Expenditure on health care in obese women with and without sleep apnea

The Cost-Effectiveness of Sleep Apnea Management: A Critical Evaluation of the Impact of Therapy on Health Care Costs

TOPIC IMPORTANCE

OSA is a widespread condition that significantly affects both health and health-related quality of life (HRQoL). If left untreated, OSA can lead to accidents, decreased productivity, and medical complications, resulting in significant economic burdens including the direct costs of managing the disorder. Given the constraints on health care resources, understanding the cost-effectiveness of OSA management is crucial. A key factor in cost-effectiveness is whether OSA therapies reduce medical costs associated with OSA-related complications.

REVIEW FINDINGS

Treatments for OSA have been shown to enhance HRQoL, particularly for symptomatic patients with moderate or severe disease. Economic studies also have demonstrated that these treatments are highly cost-effective. However, although substantial empirical evidence shows that untreated OSA is associated with increased medical costs, uncertainty remains about the impact of OSA treatment on these costs. Randomized controlled trials of positive airway pressure (PAP) therapy have failed to demonstrate cost reductions, but the studies have had important limitations. Observational studies suggest that PAP therapy may temper increases in costs, but only among patients who are highly adherent to treatment. However, the healthy adherer effect is an important potential source of bias in these studies.

SUMMARY

OSA management is cost-effective, although uncertainties persist regarding the therapy's impact on medical costs. Future studies should focus on reducing bias, particularly the healthy adherer effect, and addressing other confounding factors to clarify potential medical cost savings. Promising avenues to further understanding include using quasiexperimental designs, incorporating more sophisticated characterization of OSA severity and symptoms, and leveraging newer technologies (eg, big data, wearables, and artificial intelligence).

The economic cost of obstructive sleep apnea: A systematic review

Obstructive sleep apnea (OSA) is a common disease associated with a high prevalence of costly comorbidities and accidents that add to the disease's economic impact. Although more attention has been focused on OSA in recent years, no previous systematic reviews have synthesized findings from existing studies that provide estimates of the economic cost of OSA. This study aims to summarize the findings of existing studies that provide estimates of the cost of OSA. Two bibliographic databases, PubMed and Scopus, were used to identify articles on the costs of OSA. The systematic literature review identified 5,938 publications, of which 31 met the inclusion criteria. According to the results, adjusted for inflation and converted to euros, the annual cost per patient ranged from €236 (the incremental cost of OSA) for New Zealand to €28,267 for the United States. The total annual cost per patient in Europe ranged from €1,669 to €5,186. OSA causes a significant burden on society, and OSA-related costs increase many years before the diagnosis and remain elevated for a long time after the diagnosis. Despite some well-conducted studies, the cost estimates for OSA are uncertain and specific to the context in which the study was conducted.

Occult, undiagnosed obstructive sleep apnea increases risk of depression among a national sample of older adult Medicare beneficiaries

STUDY OBJECTIVES

To determine the association between occult, undiagnosed obstructive sleep apnea and incident depression among a nationally representative sample of older adult Medicare beneficiaries.

METHODS

Our data source was a random 5% sample of Medicare administrative claims data for the years 2006-2013. Occult, undiagnosed obstructive sleep apnea was defined as the 12-month period preceding receipt of one or more International Classification of Disease, Version 9, Clinical Modification diagnostic codes for obstructive sleep apnea. To determine the effect of obstructive sleep apnea on incident depression, beneficiaries with undiagnosed obstructive sleep apnea were matched on index date to a random sample of nonsleep disordered controls (ie, individuals without evidence of sleep-related testing, diagnosis, or treatment). After excluding beneficiaries with preexisting depression, the risk of depression was modeled as a function of occult, undiagnosed obstructive sleep apnea status over the 12months prior to obstructive sleep apnea diagnosis using log-binomial regression. Covariates were balanced between groups using inverse probability of treatment weights.

RESULTS

The final sample included 21,116 beneficiaries with occult, undiagnosed obstructive sleep apnea and 237,375 nonsleep disordered controls. In adjusted models, beneficiaries with occult, undiagnosed obstructive sleep apnea demonstrated a significantly higher risk of depression during the year prior to obstructive sleep apnea diagnosis (risk ratio 3.19; 95% confidence interval 3.00, 3.39).

CONCLUSIONS

In this national study of Medicare beneficiaries and relative to nonsleep disordered controls, occult, undiagnosed obstructive sleep apnea was associated with a significantly higher risk for incident depression.

Undiagnosed obstructive sleep apnea increases risk of hospitalization among a racially diverse group of older adults with comorbid cardiovascular disease

STUDY OBJECTIVES

Undiagnosed obstructive sleep apnea (OSA) is associated with increased risk for subsequent cardiovascular events, hospitalizations, and mortality. The primary objective of this study was to determine the association between undiagnosed OSA and subsequent hospitalizations among older adults with preexisting cardiovascular disease (CVD). A secondary objective was to determine the risk of 30-day hospital readmission associated with undiagnosed OSA among older adults with CVD.

METHODS

This was a retrospective cohort study of a 5% sample of Medicare administrative claims data for years 2006-2013. Beneficiaries aged 65 years and older diagnosed with CVD were included. Undiagnosed OSA was defined as the 12-month period prior to OSA diagnosis. A similar 12-month period among beneficiaries not diagnosed with OSA was used for the comparison group (no OSA). Our primary outcome was the first all-cause hospital admission. Among beneficiaries with a hospital admission, 30-day readmission was assessed for the first hospital admission only.

RESULTS

Among 142,893 beneficiaries diagnosed with CVD, 19,390 had undiagnosed OSA. Among beneficiaries with undiagnosed OSA, 9,047 (46.7%) experienced at least 1 hospitalization whereas 27,027 (21.9%) of those without OSA experienced at least 1 hospitalization. Following adjustment, undiagnosed OSA was associated with increased risk of hospitalization (odds ratio 1.82; 95% confidence interval 1.77, 1.87) relative to no OSA. Among beneficiaries with ≥ 1 hospitalization, undiagnosed OSA was associated with a smaller but significant effect in weighted models (odds ratio 1.18; 95% confidence interval 1.09, 1.27).

CONCLUSIONS

Undiagnosed OSA was associated with significantly increased risk of hospitalization and 30-day readmissions among older adults with preexisting CVD.

CITATION

Kirk J, Wickwire EM, Somers VK, Johnson DA, Albrecht JS. Undiagnosed obstructive sleep apnea increases risk of hospitalization among a racially diverse group of older adults with comorbid cardiovascular disease. J Clin Sleep Med. 2023;19(7):1175-1181.

Patient-reported Differences in Obstructive Sleep Apnea Care between Jurisdictions with and without Government Funding for Continuous Positive Airway Pressure

Rationale: Funding for obstructive sleep apnea (OSA) treatment may impact how patients access care, wait times, and costs of care. Objectives: The aim of this study was to compare differences in diagnosis and treatment of OSA between Canadian jurisdictions with and without public funding for continuous positive airway pressure (CPAP). Methods: We administered an anonymous internet survey to Canadian adults reporting a physician diagnosis of OSA. Responses were categorized on the basis of whether the respondent's province provided full or partial funding for CPAP therapy for all patients. We assessed wait times for diagnosis and treatment, patient-borne costs, and model of care delivery compared between jurisdictions with and without universal CPAP funding. Results: We received 600 responses representing all Canadian provinces and territories. The median (interquartile range) age was 59 (49-66) years; 57% were male, and 21% were from rural settings. Patients living in provinces without public CPAP funding (n = 419) were more likely to be diagnosed using home sleep apnea testing (69% vs. 20%; P = 0.00019). Wait times were similar after adjustment for demographics, disease characteristics, and model of care. Although patient-borne costs of care were similar between jurisdictions, patients from regions without CPAP funding reported that cost had a greater influence on the choice of therapy. Sleep specialists were more commonly involved in OSA care in regions with CPAP funding. There was no difference in the current use of therapy between jurisdictions with and without public funding. Conclusions: This survey study demonstrates that public funding for CPAP therapy impacts how Canadians access OSA care but is not associated with differences in wait times or costs. Future research is required to determine the impact of different funding models for OSA care on clinical outcomes.

Adherence to continuous positive airway pressure reduces the risk of 30-day hospital readmission among older adults with comorbid obstructive sleep apnea and cardiovascular disease

STUDY OBJECTIVES

Obstructive sleep apnea (OSA) is underdiagnosed and undertreated among patients hospitalized with comorbid cardiovascular disease (CVD). Treatment of OSA may reduce health care utilization, but benefits of continuous positive airway pressure (CPAP) therapy are related to adherence. Benefits of CPAP among hospitalized individuals with OSA and CVD have not been well studied. We evaluated the effect of CPAP adherence on 30-day hospital readmission among Medicare beneficiaries hospitalized with OSA and CVD.

METHODS

We conducted a retrospective cohort study of Medicare beneficiaries aged ≥ 65 years with pre-existing CVD who were newly diagnosed with OSA between 2009 and 2013, initiated CPAP, and were hospitalized. CPAP adherence was defined as nonadherent, partially adherent, or highly adherent based on the number of machine charges (< 4, 4-12, and > 12, respectively) over 25 months of follow-up. The primary outcome was 30-day hospital readmission.

RESULTS

Among 1,301 beneficiaries meeting study criteria, the 30-day readmission rate was 10.2%. In adjusted models and compared to patients with low CPAP adherence, those with high adherence had lower odds of 30-day readmission (odds ratio 0.41; 95% confidence interval 0.24-0.70). The protective effect of high CPAP adherence on 30-day readmission was significant among beneficiaries with heart failure (odds ratio 0.50; 95% confidence interval 0.16, 0.79), but not among those with other CVD.

CONCLUSIONS

In this nationally representative sample of older adults with CVD and comorbid OSA, high CPAP adherence was associated with lower odds of 30-day readmission. These results highlight the importance of screening for and treating OSA among individuals with CVD.

CITATION

Bailey MD, Wickwire EM, Somers VK, Albrecht JS. Adherence to continuous positive airway pressure reduces the risk of 30-day hospital readmission among older adults with comorbid obstructive sleep apnea and cardiovascular disease. J Clin Sleep Med. 2022;18(12):2739-2744.

National strategy on the integration of sleep and circadian rhythms into public health research and policies: Report from the Canadian Sleep and Circadian Network

Scientists in sleep and circadian rhythms, public health experts, healthcare providers, partners, and stakeholders convened in 2020 for a 2-day meeting organized by the Canadian Sleep and Circadian Network to develop a national strategy for the integration of sleep and circadian rhythms into public health and policies in Canada. The objective of this paper is to present the national strategy that emerged from this meeting of 60 participants from across Canada. The meeting focused on 4 key target priorities: (1) atypical working schedules, (2) sleep and circadian rhythms of children and adolescents, (3) insomnia, and (4) impact of sleep apnea on health. Following constructive discussions over 2 days, it was decided that the following 4 strategic objectives should be prioritized to accelerate the integration of sleep and circadian rhythms into public health policies in Canada: (1) Increase public health sleep and circadian rhythm research, (2) Increase public health education and knowledge mobilization on sleep, (3) Inform and support public health sleep interventions and policies, and (4) Promote sleep health training. The participants recommended that research and public health efforts should address the needs along the continuum of sleep health. The committee noted that strategies and interventions could differ across contexts, settings, sectors, and jurisdictions. The national strategy also identified high-priority research questions in public health and recommended mechanisms to build research capacity, providing a path forward for the integration of sleep and circadian rhythms into public health research and policies.

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.

Economic evaluation of CPAP therapy for obstructive sleep apnea: a scoping review and evidence map

PURPOSE

To synthesize findings of economic evaluations investigating cost-effectiveness of continuous positive airway pressure (CPAP) for obstructive sleep apnea (OSA) and of strategies of organization of care related to CPAP therapy.

METHODS

Scoping review with searches conducted in MEDLINE, CRD, LILACS, and Embase in August 2020. Eligible studies were economic evaluations comparing CPAP to other alternative or assessing strategies of care for CPAP therapy. Results were presented narratively, and incremental cost-effectiveness ratios (ICER) were presented in evidence maps.

RESULTS

Of 34 studies, 3 concluded that CPAP is less costly and more effective when compared to usual care. Most studies indicated that CPAP is associated with better health outcomes, but at higher prices. ICER ranged from USD 316 to 98,793 per quality-adjusted life years (QALY) gained (median 16,499; IQR 8267 to 33,119). One study concluded that CPAP is more costly and less effective, when treatment is applied to all patients, regardless of disease severity. Variability of ICER was mainly due to definition of population and applied time horizons. When CPAP was compared to mandibular advancement device, ICER ranged from USD 21,153 to 361,028 (median 89,671; IQR 26,829 to 295,983), which represents the investment in CPAP therapy required to obtain one extra QALY. Three studies assessed the effects of organizing CPAP therapy in primary care, which was cost-effective or cost-saving.

CONCLUSIONS

Compared to usual care, CPAP is cost-effective after the second year of treatment, when indicated for moderate-to-severe OSA. CPAP therapy may be even more cost-effective by using different strategies of organization of care. These findings may inform decision making related to CPAP reimbursement in health systems.

CLINICAL TRIAL REGISTRATION NUMBER

Not applicable.

CPAP adherence is associated with reduced inpatient utilization among older adult Medicare beneficiaries with pre-existing cardiovascular disease

STUDY OBJECTIVES

To examine the impact of adherence to continuous positive airway pressure (CPAP) therapy on health care utilization among a nationally representative and sample of older adults with multiple morbidities and pre-existing cardiovascular disease and subsequently diagnosed with obstructive sleep apnea in the United States.

METHODS

Our data source was a random 5% sample of Medicare administrative claims data. All participants (n = 1,921) were of age ≥ 65 years, diagnosed with cardiovascular disease and obstructive sleep apnea, and subsequently began treatment with CPAP between 2009-2013. Based on the number of CPAP machine charges, individuals were categorized as low, partial, or high adherers (ie, < 4, 4-12, and > 12 CPAP charges, respectively). The impact of CPAP adherence status on health care utilization was assessed across multiple points of service, including outpatient encounters, inpatient stays, emergency department visits, and prescription fills over 24 months following CPAP initiation.

RESULTS

Significant differences in demographic and comorbid disease characteristics were observed between low adherers (n = 377), partial adherers (n = 236), and high adherers (n = 1,308). After adjusting for covariates and relative to low adherers, high adherers demonstrated reduced inpatient visits (hazard ratio 0.75; 95% confidence interval 0.57, 0.97).

CONCLUSIONS

In this nationally representative sample of older Medicare beneficiaries with multiple morbidities and relative to low adherers, high adherers demonstrated reduced inpatient utilization.

CITATION

Wickwire EM, Bailey MD, Somers VK, et al. CPAP adherence is associated with reduced inpatient utilization among older adult Medicare beneficiaries with pre-existing cardiovascular disease. J Clin Sleep Med. 2022;18(1):39-45.

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.

Perspectives on primary care management of obstructive sleep apnea: a qualitative study of patients and health care providers

STUDY OBJECTIVES

Difficulties in providing timely access to care have prompted interest in primary care delivery models for obstructive sleep apnea (OSA). Sustainable implementation of such models requires codesign with input from key stakeholders. The purpose of this study was to identify patient and provider perspectives on barriers and facilitators to optimal, patient-centered management of OSA in a primary care setting.

METHODS

This study was conducted in Alberta, Canada. Data from key stakeholders were collected through an online survey of primary care providers (n = 119), focus groups and interviews with patients living with OSA (n = 28), and workshops with primary care and sleep providers (n = 36). Quantitative survey data were reported using descriptive statistics, and qualitative data were analyzed using an inductive thematic approach.

RESULTS

Several barriers were identified, including poor specialist access, variable primary care providers knowledge of OSA, and lack of clarity about provider roles for OSA management. Barriers contributed to patients being poorly informed about OSA, leading them to separate OSA from their overall health and eroding trust in the system. Suggestions for improvement included integration of care providers in a comprehensive model of care, facilitated by improved system navigation and more effective use of technology. Themes were consistent across data collection methods and between stakeholder groups.

CONCLUSIONS

Although primary care delivery models may improve access to OSA management, stakeholders identified important challenges in the current system. Innovative models of care, developed with input from patients and providers, may mitigate barriers and support optimal primary care management of OSA.

CPAP adherence is associated with reduced risk for stroke among older adult Medicare beneficiaries with obstructive sleep apnea

STUDY OBJECTIVES

To examine the impact of adherence to continuous positive airway pressure (CPAP) therapy on risk of stroke among a nationally representative sample of older adults with obstructive sleep apnea.

METHODS

We performed a retrospective cohort study among Medicare beneficiaries aged ≥ 65 years who were newly diagnosed with obstructive sleep apnea and had initiated CPAP (2009-2013). Monthly indicators of CPAP adherence included charges for machines, masks, or supplies and were summed over a 25-month follow-up to create a CPAP adherence variable. Stroke was modeled as a function of CPAP adherence using generalized estimating equations.

RESULTS

We found that 5,757 beneficiaries met the inclusion criteria and were included in the final sample. Of these, 407 (7%) experienced stroke. After adjusting for demographic and clinical characteristics, CPAP adherence was associated with a reduced risk of stroke (hazard ratio, 0.98; 95% confidence interval, 0.96-0.99) over 25 months, indicating a 2% reduction in risk of stroke for each month of CPAP adherence. When sensitivity analyses were performed to stratify results by time since the first CPAP charge, the protective effect remained significant for the 12- and 6-month but not the 3-month outcome models.

CONCLUSIONS

In this national analysis of older adult Medicare beneficiaries with obstructive sleep apnea, CPAP adherence was associated with significantly reduced risk of stroke.

Lower socioeconomic status and co-morbid conditions are associated with reduced continuous positive airway pressure adherence among older adult medicare beneficiaries with obstructive sleep apnea

STUDY OBJECTIVES

To examine rates of adherence to continuous positive airway pressure (CPAP) therapy among a representative sample of older adult Medicare beneficiaries with obstructive sleep apnea (OSA), and to identify demographic and health-related factors associated with CPAP adherence.

METHODS

Using a 5% sample of Medicare claims data, we utilized Medicare policy and CPAP machine charges as a proxy for CPAP adherence. A cumulative logit model was used to identify demographic, medical, and psychiatric predictors of CPAP adherence status.

RESULTS

Of beneficiaries who initiated CPAP (n = 3,229), 74.9% (n = 2,417) met the so-called "90-day Medicare adherence criteria," but only 58.8% of these individuals (n = 1,420) continued to use CPAP throughout the entire 13-month rent-to-own period. Anxiety, anemia, fibromyalgia, traumatic brain injury, and lower socioeconomic status (SES) were all associated with reduced CPAP adherence.

CONCLUSIONS

These results provide the first national estimates of CPAP adherence among older adult Medicare beneficiaries in the United States. In addition, findings highlight the salience of medical and psychiatric comorbidity, as well as SES, as important markers of CPAP adherence among older adults in the United States. Future studies should seek to evaluate interventions to improve CPAP adherence among older adults of lower SES.

Effects of Exercise in Patients with Obstructive Sleep Apnoea

Obstructive sleep apnoea (OSA) constitutes a public health problem, with various systemic consequences that can increase cardiovascular morbidity and mortality as well as increase healthcare expenditure. This review discusses the rationale and effects of using general physical exercise, oropharyngeal exercises, and respiratory muscle training as an adjunctive treatment for patients with sleep apnoea. The recommended treatment for OSA is the use of continuous positive airway pressure, which is a therapy that prevents apnoea events by keeping the airways open. In the last decade, coadjuvant treatments that aim to support weight loss (including diet and physical exercise) and oropharyngeal exercises have been proposed to lower the apnoea/hypopnoea index among patients with OSA. Based on the available evidence, health professionals could decide to incorporate these therapeutic strategies to manage patients with sleep apnoea.

Alternative Care Pathways for Obstructive Sleep Apnea and the Impact on Positive Airway Pressure Adherence: Unraveling the Puzzle of Adherence

The high burden of obstructive sleep apnea (OSA), combined with inadequate supply of sleep specialists and constraints on polysomnography resources, has prompted interest in alternative models of care to improve access and treatment effectiveness. In appropriately selected patients, ambulatory clinical pathways and use of nonphysicians or primary care providers to manage OSA can improve timely access and costs without compromising adherence or other clinical outcomes. Although initial studies show promising results, there are several potential barriers that must be considered before broad implementation, and further implementation research and economic evaluation studies are required.

CPAP adherence reduces cardiovascular risk among older adults with obstructive sleep apnea

STUDY OBJECTIVES

To examine (1) the impact of adherence to continuous positive airway pressure (CPAP) therapy on risk for cardiovascular (CVD) events among a nationally representative sample of older adults with obstructive sleep apnea (OSA), and (2) the heterogeneity of this effect across subgroups defined by race, sex, and socioeconomic status.

METHODS

We conducted a retrospective cohort study among Medicare beneficiaries aged ≥ 65 years with OSA (2009-2013). Monthly indicators of CPAP adherence (charges for machines, masks, or supplies) were summed over 25 months to create a CPAP adherence variable. New CVD events (ischemic heart disease, cardiac and peripheral procedures) were modeled as a function of CPAP adherence using generalized estimating equations. Heterogeneity of the effect of CPAP on new CVD events was evaluated based on race, sex, and socioeconomic status.

RESULTS

Among 5024 beneficiaries diagnosed with OSA who initiated CPAP, 1678 (33%) demonstrated new CVD events. Following adjustment for demographic and clinical characteristics, CPAP adherence was associated with reduced risk of new CVD events (hazard ratio 0.95; 95% confidence interval 0.94, 0.96) over 25 months. When analyses were stratified by time since the first CPAP charge, the protective effect remained significant for the 12- and 6-month, but not 3-month, outcome models. No significant differences were observed in the protective effect of CPAP based on race, sex, or socioeconomic status.

CONCLUSIONS

In this national study of older adult Medicare beneficiaries with OSA, CPAP adherence was associated with greatly reduced risk for CVD events. This risk reduction was consistent across race, sex, and socioeconomic subgroups.

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.

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.

Older adult US Medicare beneficiaries with untreated obstructive sleep apnea are heavier users of health care than matched control patients

STUDY OBJECTIVES

To examine the effect of untreated obstructive sleep apnea (OSA) on health care utilization (HCU) and costs among a nationally representative sample of Medicare beneficiaries.

METHODS

Our data source was a random 5% sample of Medicare administrative claims data for years 2006-2013. OSA was operationalized as (1) receipt of one or more International Classification of Disease, Version 9, Clinical Modification diagnostic codes for OSA in combination with (2) initiation of OSA treatment with either continuous positive airway pressure or oral appliance (OA) therapy. First, HCU and costs were assessed during the 12 months prior to treatment initiation. Next, these HCU and costs were compared between beneficiaries with OSA and matched control patients without sleep-disordered breathing using generalized linear models.

RESULTS

The final sample (n = 287,191) included 10,317 beneficiaries with OSA and 276,874 control patients. In fully adjusted models, during the year prior to OSA diagnosis and relative to matched control patients, beneficiaries with OSA demonstrated increased HCU and higher mean total annual costs ($19,566, 95% confidence interval [CI] $13,239, $25,894) as well as higher mean annual costs across all individual points of service. Inpatient care was associated with the highest incremental costs (ie, greater than control patients; $15,482, 95% CI $8,521, $22,443) and prescriptions were associated with the lowest incremental costs (ie, greater than control patients; $431, 95% CI $339, $522).

CONCLUSIONS

In this randomly selected and nationally representative sample of Medicare beneficiaries and relative to matched control patients, individuals with untreated OSA demonstrated increased HCU and costs across all points of service.

Does Providing Positive Airway Pressure for Sleep Apnea Change Health Care Utilization?

BACKGROUND

Sleep apnea is underdiagnosed and thus undertreated. If therapy for sleep apnea results in reduced health care utilization in an entire treated population, then decision-makers will have key information for allocating limited health care resources.

OBJECTIVES

To determine whether positive airway pressure (PAP) for sleep apnea was associated with reduced health care utilization in an entire treated population.

RESEARCH DESIGN

This was a retrospective cohort; propensity score-matched cases and noncases; pre-post analyses of individual subject utilization.

SUBJECTS

Electronic health records were used to identify adult subjects diagnosed with sleep apnea and dispensed PAP therapy (cases) and those without either diagnosed sleep apnea or dispensed PAP therapy (noncases).

MEASURES

Acute care hospital days and dispensed medication days supply were compared in cases and noncases. Negative binomial regression was used to model utilization for up to 5 years before and 7 years after PAP dispensation (cases) or a random date (noncases). The association of PAP with changing annual utilization was estimated.

RESULTS

There were 13,271 cases and 13,271 matched noncases from 2008 to 2012 for analyses. Trends in the annual rate of acute care utilization were no different between cases and noncases (rate ratio, 0.98, P=0.543). Trends in the annual rate of medication utilization were no different between cases and noncases (rate ratio, 1.008, P=0.112).

CONCLUSIONS

PAP dispensation for sleep apnea did not appear to reduce the rate of acute care and medication utilization over several years of follow-up in a large integrated health care system.

Circulating exosomes in obstructive sleep apnea as phenotypic biomarkers and mechanistic messengers of end-organ morbidity

Obstructive sleep apnea (OSA), the most severe form of sleep disordered breathing, is characterized by intermittent hypoxia during sleep (IH), sleep fragmentation, and episodic hypercapnia. OSA is associated with increased risk for morbidity and mortality affecting cardiovascular, metabolic, and neurocognitive systems, and more recently with non-alcoholic fatty liver disease (NAFLD) and cancer-related deaths. Substantial variability in OSA outcomes suggests that genetically-determined and environmental and lifestyle factors affect the phenotypic susceptibility to OSA. Furthermore, OSA and obesity often co-exist and manifest activation of shared molecular end-organ injury mechanisms that if properly identified may represent potential therapeutic targets. A challenge in the development of non-invasive diagnostic assays in body fluids is the ability to identify clinically relevant biomarkers. Circulating extracellular vesicles (EVs) include a heterogeneous population of vesicular structures including exosomes, prostasomes, microvesicles (MVs), ectosomes and oncosomes, and are classified based on their size, shape and membrane surface composition. Of these, exosomes (30-100nm) are very small membrane vesicles derived from multi-vesicular bodies or from the plasma membrane and play important roles in mediating cell-cell communication via cargo that includes lipids, proteins, mRNAs, miRNAs and DNA. We have recently identified a unique cluster of exosomal miRNAs in both humans and rodents exposed to intermittent hypoxia as well as in patients with OSA with divergent morbid phenotypes. Here we summarize such recent findings, and will focus on exosomal miRNAs in both adult and children which mediate intercellular communication relevant to OSA and endothelial dysfunction, and their potential value as diagnostic and prognostic biomarkers.

Value from the Patients' and Payers' Perspectives

Health care costs continue to increase, and the approach of countries and insurers is to focus on the value of the care delivered. Value is a function of quality in relation to costs. The perspective of the individual measuring value is important. Calculation of costs may include return to work if the employer's perspective is taken. The patients' perspectives include out-of-pocket expenses and work lost for both patients and potentially caregivers. The authors provide one example in the area of sleep apnea in which the anesthesiologist can provide value uniquely by being part of the team making the diagnosis.

Age protects from harmful effects produced by chronic intermittent hypoxia

Obstructive sleep apnoea (OSA) affects an estimated 3–7% of the adult population, the frequency doubling at ages >60–65 years. As it evolves, OSA becomes frequently associated with cardiovascular, metabolic and neuropsychiatric pathologies defining OSA syndrome (OSAS). Exposing experimental animals to chronic intermittent hypoxia (CIH) can be used as a model of the recurrent hypoxic and O2 desaturation patterns observed in OSA patients. CIH is an important OSA event triggering associated pathologies; CIH induces carotid body (CB)-driven exaggerated sympathetic tone and overproduction of reactive oxygen species, related to the pathogenic mechanisms of associated pathologies observed in OSAS. Aiming to discover why OSAS is clinically less conspicuous in aged patients, the present study compares CIH effects in young (3–4 months) and aged (22–24 months) rats. To define potential distinctive patterns of these pathogenic mechanisms, mean arterial blood pressure as the final CIH outcome was measured. In young rats, CIH augmented CB sensory responses to hypoxia, decreased hypoxic ventilation and augmented sympathetic activity (plasma catecholamine levels and renal artery content and synthesis rate). An increased brainstem integration of CB sensory input as a trigger of sympathetic activity is suggested. CIH also caused an oxidative status decreasing aconitase/fumarase ratio and superoxide dismutase activity. In aged animals, CIH minimally affected CB responses, ventilation and sympathetic-related parameters leaving redox status unaltered. In young animals, CIH caused hypertension and in aged animals, whose baseline blood pressure was augmented, CIH did not augment it further. Plausible mechanisms of the differences and potential significance of these findings for the diagnosis and therapy of OSAS are discussed.

The effect of sex and age on the comorbidity burden of OSA: an observational analysis from a large nationwide US health claims database

Obstructive sleep apnoea (OSA) is a highly prevalent condition but studies exploring the burden of OSA-associated comorbidities have been limited by small sample sizes with underrepresentation of women.

We queried the Truven Health MarketScan Research Databases 2003–2012, which is a collection of health insurance claims for working adults and retirees with employer-sponsored health insurance. Adults with a diagnostic code for OSA with at least 12 months of follow-up from the index date of OSA diagnosis were compared to a matched random sample. Comorbidities were assessed using International Classification of Diseases, Ninth Edition, codes. A logistic regression model was constructed to test the independent association between OSA and comorbidities.

Our cohort included 1 704 905 patients with OSA and 1 704 417 matched controls. All comorbidities were significantly more prevalent in OSA patients. Type 2 diabetes and ischaemic heart disease were more prevalent in men but hypertension and depression were more prevalent in women with OSA. In contrast, the sex differences in the prevalence of congestive heart failure, arrhythmias and stroke were less pronounced. The prevalence of comorbidities increased with age but the effect of age varied based on the specific comorbidity. The divergence between OSA and controls was more pronounced after the sixth decade of life for most cardiovascular diseases (i.e.heart failure, ischaemic heart disease, stroke and arrhythmias), while depression exhibited an opposite trend. In a fully adjusted model, the odds of all comorbidities were significantly increased in OSA patients.

In a large, nationally representative sample of working and retired people, OSA is strongly associated with significant comorbidities in both men and women with unique sex differences emerging.

Clinical consequences and economic costs of untreated obstructive sleep apnea syndrome

Objective

To provide an overview of the healthcare and societal consequences and costs of untreated obstructive sleep apnea syndrome.

Data sources

PubMed database for English-language studies with no start date restrictions and with an end date of September 2014.

Methods

A comprehensive literature review was performed to identify all studies that discussed the physiologic, clinical and societal consequences of obstructive sleep apnea syndrome as well as the costs associated with these consequences. There were 106 studies that formed the basis of this analysis.

Conclusions

Undiagnosed and untreated obstructive sleep apnea syndrome can lead to abnormal physiology that can have serious implications including increased cardiovascular disease, stroke, metabolic disease, excessive daytime sleepiness, work-place errors, traffic accidents and death. These consequences result in significant economic burden. Both, the health and societal consequences and their costs can be decreased with identification and treatment of sleep apnea.

Implications for practice

Treatment of obstructive sleep apnea syndrome, despite its consequences, is limited by lack of diagnosis, poor patient acceptance, lack of access to effective therapies, and lack of a variety of effective therapies. Newer modes of therapy that are effective, cost efficient and more accepted by patients need to be developed.

Healthcare Service Utilization by Patients with Obstructive Sleep Apnea: A Population-Based Study

OBJECTIVE

Although obstructive sleep apnea (OSA) is not a life-threatening disease, very few studies have compared differences in healthcare service utilization between patients with and those without OSA in an Asian population according to different age groups. This study attempted to investigate differences in healthcare service utilization between patients with and those without OSA in different age groups in Taiwan.

METHODS

Sampled subjects and data on their health service utilization were retrieved from the Taiwan Longitudinal Health Insurance Database 2005. We included 568 patients with OSA and 2840 subjects without OSA. Each subject was followed for a 1-year period to evaluate their healthcare resource utilization. Wilcoxon-Mann-Whitney tests were performed to compare differences in healthcare utilization between patients with and those without OSA during the 1-year follow-up period.

RESULTS

As to all healthcare service utilization, patients with OSA had significantly more outpatient visits (30.3 vs. 18.6), outpatient costs (US$1231.2 vs. US$764.8), inpatient days (1.8 vs. 1.2), inpatient costs (US$563.6 vs. US$276.7), and total costs (US$1794.8 vs. US$1041.5) than comparison subjects during the 1-year follow-up period. Moreover, patients with OSA aged 40~49 and 50~59 years respectively incurred 2.11- and 2.02-fold higher total costs compared to patients without OSA. However, patients with OSA aged over 70 years did not have higher total costs compared to those without OSA.

CONCLUSIONS

This study found that patients with OSA had greater healthcare service utilization than those without OSA. Additionally, patients with OSA in the 40~49- and 50~59-year age groups had about 2-fold higher total costs of healthcare services than those without OSA.

Gender differences in sleep disordered breathing: implications for therapy

There are gender differences in the upper airway function and respiratory stability in obstructive sleep apnea (OSA). Hormones are implicated in some gender-related differences, and these differences between men and women appear to mitigate as age increases. In addition, changes in the airway and lung function during pregnancy can contribute to snoring and OSA that might have an adverse effect on the mother and fetus. The limited data available suggest that although the prevalence and severity of OSA may be lower in women, the consequences of the disease are similar, if not worse. Women with OSA may have greater risk for hypertension and endothelial dysfunction, be more likely to develop comorbid conditions such as anxiety and depression and have increased mortality. Therefore, treatment options specifically targeting female presentations and pathophysiology of sleep-disordered breathing (SDB) are expected to result in improved outcomes in women.

A Matched Cohort Study of Postoperative Outcomes in Obstructive Sleep Apnea

Background:

Obstructive sleep apnea (OSA) is associated with increased risk of postoperative complications. The authors investigated whether preoperative diagnosis and prescription of continuous positive airway pressure therapy reduces these risks.

Methods:

Matched cohort analysis of polysomnography data and Manitoban health administrative data (1987 to 2008). Postoperative outcomes in adult OSA patients up to 5 yr before (undiagnosed OSA, n = 1,571), and any time after (diagnosed OSA, n = 2,640) polysomnography and prescription of continuous positive airway pressure therapy for a new diagnosis of OSA, were compared with controls at low risk of having sleep apnea (n = 16,277). Controls were matched by exact procedure, indication, and approximate date of surgery. Procedures used to treat sleep apnea were excluded. Follow-up was at least 7 postoperative days. Results were reported as odds ratio (95% CI) for OSA or subgroup versus controls.

Results:

In multivariate analyses, the risk of respiratory complications (2.08 [1.35 to 3.19], P &lt; 0.001) was similarly increased for both undiagnosed and diagnosed OSA. The risk of cardiovascular complications, primarily cardiac arrest and shock, was significantly different (P = 0.009) between undiagnosed OSA (2.20 [1.16 to 4.17], P = 0.02) and diagnosed OSA patients (0.75 [0.43 to 1.28], P = 0.29). For both outcomes, OSA severity, type of surgery, age, and other comorbidities were also important risk modifiers.

Conclusions:

Diagnosis of OSA and prescription of continuous positive airway pressure therapy were associated with a reduction in postoperative cardiovascular complications. Despite limitations in the data, these results could be used to justify and inform large efficacy trials of perioperative continuous positive airway pressure therapy in OSA patients.

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.

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.

Medicare long-term CPAP coverage policy: a cost-utility analysis

STUDY OBJECTIVES

CPAP is an effective treatment for OSA that may reduce health care utilization and costs. Medicare currently reimburses the costs of long-term CPAP therapy only if the patient is adherent during a 90-day trial. If not, Medicare requires a repeat polysomnogram (PSG) and another trial which seems empirically not cost-effective. We modeled the cost-effectiveness of current Medicare policy compared to an alternative policy (clinic-only) without the adherence criterion and repeat PSG.

DESIGN

Cost-utility and cost-effectiveness analysis.

SETTING

U.S. Medicare Population.

PATIENTS OR PARTICIPANTS

N/A.

INTERVENTIONS

N/A.

MEASUREMENTS AND RESULTS

We created a decision tree modeling (1) clinic only follow-up vs. (2) current Medicare policy. Costs were assigned based on Medicare reimbursement rates in 2012. Sensitivity analyses were conducted to test our assumptions. We estimated cumulative costs, overall adherence, and QALY gained for a 5-year time horizon from the perspective of Medicare as the payer. Current Medicare policy is more costly than the clinic-only policy but has higher net adherence and improved utility. Current Medicare policy compared to clinic-only policy costs $30,544 more per QALY.

CONCLUSIONS

Current CMS policy promotes early identification of those more likely to adhere to CPAP therapy by requiring strict adherence standards. The policy effect is to deny coverage to those unlikely to use CPAP long-term and prevent wasted resources. Future studies are needed to measure long-term adherence in an elderly population with and without current adherence requirements to verify the cost-effectiveness of a policy change.

Morbidity prior to a diagnosis of sleep-disordered breathing: a controlled national study

BACKGROUND

Sleep-disordered breathing (SDB) causes burden to the sufferer, the healthcare system, and society. Most studies have focused on cardiovascular diseases (CVDs) after a diagnosis of obstructive sleep apnea (OSA) or obesity hypoventilation syndrome (OHS); however, the overall morbidity prior to an SDB diagnosis has not been evaluated. The aim of this study was to identify morbidity prior to a SDB diagnosis to identify patients at risk for having/developing SDB.

METHODS

Using data from the Danish National Patient Registry (1998-2006), we identified all patients nationwide given a diagnosis of OSA (19,438) or OHS (755) in all hospitals and clinics. For each patient, we randomly selected 4 citizens matched for age, sex, and socioeconomic status from the Danish Civil Registration System Statistics.

RESULTS

Patients with OSA or OHS presented with increased morbidity at least 3 years prior to their SDB diagnosis. The most common contacts with the health system (odds ratio [OR]/confidence interval [CI]) for OSA/OHS were due to musculoskeletal system (1.36[1.29-1.42]/1.35[1.05-1.74]); CVD (1.38[1.30-1.46]/1.80[1.38-2.34]); endocrine, nutritional, and metabolic diseases (1.62[1.50-1.76]/4.10[2.90-5.78]); diseases of the nervous system (1.62[1.0-1.76]/3.54[2.56-4.88]); respiratory system (1.84[1.73-1.96]/2.83[2.07-3.89]); skin and subcutaneous tissue (1.18[1.07-1.30]/2.12[1.33-3.38]); gastrointestinal (1.17[1.10-1.24]/NS); infections (1.20[1.08-1.33]/NS); genitourinary system (1.21[1.13-1.30]/NS); and ear, nose, and throat (1.44[1.32-1.56]/NS).

CONCLUSIONS

Patients with SDB show significant morbidities several years prior to a diagnosis of OSA or OHS. OSA should be considered in all medical specialties as an important comorbidity. In our study, evidence points to particular emphasis for considering this diagnosis in endocrinology and metabolic specialties.

A comparison of disease-specific medical expenditures in Japan using the principal diagnosis method and the proportional distribution method

BACKGROUND

There are technical limitations to handling all the information mentioned in health insurance claims (HICs) in Japan. Therefore, conventional methods for estimating disease-specific medical expenditures assume that all medical care expenditures in a given HIC are spent on only one principal diagnosis even when the HIC contains multiple diagnoses.

OBJECTIVES

To estimate the disease-specific medical expenditures that consider all diagnosis on a given HIC.

METHODS

Data were obtained from 169 622 outpatient HICs in May 2006 from health insurance provided by the employer. We compared the estimated disease-specific medical expenditures of the conventional method with a proportional distribution method (PDM), which considers all diagnoses on the HICs.

RESULTS

For diabetes mellitus and other diseases of the digestive system, the proportion of principal diagnoses among total diagnoses was 52.4% (4849/9251) and 19.6% (2614/13331), respectively. In addition, the ratio of the estimated disease-specific medical expenditures between the conventional method and the PDM method was 1.49 for diabetes mellitus and 0.64 for other diseases of the digestive system. The estimation of disease-specific medical expenditures using the conventional method may therefore have overestimated the expenditures on the disease category typically selected as the principal diagnosis and underestimated the expenditures on the disease category less likely to be selected as the principal diagnosis.

CONCLUSIONS

The conventional method for estimation of disease-specific medical expenditures should be improved by utilizing all the diagnoses information on HICs.

Sleep disorders and demand for medical services: evidence from a population-based longitudinal study

Background

The aim of this study was to investigate whether insomnia and obstructive sleep apnea (OSA) were predictors of hospitalizations or emergency department visits during two years following the Sao Paulo Epidemiologic Sleep Study (EPISONO) sample.

Methods and Findings

All participants (n = 1,101) who underwent a baseline evaluation between July and December 2007 were contacted in December 2009 and asked to fill out a questionnaire about body weight changes, number of hospitalizations and visits to the emergency department. Participants lost during the follow-up period represented 3.2% (n = 35) and 7 subjects had died. Hospitalizations were reported by 116 volunteers (10.5%) and emergency department visits were reported by 136 participants (12.4%). The average body mass index (BMI) did not vary significantly between the first and the second assessment [26.7(95%CI:26.3–27.1) vs. 26.9(26.5–27.4) kg/m2]. After adjusting for confounders, a multiple logistic regression model revealed that female gender [1.4(1.0–1.9)], age ≥40 years, insomnia diagnosed according to the DSM-IV criteria [1.6(1.0–2.6)], and apnea-hypopnea index ≥15 [1.5(1.0–2.2)] were predictors of hospitalizations and/or demand for emergency services.

Conclusion

Our study of a probabilistic sample of the Sao Paulo inhabitants shows that over a period of two years, insomnia and OSA were both associated with health impairment. Considering the high prevalence and public health burden of sleep disorders, the consequences of untreated disease for both the individual and society are undeniable and should be addressed.

Some reflections on intermittent hypoxia. Does it constitute the translational niche for carotid body chemoreceptor researchers?

The views presented in this article are the fruit of reflections and discussion with my colleagues at Valladolid and with the members of the Sleep Apnea Hypopnea Syndrome Group of the CIBERES (Spain). We have assembled the article in three sections. In the first one we provide a mechanistic description of obstructive sleep apnea (OSA) and all of its components, including the repetitive episodes of upper airways (UA) obstruction and accompanying hypoxic hypoxia, the respiratory efforts to fight and overcome the obstruction, and the sleep fragmentation due to the hypoxia-triggered arousal reactions, all events occurring during sleep hours with frequencies that might reach up >40-50 episodes/sleep hour. When OSA is accompanied by some of the elements of a big cohort of associated pathologies (vascular, metabolic, and neuropsychiatric) it conforms the obstructive sleep apnea syndrome (OSAS). The high frequency of OSAS in adults (>35 years old) and the costs in every regard of the treatment makes the syndrome a primary importance socio-sanitary problem. In the second section, we describe the experimental models of OSAS, basically the episodic repetitive hypoxic model described by Fletcher and coworkers in 1992, today named in short intermittent hypoxia (IH). From these lines, we want to call for some kind of consensus among researchers to lessen the dispersion of IH protocols. Finally, in the last section we intend to share our optimism with all ISAC members. The optimism is based on the recognition that carotid body (CB) chemoreceptors are critical elements of one of the main pathophysiologic loops in the genesis of OSAS. Therefore, we believe that all of us, as ISAC members, are well qualified to contribute in multidisciplinary research teams with well defined translational interests.

Excessive daytime sleepiness is associated with increased health care utilization among patients referred for assessment of OSA

STUDY OBJECTIVES

Excessive daytime sleepiness is an important public health concern associated with increased morbidity and mortality. However, in the absence of sleep diagnostic testing, it is difficult to separate the independent effects of sleepiness from those of intrinsic sleep disorders such as obstructive sleep apnea (OSA). The objective of this study was to determine if excessive daytime sleepiness was independently associated with increased health care utilization among patients referred for assessment of OSA.

DESIGN

Cross-sectional study.

SETTING/PARTICIPANTS

2149 adults referred for sleep diagnostic testing between July 2005 and August 2007.

INTERVENTIONS

N/A.

MEASUREMENTS

Subjective daytime sleepiness was defined as an Epworth Sleepiness Scale score ≥10. Health care use (outpatient physician visits, all-cause hospitalizations, and emergency department visits) was determined from Alberta Health and Wellness administrative databases for the 18-month period preceding their sleep study. Rates of health resource use were analyzed using negative binomial regression, with predictors of increased health care use determined using logistic regression.

RESULTS

excessive daytime sleepiness was associated with an increased rate of outpatient physician visits after adjustment for demographic variables, sleep medication use, hypertension, diabetes, depression, and OSA severity (rate ratio [RR]: 1.09 (95% confidence interval [CI]: 1.01, 1.18, P = 0.02) compared to non-sleepy subjects. There was an interaction between severe OSA and sleepiness (RR: 1.22 [95% CI: 1.06, 1.41]), although OSA was not an independent predictor of health care use. Also, sleepy patients with treated depression had a lower likelihood of outpatient visits (RR: 0.95 [95% CI: 0.86, 1.05]). Finally, sleepiness was an independent predictor of increased health care use for outpatient physician visits (odds ratio [OR]: 1.25 [95% CI: 1.00, 1.57; P = 0.048]) and all-cause hospitalizations (OR: 3.94 [95% CI: 1.03, 15.04; P = 0.046]).

CONCLUSIONS

Excessive daytime sleepiness is associated with increased health care utilization among patients referred for assessment of OSA. Further investigation is required to determine whether the findings are related to direct effects of sleepiness, or in part, to interactions with other comorbidity such as OSA.