individuals at risk of OSA phenotypes was later computed, and cluster membership was used as an additional predictor in a Bayesian network classifier (model B).

RESULTS

A total of 318 patients at risk were included, of whom 207 (65.1%) individuals were diagnosed with OSA (111, 53.6% with mild; 50, 24.2% with moderate; and 46, 22.2% with severe). On the basis of predictive variables, 3 phenotypes were defined (74/207, 35.7% low; 104/207, 50.2% medium; and 29/207, 14.1% high), with an increasing prevalence of symptoms and comorbidities, the latter describing older and obese patients, and a substantial increase in some comorbidities, suggesting their beneficial use as combined predictors (median apnea-hypopnea indices of 10, 14, and 31, respectively). Cross-validation results demonstrated that the inclusion of OSA phenotypes as an adjusting predictor in a Bayesian classifier improved screening specificity (26%, 95% CI 24-29, to 38%, 95% CI 35-40) while maintaining a high sensitivity (93%, 95% CI 91-95), with model B doubling the diagnostic model effectiveness (diagnostic odds ratio of 8.14).

CONCLUSIONS

Defined OSA phenotypes are a sensitive tool that enhances our understanding of the disease and allows the derivation of a predictive algorithm that can clearly outperform symptom-based guideline recommendations as a rule-out approach for screening.

Employer-mandated obstructive sleep apnea treatment and healthcare cost savings among truckers

OBJECTIVE

To evaluate the effect of an employer-mandated obstructive sleep apnea (OSA) diagnosis and treatment program on non-OSA-program trucker medical insurance claim costs.

METHODS

Retrospective cohort analysis; cohorts constructed by matching (randomly, with replacement) Screen-positive Controls (drivers with insurance screened as likely to have OSA, but not yet diagnosed) with Diagnosed drivers (n = 1,516; cases = 1,224, OSA Negatives = 292), on two factors affecting exposure to medical claims: experience level at hire and weeks of job tenure at the Diagnosed driver's polysomnogram (PSG) date (the "matching date"). All cases received auto-adjusting positive airway pressure (APAP) treatment and were grouped by objective treatment adherence data: any "Positive Adherence" (n = 932) versus "No Adherence" (n = 292). Bootstrap resampling produced a difference-in-differences estimate of aggregate non-OSA-program medical insurance claim cost savings for 100 Diagnosed drivers as compared to 100 Screen-positive Controls before and after the PSG/matching date, over an 18-month period. A two-part multivariate statistical model was used to set exposures and demographics/anthropometrics equal across sub-groups, and to generate a difference-in-differences comparison across periods that identified the effect of OSA treatment on per-member per-month (PMPM) costs of an individual driver, separately from cost differences associated with adherence choice.

RESULTS

Eighteen-month non-OSA-program medical claim costs savings from diagnosing (and treating as required) 100 Screen-positive Controls: $153,042 (95% CI: -$5,352, $330,525). Model-estimated effect of treatment on those adhering to APAP: -$441 PMPM (95% CI: -$861, -$21).

CONCLUSIONS

Results suggest a carrier-based mandatory OSA program generates substantial savings in non-OSA-program medical insurance claim costs.

Usefulness of sleep events detection using a wrist worn peripheral arterial tone signal device (WatchPAT™) in a population at low risk of obstructive sleep apnea

Due to the high prevalence of obstructive sleep apnea (OSA), it is recommended to use in-laboratory polysomnography (PSG) or a home sleep apnea test (HSAT) in uncomplicated adult subjects at high risk of OSA. The aims of the present study were to compare a HSAT device, a wrist worn peripheral arterial tone signal device (WatchPAT™-200 [WP]) with PSG and respiratory polygraphy (RP) in a low-risk population of OSA. A total of 47 adult subjects at low risk of OSA were simultaneously examined with the three different approaches in a single night. The sleep studies were scored independently and in a blinded fashion, then the results and the parameters (Respiratory Disturbance Index, apnea-hypopnea index [AHI] and oxygen desaturation index of 3%) were compared with several statistical analyses. The agreement between the sleep tools and correlation for the assessed parameters were analysed and compared with Bland and Altman plots and Pearson's coefficient (WP versus PSG, r = 0.86). For the severity of OSA ranked according to PSG, the Cohen's k was 0.60 and 0.82 for WP and RP, respectively. Specificity was higher for RP compared to WP for identifying the presence of OSA (AHIPSG cut-off ≥5 events/hr: 0.85 versus 0.73), while was quite similar in identifying patients who were more likely to be treated (AHIPSG cut-off ≥15 events/hr: 0.94 versus 0.96). Assessing the costs and the simplicity of the examination, the results of our present study demonstrate the usefulness of WP compared to PSG, especially in screening and follow-up for the ability to exclude subjects from treatment with continuous positive airway pressure (AHI <15 events/hr) in a population with a low pre-test risk of moderate-to-severe OSA.

Changes in headache characteristics with oral appliance treatment for obstructive sleep apnea

Changes in headache characteristics in obstructive sleep apnea (OSA) patients following oral appliance treatment was investigated for the first time. Thirteen OSA patients with headaches treated with a mandibular advancement device were investigated. Level I polysomnography and Migraine Disability Assessment Questionnaire were completed before and after treatment. Various headache characteristics and concomitant conditions were analyzed. The patient was considered a headache responder when ≥ 30% reduction in headache frequency following treatment. Differences in headache and polysomnographic parameters were compared between headache responder groups. Eight patients (62%) were headache responders. Eleven patients (85%) before and 7 (54%) after treatment reported morning headaches. Significantly more patients had bilateral headache in the responder group before treatment (P = 0.035). The severest headache intensity (P = 0.018) at baseline showed a significant decrease in the headache responder group after treatment. The time spent in N2 (r = - 0.663, P = 0.014), REM sleep (r = 0.704, P = 0.007) and mean oxygen saturation (r = 0.566, P = 0.044) showed a significant correlation with post-treatment average headache intensity. Pre-treatment lower PLM index (r = - 0.632, P = 0.027) and higher mean oxygen saturation levels (r = 0.592, P = 0.043) were significantly correlated with higher post-treatment severest headache intensity. Treatment with an oral appliance is beneficial for many OSA patients with headaches. It should be considered as an alternative treatment in headache patients with mild to moderate OSA.

Determining the prevalence of symptoms and risk of obstructive sleep apnoea among old Saudis

Objectives

This study aimed to determine the prevalence of symptoms and risk of obstructive sleep apnoea (OSA) and to identify the risk factors associated with OSA among old Saudis.

Methods

In this population-based survey, we administered the Saudi National Survey for Elderly Health to old Saudis between 2006 and 2007. Symptoms of OSA and its associated risk factors were determined using the Berlin questionnaire. A multivariable logistic regression analysis was used to determine key factors associated with the risk of OSA.

Results

Out of 2946 participants, 1544 (52.4%) were at high risk of OSA, with women having a higher risk than men (60.8% vs. 44.2%, respectively; p-value <0.001). Obesity was higher among women than men (40.5% vs. 24.8%, respectively; p-value <0.001). Almost 56% of the participants reported snoring as a risk factor, but there was no statistical difference between women and men (57.3% vs. 53.5%, respectively; p-value = 0.317). The factors identified as independent predictors of a high risk of OSA were the female gender (OR 1.732, 95% CI [1.375–2.182]), living in rural areas (OR 1.384, 95% CI [1.094–1.750]), severe cognitive impairment (OR 2.709, 95% CI [1.350–5.436]), depression (OR: 1.432 95%CI [1.147–1.789]), and antidepressants usage (OR 2.959, 95% CI [1.402–6.244]).

Conclusion

This study reported a 52.4% prevalence of a high risk of OSA. Women were more likely to be at high risk of OSA than men. In addition to the female gender, depression, antidepressant usage, severe cognitive impairment, and living in rural areas were main predictors of OSA.

Salivary biomarkers associated with obstructive sleep apnea: a systematic review

Introduction: This study aimed to define and characterize current literature describing salivary biomarker changes with the goal of improving diagnosis and treatment outcomes for sleep apnea.Area Covered: A search of six databases yielded 401 peer-reviewed articles published through October 2019 corresponded to 221 unique references following deduplication. Twenty studies were selected. The sample size ranged from 17 to 99. The samples were mostly whole saliva and selected glandular areas.Expert Opinion: Most targeted studies focused on the level of salivary cortisol and ɑ-amylase. One study used RNA transcriptome analysis of 96 genes. Only two explored novel targets using mass spectrometry. ɑ-amylase, myeloperoxidase, and IL-6 were among those biomarkers found associated with OSA. Cytokeratin, CystatinB, calgranulin A, and alpha-2-HS-glycoprotein are upregulated in OSA patients based on non-targeting mass spectrometry. Salivary cortisol and ɑ-amylase and others appeared to be associated with severity of OSA and OSA treatment. There were inconsistencies in saliva collection and processing protocols. More studies are needed in exploring novel biomarkers to examine if these biomarkers are capable of diagnosing and monitoring OSA through proteomics or transcriptomics. Salivary biomarkers have a potential to be a noninvasive measure for the disease diagnosis and treatment outcome monitoring for sleep apnea.

Evaluation of Obstructive Sleep Apnea in Female Patients in Primary Care: Time for Improvement?

Obstructive sleep apnea (OSA) has historically been regarded as a male disease. However, there are a number of significant gender-related differences in the symptoms, diagnosis, and consequences of OSA, which seems to be more severe in male than in female patients, although this sex difference decreases with increasing age. Female patients with OSA tend to present nonspecific symptoms, such as insomnia, depressive symptoms, fatigue, morning headache, and nightmares, often resulting in underdiagnosis and undertreatment compared to male patients. Understanding these differences in women is essential for early identification and referral of patients for diagnosis and treatment of OSA.

Adherence to prescribed overnight sleep study in patients suspected of sleep apnea: problem size and influential factors

PURPOSE

Despite the serious consequences of sleep apnea, some patients do not follow their physicians' advice to undergo a sleep study. The present study aimed to determine the rate of adherence and influencing factors in conducting a polysomnography test in patients suspected of obstructive sleep apnea.

METHODS

This qualitative and quantitative analysis was conducted between July 2017 and November 2019 on patients suspected of sleep apnea. The quantitative analysis aimed at determining the rate of adherence through a retrospective cross-sectional study. The qualitative content analysis was conducted on purposefully selected subgroup of patients suspected of obstructive sleep apnea who were referred for polysomnography. The required data were collected through the semi-structured in-depth interviews and then recorded, transcribed, and analyzed using SPSS.22 and MAXQDA10.

RESULTS

Quantitative part: Of 311 patients (mean age: 47.6 ± 13.1 years) referred for polysomnography, 283 patients (91%) were at a high risk of developing obstructive sleep apnea. Among those referred for polysomnography, 31% (n = 95) adhered to recommendations for a sleep study. Qualitative part: Factors affecting adherence to polysomnography were categorized as "barriers" and "triggers." Barriers included inadequate knowledge, psychological factors, cost, and the service system. Triggers included adequate knowledge and tangible experience of consequences of the illness.

CONCLUSION

The majority of patients at risk of developing obstructive sleep apnea did not follow the recommendation for polysomnography, indicating a need for systematic interventions. Among the identified barriers, knowledge and psychological factors are modifiable ones that can be addressed with the patient. We theorize that raising awareness among patients by providing additional information and eliminating concerns may help to increase the rate of adherence. Insurance coverage or subsidy to reduce the sleep study costs may also be an effective strategy to increase adherence to recommendations for polysomnography.

Technologic advances in the assessment and management of obstructive sleep apnoea beyond the apnoea-hypopnoea index: a narrative review

Obstructive sleep apnoea (OSA) is a growing and serious worldwide health problem with significant health and socioeconomic consequences. Current diagnostic testing strategies are limited by cost, access to resources and over reliance on one measure, namely the apnoea-hypopnoea frequency per hour (AHI). Recent evidence supports moving away from the AHI as the principle measure of OSA severity towards a more personalised approach to OSA diagnosis and treatment that includes phenotypic and biological traits. Novel advances in technology include the use of signals such as heart rate variability (HRV), oximetry and peripheral arterial tonometry (PAT) as alternative or additional measures. Ubiquitous use of smartphones and developments in wearable technology have also led to increased availability of applications and devices to facilitate home screening of at-risk populations, although current evidence indicates relatively poor accuracy in comparison with the traditional gold standard polysomnography (PSG). In this review, we evaluate the current strategies for diagnosing OSA in the context of their limitations, potential physiological targets as alternatives to AHI and the role of novel technology in OSA. We also evaluate the current evidence for using newer technologies in OSA diagnosis, the physiological targets such as smartphone applications and wearable technology. Future developments in OSA diagnosis and assessment will likely focus increasingly on systemic effects of sleep disordered breathing (SDB) such as changes in nocturnal oxygen and blood pressure (BP); and may also include other factors such as circulating biomarkers. These developments will likely require a re-evaluation of the diagnostic and grading criteria for clinically significant OSA.

Toward standardizing the clinical testing protocols of point-of-care devices for obstructive sleep apnea diagnosis

PURPOSE

In recent years, point-of-care (POC) devices, especially smart wearables, have been introduced to provide a cost-effective, comfortable, and accessible alternative to polysomnography (PSG)-the current gold standard-for the monitoring, screening, and diagnosis of obstructive sleep apnea (OSA). Thorough validation and human subject testing are essential steps in the translation of these device technologies to the market. However, every device development group tests their device in their own way. No standard guidelines exist for assessing the performance of these POC devices. The purpose of this paper is to critically distill the key aspects of the various protocols reported in the literature and present a protocol that unifies the best practices for testing wearable and other POC devices for OSA.

METHODS

A limited review and graphical descriptive analytics of literature-including journal articles, web sources, and clinical manuscripts by authoritative agencies in sleep medicine-are performed to glean the testing and validation methods employed for POC devices, specifically for OSA.

RESULTS

The analysis suggests that the extent of heterogeneity of the demographics, the performance metrics, subject survey, hypotheses, and statistical analyses need to be carefully considered in a systematic protocol for testing POC devices for OSA.

CONCLUSION

We provide a systematic method and list specific recommendations to extensively assess various performance criteria for human subject testing of POC devices. A rating scale of 1-3 is provided to encourage studies to put a focus on addressing the key elements of a testing protocol.

Night-to-night variability of respiratory events in obstructive sleep apnoea: a systematic review and meta-analysis

Background

It is current practice to use a single diagnostic sleep study in the diagnostic workup of obstructive sleep apnoea (OSA). However, a relevant night-to-night variability (NtNV) of respiratory events has been reported.

Methods

We evaluated the NtNV of respiratory events in adults with suspected or already diagnosed OSA who underwent more than one diagnostic sleep study. Data sources were PubMed, Cochrane and Embase up to 23 January 2019. Random-effects models were used for evidence synthesis. For moderator analysis, mixed-effects regression analysis was performed. The study was registered with PROSPERO (CRD42019135277).

Results

Of 2143 identified papers, 24 studies, comprising 3250 participants, were included. The mean Apnoea-Hypopnoea Index (AHI) difference between the first and second night was −1.70/hour (95% CI −3.61 to 0.02). REM time differences (first to second night) were significantly positive associated with differences in mean AHI (β coefficient 0.262 (95% CI 0.096 to 0.428). On average, 41% (95% CI 27% to 57%) of all participants showed changes of respiratory events >10/hour from night to night. Furthermore, 49% (95% CI 32% to 65%) of participants changed OSA severity class (severity thresholds at 5/hour, 15/hour and 30/hour) at least once in sequential sleep studies. Depending on the diagnostic threshold (5/hour, 10/hour or 15/hour), on average 12% (95% CI 9% to 15%), 12% (95% CI 8% to 19%) and 10% (95% CI 8% to 13%) of patients would have been missed during the first night due to single night testing.

Conclusion

While there was no significant difference between mean AHI in two sequential study nights on a group level, there was a remarkable intraindividual NtNV of respiratory events, leading to misdiagnosis and misclassification of patients with suspected OSA.

Association between adherence to continuous positive airway pressure treatment and cost among medicare enrollees

OBJECTIVE

To analyze the cost associated with sleep apnea and effects of continuous positive airway pressure (CPAP) treatment on costs among fee-for-service Medicare beneficiaries.

METHODS

Retrospective cohort design using 5% Medicare claims between 2006 and 2010. Medicare beneficiaries with and without sleep apnea diagnosis between 2007 and 2008 were identified and followed retrospectively for 2 years pre-index-date and 2 years post-index-date. We defined CPAP fill as at least one durable medical equipment claim for CPAP in 6-month period. At least three CPAP fills was defined as "full adherence," and one or two CPAP fills was "partial adherence." We used interrupted time series and generalized linear log-link models to study the association between sleep apnea, CPAP treatment, and costs. To minimize bias, we used propensity score and instrumental variables approach.

RESULTS

Sleep apnea was associated with higher costs (odds ratio [OR] = 1.60; 95% confidence interval [CI] = 1.58, 1.63) compared to those without sleep apnea. Almost half of those with sleep apnea received CPAP treatment. Interrupted time series analysis indicated post level increase in mean monthly cost for full CPAP adherence group, partial CPAP adherence group and no-CPAP group. However, the increase was smallest for the full CPAP adherence group. Full CPAP adherence was associated with lower change in cost (OR = 0.92; 95% CI = 0.88, 0.97) compared to the no-CPAP group.

CONCLUSIONS

Medicare beneficiaries with sleep apnea experience increased cost. Full adherence to CPAP treatment for sleep apnea was associated with lower increase in cost. These findings emphasize the need to effectively identify and treat sleep apnea in Medicare patients.

Global burden of sleep-disordered breathing and its implications

One-seventh of the world's adult population, or approximately one billion people, are estimated to have OSA. Over the past four decades, obesity, the main risk factor for OSA, has risen in striking proportion worldwide. In the past 5 years, the WHO estimates global obesity to affect almost two billion adults. A second major risk factor for OSA is advanced age. As the prevalence of the ageing population and obesity increases, the vulnerability towards having OSA increases. In addition to these traditional OSA risk factors, studies of the global population reveal select contributing features and phenotypes, including extreme phenotypes and symptom clusters that deserve further examination. Untreated OSA is associated with significant comorbidities and mortality. These represent a tremendous threat to the individual and global health. Beyond the personal toll, the economic costs of OSA are far-reaching, affecting the individual, family and society directly and indirectly, in terms of productivity and public safety. A better understanding of the pathophysiology, individual and ethnic similarities and differences is needed to better facilitate management of this chronic disease. In some countries, measures of the OSA disease burden are sparse. As the global burden of OSA and its associated comorbidities are projected to further increase, the infrastructure to diagnose and manage OSA will need to adapt. The use of novel approaches (electronic health records and artificial intelligence) to stratify risk, diagnose and affect treatment are necessary. Together, a unified multi-disciplinary, multi-organizational, global approach will be needed to manage this disease.

Association of sleep-disordered breathing with total healthcare costs and utilization in older men: the Outcomes of Sleep Disorders in Older Men (MrOS Sleep) study

STUDY OBJECTIVES

To determine the associations of sleep-disordered breathing (SDB) with subsequent healthcare costs and utilization including inpatient and post-acute care facility stays among community-dwelling older men.

METHODS

Participants were 1,316 men (mean age 76.1 [SD = 5.7] years) in the Outcomes of Sleep Disorders in Older Men (MrOS sleep) study (from December 2003 to March 2005), who were enrolled in a Medicare Fee-For-Service plan. Primary SDB measures including apnea hypopnea index (AHI) and oxygen desaturation index (ODI) were collected using in-home level 2 polysomnography. Incident healthcare costs and utilization were determined from claims data in the subsequent 3-year period post-MrOS sleep visit.

RESULTS

Five hundred and twenty-nine (40.2%) men had at least one hospitalization in the 3-year period. Compared with those without sleep apnea (AHI < 5/hour), men with moderate to severe sleep apnea (AHI ≥ 15/hour) had a higher odds of all-cause hospitalization (odds ratio [OR] adjusted for age and site 1.43, 95% confidence interval [CI]: 1.07-1.90). This association was slightly attenuated after further adjustment for traditional prognostic factors including education, body mass index, comorbid medical conditions, and health status (OR = 1.36; 95% CI: 1.01-1.83). Similar associations were observed for ODI. However, measures of SDB were not related to subsequent healthcare costs (total or outpatient) or odds of post-acute skilled nursing facility stay.

CONCLUSIONS

Older men with SDB have an increased risk of hospitalization, not entirely explained by the greater prevalence of comorbid conditions, but not higher subsequent total healthcare costs. These findings indicate a need to evaluate the impact of SDB treatment on subsequent healthcare utilization.

Ankylosing Spondylitis Is Associated With Risk of New-Onset Obstructive Sleep Apnea: A Nationwide Population-Based Cohort Study

Objectives: Investigating the risk of obstructive sleep apnea(OSA) among ankylosing spondylitis (AS) patients based on administrative healthcare databases.

Methods: We conducted a nationwide cohort study by using the Taiwan National Health Insurance Research Database with 1997–2013 claim records. The AS cohort included 2,210 patients who were newly diagnosed between 2003 and 2013. Randomly selected non-AS controls were matched at a 1:4 ratio. The endpoint was set as OSA occurrence or the end of 2013. Cumulative incidences, hazard ratios (HRs) and 95% confidence intervals (CIs) were calculated after adjusting for age, gender, comorbidities, and co-medication. Multivariate analyses were performed using the Cox proportional hazards model. Due to the violation of the proportionality assumption, landmark analysis was conducted to explore the risk of OSA during specific follow-up periods.

Results: The adjusted HR (aHR) of OSA in the AS group was 2.826 (95% C.I. = 1.727–4.625) compared to the control group. On landmark analysis, aHR was 7.919 (95% C.I. = 3.169–19.792) for the AS group 0–24 months from the index date and decreased to 1.816 (95% C.I. = 0.944–3.494) at ≥ 24 months from the index date. The increased risks of OSA in the AS group compared to the control group were found for both males and females (aHRs were 4.533 and 2.672). On age-stratified analysis, a significant risk only for the 40–59 age group with aHR of 3.913 (95% C.I. = 1.890–8.102).

Conclusions: A higher risk of developing OSA was found among newly diagnosed AS cohort during the maximum 11-year follow-up period, especially within 2 years after newly diagnosed AS and in the 40–59 age group.

Effects of suboptimal adherence of CPAP therapy on symptoms of obstructive sleep apnoea: a randomised, double-blind, controlled trial

Introduction

Continuous positive airway pressure (CPAP) is currently the treatment of choice for sleepiness in patients with obstructive sleep apnoea (OSA); however, adherence is often thought to be suboptimal. We investigated the effects of suboptimal CPAP usage on objective and subjective sleepiness parameters in patients with OSA.

Material and methods

In this 2-week, parallel, double-blind, randomised controlled trial we enrolled moderate-to-severe OSA patients with excessive pre-treatment daytime sleepiness (Epworth sleepiness scale (ESS) score >10 points) who had suboptimal CPAP adherence over ≥12 months (mean nightly usage time 3–4 h). Patients were allocated through minimisation to either subtherapeutic CPAP (“sham CPAP”) or continuation of CPAP (“therapeutic CPAP”). A Bayesian analysis with historical priors calculated the posterior probability of superiority.

Results

Between May, 2016 and November, 2018, 57 patients (aged 60±8 years, 79% male, 93% Caucasian) were allocated in total, and 52 who completed the study (50% in each arm) were included in the final analysis. The unadjusted ESS score increase was 2.4 points (95% CI 0.6–4.2, p=0.01) in the sham-CPAP group when compared to continuing therapeutic CPAP. The probability of superiority of therapeutic CPAP over sham CPAP was 90.4% for ESS, 90.1% for systolic blood pressure and 80.3% for diastolic blood pressure.

Conclusions

Patients with moderate-to-severe OSA and daytime sleepiness are still getting a substantial benefit from suboptimal CPAP adherence, albeit not as much as they might get if they adhered more. Whether a similar statement can be made for even lower adherence levels remains to be established in future trials.

Quality and readability of online information on dental treatment for snoring and obstructive sleep apnea

PURPOSE

To evaluate quality and readability of online information on dental treatment for snoring and obstructive sleep apnea.

METHODS

An Internet search was done using three engines (Bing, Google, and Yahoo) with the combination of terms, "snoring sleep apnea dental treatment". The first 100 sites from the search of each engine were screened. Subject sites were evaluated with Health on the Net(HON) criteria, Journal of American Medical Association(JAMA) benchmarks, DISCERN, Ensuring Quality Information for Patients(EQIP), Flesch-Kincaid Grade level and Flesch Reading Ease(FRE) score.

RESULTS

One hundred and thirty websites were evaluated. The HON, DISCERN, EQIP, and FRE score were each 39.4%, 47.3%, 49.7%, and 51.6% of the maximum possible score, respectively. According to JAMA benchmarks fewer than 50% of the sites displayed attribution and currency. There was only one site displaying the HON seal. HON score, DISCERN score and EQIP score showed significant inter-correlation.

CONCLUSION

Based on this study, the current quality and readability of searchable websites on dental treatment for snoring and sleep apnea are low and poorly maintained on average. Clinicians should be able to evaluate and give accurate online information on this issue to patients.

Influence function-based empirical likelihood for inference of quantile medical costs with censored data

In this paper, we propose empirical likelihood methods based on influence function and Jackknife techniques to construct confidence intervals for quantile medical costs with censored data. We show that the influence function-based empirical log-likelihood ratio statistic for the quantile medical cost has a standard Chi-square distribution as its asymptotic distribution. Simulation studies are conducted to compare coverage probabilities and interval lengths of the proposed empirical likelihood confidence intervals with the existing normal approximation-based confidence intervals for quantile medical costs. The proposed methods are observed to have better finite-sample performances than existing methods. The new methods are also illustrated through a real example.

Association of Positive Airway Pressure Use With Acute Care Utilization and Costs

STUDY OBJECTIVES

The current value-based medical climate has led to scrutiny of all medical costs. Given the relationship between obstructive sleep apnea (OSA) and many significant comorbid medical conditions, treating patients with OSA via positive airway pressure (PAP) therapy might reduce health care expenditures. Our goal was to determine the relationship between PAP use and acute care utilization and costs.

METHODS

This was a retrospective cohort study of adult patients who initiated PAP therapy after a diagnosis of moderate-severe OSA at a large integrated health system during 2014-2016.

RESULTS

The study consisted of 1,098 patients, of which 60% were on PAP > 4 h/night for ≥ 70% of the nights. The average h/night were 5.3 (standard deviation 2.4). Increasing PAP usage was associated with reduced inpatient (rate ratio [RR] 0.92, 95% confidence interval [CI] 0.86-0.98) and overall acute care visits (RR 0.96, 95% CI 0.92-0.99). The linear relationships were supported by the threshold effects identified in the categorical adherence measures. No linear association was identified with emergency department visits and inpatient stays. However, lower number of emergency department visits (RR 0.78, 95% CI 0.62-0.98) and inpatient stays (RR 0.56, 95% CI 0.35-0.91) were observed among adherent (> 4 h/night for ≥ 70% of the nights) patients.

CONCLUSIONS

PAP usage was linearly associated with reduced number of inpatient and overall acute care visits, and lower likelihood of having positive costs from these visits. PAP usage was also associated with less emergency department visits and inpatient stays when comparing adherent patients to less adherent patients.

CITATION

Kirsch DB, Yang H, Maslow AL, Stolzenbach M, McCall A. Association of positive airway pressure use with acute care utilization and costs. J Clin Sleep Med. 2019;15(9):1243-1250.

Cost-effectiveness of continuous positive airway pressure therapy for obstructive sleep apnea: health care system and societal perspectives

Study Objectives

To determine cost-effectiveness of continuous positive airway pressure (CPAP) treatment of obstructive sleep apnea (OSA) in Australia for 2017–2018 to facilitate public health decision-making.

Methods

Analysis was undertaken of direct per-person costs of CPAP therapy (according to 5-year care pathways), health system and other costs of OSA and its comorbidities averted by CPAP treatment (5-year adherence rate 56.7%) and incremental benefit of therapy (in terms of disability-adjusted life years [DALYs] averted) to determine cost-effectiveness of CPAP. This was expressed as the incremental cost-effectiveness ratio (= dollars per DALY averted). Direct costs of CPAP were estimated from government reimbursements for services and advertised equipment costs. Costs averted were calculated from both the health care system perspective (health system costs only) and societal perspective (health system plus other financial costs including informal care, productivity losses, nonmedical accident costs, deadweight taxation and welfare losses). These estimates of costs (expressed in US dollars) and DALYs averted were based on our recent analyses of costs of untreated OSA.

Results

From the health care system perspective, estimated cost of CPAP therapy to treat OSA was $12 495 per DALY averted while from a societal perspective the effect was dominant (−$10 688 per DALY averted) meaning it costs more not to treat the problem than to treat it.

Conclusions

These estimates suggest substantial community investment in measures to more systematically identify and treat OSA is justified. Apart from potential health and well-being benefits, it is financially prudent to do so.

Obstructive sleep apnea: personal, societal, public health, and legal implications

Introduction Obstructive sleep apnea (OSA) is a widely prevalent sleep-related breathing disorder, which leads to several life-threatening diseases. OSA has systemic effects on various organ systems. Untreated OSA is associated with long-term health consequences including hypertension, heart disease, diabetes, depression, metabolic disorders, and stroke. In addition, untreated OSA is reported to be associated with cognitive dysfunction, impaired productivity at the workplace and in an increased risk of motor vehicle accidents (MVAs) resulting in injury and fatality. Other consequences of OSA include, but are not limited to, impaired vigilance, daytime somnolence, performance deficits, morning headaches, mood disturbances, neurobehavioral impairments, and general malaise. Additionally, OSA has become an economic burden on most health systems all over the world. Many driving license regulations have been developed to reduce MVAs among OSA patients. Methods Studies of the personal, societal, public health, and legal aspects of OSA are reviewed. Data were collected through the following databases: MEDLINE, Google Scholar, Scopus, SAGE Research Methods, and ScienceDirect. Conclusion OSA leads to worsening of patients' personal relationships, decreasing work productivity, and increasing occupational accidents as well as MVAs. The costs of undiagnosed and untreated OSA to healthcare organizations are excessive. Thus, proper management of OSA will benefit not only the patient but will also provide widespread benefits to the society as a whole.

Comparison of nocturnal pulse oximetry with polysomnography in children with sleep disordered breathing

PURPOSE

Polysomnography (PSG) is the gold standard in the diagnosis of obstructive sleep apnea (OSA). However, due to high cost and limited availability, this is difficult to access and often delayed. To evaluate the reliability of overnight oximetry as a screening tool for OSA diagnosis.

METHOD

All children suspected of OSA who underwent an overnight oximetry and subsequent PSG between January 2014 and April 2016 were studied retrospectively. The "McGill oximetry scoring" was compared with OSA diagnosis as per the American Association of Sleep Medicine.

RESULTS

A total of 110 patients had both oximetry and PSG. Sixty-one children (56%) had normal oximetry, whereas 30 (27%) had McGill grade 2 and 19 (17%) had McGill 3 and 4. Sixty-four percent (64%) of children with normal oximetry had a normal PSG. Seventy percent (70%) of children with McGill 2 had either a normal or mild OSA on PSG. All the children with McGill 3 and 4 had moderate/severe OSA by PSG. The overall sensitivity and specificity of oximetry in identifying OSA were 63% and 78%, respectively, and the positive and negative predictive values (PPV and NPV) were 78% and 64%, respectively. The sensitivity and specificity of McGill 3 and 4 in diagnosing moderate/severe OSA on PSG were 59% and 100%, respectively, and the PPV and NPV were 100% and 78%, respectively.

CONCLUSION

Overnight oximetry provides satisfactory diagnostic performance in detecting moderate and severe OSA; however, a normal or McGill 2 score does not rule out OSA and a PSG is required for diagnosis.