Beyond CPAP: modifying upper airway output for the treatment of OSA

Obstructive Sleep Apnea (OSA) is exceedingly common but often under-treated. Continuous positive airway pressure (CPAP) has long been considered the gold standard of OSA therapy. Limitations to CPAP therapy include adherence and availability. The 2021 global CPAP shortage highlighted the need to tailor patient treatments beyond CPAP alone. Common CPAP alternative approaches include positional therapy, mandibular advancement devices, and upper airway surgery. Upper airway training consists of a variety of therapies, including exercise regimens, external neuromuscular electrical stimulation, and woodwind instruments. More invasive approaches include hypoglossal nerve stimulation devices. This review will focus on the approaches for modifying upper airway muscle behavior as a therapeutic modality in OSA.

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.

0758 Behavioral Determinants of PAP Use in Veterans with COMISA: Results of a Randomized Trial

Introduction

Nonadherence to positive airway pressure (PAP) therapy is common in comorbid insomnia and obstructive sleep apnea (COMISA). We previously reported a novel behavioral treatment for COMISA which improves both PAP adherence and sleep. Our current goal was to assess whether improvements in PAP self-efficacy, knowledge, and decisional balance (targets of treatment) are associated with improvements in PAP use and sleep quality. We also collected participants’ perceptions of benefits and challenges of PAP during intervention.

Methods

125 veterans (96% men, 39% non-Hispanic white, 24% Black, 17% Hispanic/Latino) with COMISA were randomized to a 5-week intervention integrating behavioral insomnia therapy with a PAP adherence program versus general sleep education (control). Objective PAP use data and Pittsburgh Sleep Quality Index (PSQI) were collected over 6 months. Three behavior change subscales (PAP Self-Efficacy [PAP-SE], Decisional Balance Index [DBI], Knowledge [KNOW]) were administered at 6-months. Weekly self-report of participant-perceived benefits and challenges of PAP use were collected among intervention participants. Subscale scores, PAP use and PSQI were compared between intervention and control, and associations were tested. Change in mean number of benefits and challenges of PAP use were also tested (all analyses intent-to-treat).

Results

At 6-months, compared to controls, intervention participants had higher scores on all three subscales: PAP-SE (4.1 intervention versus 3.5 control, respectively), DBI (8.3, 0.9) and KNOW (10.5, 9.6, all p<.05). Intervention participants had more PAP use and lower (better) PSQI scores at 6-months (all p<.05). In the total sample, PAP use and PSQI correlated with PAP-SE (r=.52 PAP use, r=-.27 PSQI, respectively), DBI (r=.49, -.35) and KNOW (r=.43, -.21; all p<.05). Among intervention participants, perceived benefits of PAP increased over time (4.3 at week 2, 5.8 at week 4, respectively), and challenges decreased (3.7, 2.3; all p<.05).

Conclusion

Behavioral treatment for COMISA improves behavioral determinants of PAP use, which is associated with improvements in PAP use and sleep quality. In addition, with treatment, perceived benefits of PAP increase and challenges decrease. These findings suggest improvements in self-efficacy, knowledge and perceived benefits of PAP are important mechanisms through which behavioral interventions improve PAP use in older adults with COMISA.

Support (If Any)

VAHSRD (IIR12–353-Alessi, RCSA20-191-Martin) and NIH (NHLBI K24HL143055-Martin, NIA K23AG049955-Dzierzewski)

0773 When CPAPs are in Short Supply: A Review of Other FDA Approved OSA Interventions

Introduction

The CPAP recall of 2021 has highlighted an inherent problem that occurs when a field of medicine is overly dependent on a single class of medical devices to treat a condition. The global shortage of CPAP devices has led to numerous individuals with OSA being unable to obtain a CPAP machine to treat their condition, including those with severe OSA. CPAP is well known to be efficacious in treating OSA, but has limited effectiveness, particularly for mild-to-moderate cases. It has been reported that there are nearly 200 different medical devices approved by the FDA to treat OSA. The goal of this project was to search the FDA databases to investigate the number of devices currently on file with the FDA. A secondary goal was to examine the range of FDA product categories for the treatment of OSA.

Methods

An FDA database (AccessGUDID; https://accessgudid.nlm.nih.gov) with a release date of December 1, 2021 was searched for devices that are approved for the treatment of sleep apnea. The text string “sleep apnea” was used for the search. Diagnostic devices, duplicate versions of the same treatment devices, and device accessories were excluded from the total counts. The FDA classifies medical devices into three categories (I, II, III), with a higher classification level indicating greater risk to patients.

Results

The FDA AccessGUDID database search returned 166 results, which resulted in 72 unique devices across 10 product code categories. 9 of the 10 product codes in the FDA database were class II (medium risk) and 1/10 was classified as III (high risk). 65 of the devices were reported to be in commercial distribution at the time of the search and 7 were not.

Conclusion

This analysis found that a relatively large number of FDA-approved devices exist for the treatment of OSA across a range of product categories. The field is encouraged to develop a better understanding of which subgroups of OSA patients could benefit from alternative forms of treatment in an effort to diversify treatment options and reduce the field’s reliance on a single type of device, particularly for patients with mild-to-moderate OSA.

Support (If Any)

VA IIR 16-277

Outcomes Important to Patients Diagnosed with Both COPD and Sleep Apnea: Findings from the O2VERLAP Study Focus Groups

INTRODUCTION

Few studies have asked chronic obstructive pulmonary disease (COPD) -obstructive sleep apnea (OSA) overlap syndrome patients what outcomes of continuous positive airway pressure (CPAP) therapy are important to them, while also considering their self-reported CPAP adherence barriers and facilitators. This study conducted a series of focus groups to learn about those issues with the goal of applying these findings to the design of a larger Patient-Centered Outcomes Research Institute-funded scientific study, the O2VERLAP Study.

METHODS

People previously diagnosed with both COPD and OSA, who were current or recent past users of the standard therapy for each condition (i.e., supplemental oxygen and CPAP, respectively), were included. Three qualitative focus groups were run using different communication modalities: (1) teleconference (audio only), (2) in-person, and (3) web-based.

RESULTS

The focus groups included a total of 17 participants. The telephone and online focus groups resulted in more relevant and content-rich transcripts, while the in-person focus groups had far fewer excerpts able to be coded. Participants were most concerned about mask fit and comfort. Other key factors affecting CPAP use included nasal dryness and issues concerning insurance. The most important outcome to patients was daytime functioning.

DISCUSSION

This work found that telephone and web-based qualitative focus groups resulted in greater topical discussions than in-person focus groups, likely due to the customary socializing that occurs in-person. The study identified: (1) CPAP use barriers and facilitators that helped guide intervention development for the larger study and, (2) daytime functioning as the most important outcome for patients.

Indirect treatment comparison of solriamfetol, modafinil, and armodafinil for excessive daytime sleepiness in obstructive sleep apnea

STUDY OBJECTIVES

Excessive daytime sleepiness associated with obstructive sleep apnea affects 9%-22% of continuous positive airway pressure-treated patients. An indirect treatment comparison meta-analysis was performed to compare efficacy and safety of medications (solriamfetol, modafinil, and armodafinil) approved to treat excessive daytime sleepiness associated with obstructive sleep apnea.

METHODS

Efficacy and safety measures assessed in this indirect treatment comparison included Epworth Sleepiness Scale (ESS), 20-minute Maintenance of Wakefulness Test (MWT20), Clinical Global Impression of Change (CGI-C), Functional Outcomes of Sleep Questionnaire (FOSQ), and incidence of treatment-emergent adverse events (any, serious, or leading to discontinuation).

RESULTS

A systematic literature review identified 6 parallel-arm, placebo-controlled randomized controlled trials that randomized 1,714 total participants to placebo, solriamfetol, modafinil, or armodafinil. In this indirect treatment comparison, all comparators were associated with greater improvements than placebo on the ESS, MWT20, and CGI-C after 4, 8, and 12 weeks of treatment. Relative to comparators and placebo at 12 weeks, solriamfetol at 150 mg or 300 mg had the highest probabilities of improvement in the ESS, MWT20, and CGI-C. Modafinil (200 or 400 mg) and solriamfetol (150 or 300 mg) were associated with greater improvement on the FOSQ than placebo at 12 weeks. Less than 2% of patients using placebo or comparators experienced serious or discontinuation-related treatment-emergent adverse events.

CONCLUSIONS

The results of this indirect treatment comparison show 12 weeks of treatment with solriamfetol, modafinil, and armodafinil resulted in varying levels of improvement on the ESS, MWT20, and CGI-C and similar safety risks in participants with excessive daytime sleepiness associated with obstructive sleep apnea.

CITATION

Ronnebaum S, Bron M, Patel D, et al. Indirect treatment comparison of solriamfetol, modafinil, and armodafinil for excessive daytime sleepiness in obstructive sleep apnea. J Clin Sleep Med. 2021;17(12):2543-2555.

101 Measurement of Tapping During the Interstimulus Interval as a Validation Metric for the 3-Minute Psychomotor Vigilance Test

Introduction

The Psychomotor Vigilance Test is a well-validated measure of sustained attention used to assess daytime alertness in sleep research studies.1 It is commonly used in a variety of research settings due to its high sensitivity to sleep loss and absence of learning effects,2 making it an ideal tool to assess objective alertness. As some types of sleep research transition out of controlled laboratory environments, tools like the PVT require modification to maximize their reliability. The validation of the 3-minute version (PVT-B) against the 10-minute PVT is an example of this modification.3 However, considerable work is needed to improve trust in the utility of the PVT-B in and outside of traditional laboratory settings.

Methods

We carefully analyzed data from a mobile-based version of the PVT-B, noting responses that occurred during the interstimulus interval which were termed “wrong taps.” Wrong taps indicated that participants were not performing the task as instructed. In some cases, wrong taps occurred across multiple trials of the same PVT block, indicative of participants repeatedly tapping the screen throughout the task to minimize response times. A comprehensive examination of wrong taps was carried out in order to identify instances where this pattern emerged.

Results

A total of 1,338,538 PVT-B trials from 7,028 participants were examined to determine the number of wrong taps present across all trials. While 91.7% of PVT-B trials were free of wrong taps, 8.3% of PVT-B trials contained 1 or more wrong taps and 5.2% contained 2 or more wrong taps. It appears that a maximum of one wrong tap per trial is acceptable and trials containing 2 or more should be excluded to maximize PVT data quality.

Conclusion

Utilizing a metric like wrong taps can help identify individuals taking the PVT-B who are tapping the screen multiple times prior to stimulus display. Closely examining this metric can help to ensure the validity of PVT-B administrations. Two possible uses of the metric could be to provide feedback during training trials and to remove trials where this strategy was employed.

Support (if any)

This analysis was supported by the VA San Diego Healthcare System Research Service.

668 Utilizing Risk Score Assessment to Maximize Sleep Research Participant Safety During the COVID-19 Pandemic

Introduction

Research study recruitment has been profoundly affected by the COVID-19 pandemic, demonstrated by significant delays or pauses. Various guidelines pertaining to in-person visits have applied to research. Some call for exclusion of participants that the CDC has labeled “at increased risk”.1 For obstructive sleep apnea (OSA) studies, these guidelines have caused a sharp decrease in the number of new participants. This decrease is due to high rates of OSA comorbidities including obesity and diabetes. New evidence-based risk scores have been developed using individual- and community-level factors. The use of more refined COVID-19 risk scores can help protect patient safety while allowing research to continue.

Methods

The risk score assessment used for this study (COVID-19 Mortality Risk Calculator; Johns Hopkins University, Baltimore, MD)2 is evidence-based and uses a set of risk factors and community-level pandemic dynamics in the state of residence.3,4 It was compared to the list of CDC medical conditions that are considered to put an individual “at increased risk.” Both measures were calculated retrospectively on current participants to determine how many could safely attend in-person visits based on each risk assessment method.

Results

Sample characteristics of the 110 participants were: mean age: 49.5±13.7(24–76); mean BMI: 32.3±5.3(20.9–46.1); mean AHI: 24.3±21.4(5.1–110). Mortality Risk Calculator scores were: 91(82.7%) close to/lower than average [Level 1]; 12(10.9%) moderately elevated; 6(5.5%) substantially elevated; 1(0.9%) high; and 0(0%) very high [Level 5]. Using CDC guidance, 63 (57.3%) had at least one at-risk condition and 47 (42.7%) had 0. Using only Level 1 of the Risk Calculator would allow an additional 28 (25%) participants to attend in-person visits; using Levels 1 and 2 would allow an additional 40 (37%) participants.

Conclusion

Policies based on CDC at-risk conditions resulted in higher levels of participant exclusion in research during the COVID-19 pandemic than use of an evidence-based Mortality Risk Calculator. This analysis shows that researchers can use risk-adjusted scores to make informed decisions about study participation that balances both participant safety and research study progress.

Support (if any)

This project was supported in part by Department of Veteran Affairs VA HSRD IIR 16–277, VA RRD D2651-R, and VA San Diego Healthcare System Research Service.

435 Single Session CBT to Improve PAP Initiation and Adherence among Veterans with OSA

Introduction

Obstructive sleep apnea (OSA) is a condition that is prevalent, pernicious, and linked to the development and exacerbation of several disease processes. Positive airway pressure (PAP) is a highly efficacious intervention; however, initiation and adherence rates are poor. This represents a critical gap in care and a missed opportunity to reduce morbidity and mortality associated with OSA. The present study piloted a single session of cognitive behavioral therapy for treatment seeking (CBT-TS) among veterans diagnosed with obstructive sleep apnea and newly prescribed PAP.

Methods

Participants were asked to complete assessments at baseline and at two- and four-weeks post-intervention. A sample of 40 Veterans were enrolled in the study and completed a baseline interview, 27 completed CBT-TS. A matched comparison group of 64 veterans who did not receive the intervention was constructed using electronic medical record and PAP adherence data. Mann Whitney U and Chi Square tests were used to examine group differences in initiation and adherence.

Results

Participants who completed the CBT-TS session were more likely to initiate PAP (at least 3 consecutive nights of use) as compared to those receiving treatment as usual (TAU) [(CBT-TS; 96.3%; 26/27) versus (TAU; 64.1%; 41/64); X2(1, N = 91) = 10.16, p = .001]. Participants in the CBT-TS group also used their PAP devices for a greater number of nights over the first month than the comparison group [(CBT-TS; M = 21.7 (SD = 8.9), Mdn = 26.0) versus (TAU; M = 14.4 (SD = 12.6), Mdn = 15.5); U = 555.0, p = .007] and were more likely to use the device in an adherent manner (i.e., ≥4 hours use in an evening); [(CBT-TS; M = 15.1 (SD = 11.2); Mdn = 15.0) versus (TAU; M = 10.3 (SD = 11.2), Mdn = 6.5); U =630.0, p = .038].

Conclusion

These preliminary data suggest that CBT-TS may have utility in increasing initiation of PAP and subsequent treatment adherence among Veterans diagnosed with OSA and newly prescribed PAP.

Support (if any)

This work was supported by the VA Center of Excellence for Suicide Prevention in the Finger Lakes Healthcare System.

Randomized controlled trial of an integrated approach to treating insomnia and improving the use of positive airway pressure therapy in veterans with comorbid insomnia disorder and obstructive sleep apnea

STUDY OBJECTIVES

Cognitive behavioral therapy for insomnia (CBTI) for comorbid insomnia and obstructive sleep apnea (OSA) has had mixed results. We integrated CBTI with a positive airway pressure (PAP) adherence program and tested effects on sleep and PAP use.

METHODS

125 veterans (mean age 63.2, 96% men, 39% non-Hispanic white, 26% black/African American, 18% Hispanic/Latino) with comorbid insomnia and newly-diagnosed OSA (apnea-hypopnea index ≥ 15) were randomized to 5-weekly sessions integrating CBTI with a PAP adherence program provided by a "sleep coach" (with behavioral sleep medicine supervision), or 5-weekly sleep education control sessions. Participants and assessment staff were blinded to group assignment. Outcomes (baseline, 3 and 6 months) included Pittsburgh Sleep Quality Index (PSQI), 7-day sleep diary (sleep onset latency [SOL-D], wake after sleep onset [WASO-D], sleep efficiency [SE-D]), 7-day actigraphy (SE-A), and objective PAP use (hours/night and nights ≥ 4 h). Insomnia Severity Index (ISI), Epworth Sleepiness Scale (ESS), and Functional Outcomes of Sleep Questionnaire-10 (FOSQ-10) were also collected.

RESULTS

Compared to controls, intervention participants showed greater improvement (baseline to 3 and 6 months, respectively) in PSQI (-3.2 and -1.7), SOL-D (-16.2 and -15.5 minutes), SE-D (10.5% and 8.5%), SE-A (4.4% and 2.6%) and more 90-day PAP use (1.3 and 0.9 more hours/night, 17.4 and 11.3 more nights PAP ≥ 4 h). 90-day PAP use at 3 months was 3.2 and 1.9 h/night in intervention versus controls. Intervention participants also had greater improvements in ISI, ESS, and FOSQ-10 (all p < 0.05).

CONCLUSIONS

An intervention integrating CBTI with a PAP adherence program delivered by a supervised sleep coach improved sleep and PAP use in adults with comorbid insomnia and OSA.

TRIAL REGISTRATION

ClinicalTrials.govStudy name: Novel Treatment of Comorbid Insomnia and Sleep Apnea in Older VeteransURL: https://clinicaltrials.gov/ct2/results?cond=&term=NCT02027558&cntry=&state=&city=&dist=Registration: NCT02027558.

0696 The O2VERLAP Study: High Cpap Use Levels Found In Overlap Syndrome (OSA And COPD) Patients

Introduction

CPAP therapy is prescribed to help manage disordered breathing during sleep time periods. Most users, especially those with non-severe obstructive sleep apnea (OSA), use it only for some portion of their sleep period. Patients with Overlap Syndrome have both OSA and chronic obstructive pulmonary disease (COPD). While there has been some research on CPAP use levels in this patient population, there has been little indication that they use CPAP any differently than those with OSA only.

Methods

The O2VERLAP Study was a large comparative effectiveness trial enrolling people with COPD and OSA and using two different methods of providing information and support to current users of CPAP therapy. The study utilized an electronic national recruitment strategy and 332 participants were enrolled. CPAP data from the 12-week study period was analyzed. The Pittsburgh Sleep Quality Index was used to determine both estimated total sleep period (TSP) and total sleep time (TST). Because participants were all current users of CPAP, data from the total sample was combined and used. The percentage of TST and TSP that CPAP was used was calculated as CPAP use divided by either TST or TSP.

Results

The mean TST was 6.8 hours, TSP was 8.1 hours, and CPAP use was 6.7 hours. CPAP was used during 98.5% of the TST and during 82.7% of the TSP. Over 35% of the sample used CPAP at a level that was equal to or greater than their total sleep period.

Conclusion

Most OSA study populations use CPAP for some fraction of their night’s sleep. This COPD/OSA study population used CPAP to a markedly high level, including over one-third of the sample (n=~100) who used CPAP more than their self-reported sleep period. Further research on the extent and reasons for non-sleep period (i.e., daytime) CPAP use in COPD patients is warranted.

Support

PPRND #1507-31666.

Indicators of retention in remote digital health studies: a cross-study evaluation of 100,000 participants

Digital technologies such as smartphones are transforming the way scientists conduct biomedical research. Several remotely conducted studies have recruited thousands of participants over a span of a few months allowing researchers to collect real-world data at scale and at a fraction of the cost of traditional research. Unfortunately, remote studies have been hampered by substantial participant attrition, calling into question the representativeness of the collected data including generalizability of outcomes. We report the findings regarding recruitment and retention from eight remote digital health studies conducted between 2014-2019 that provided individual-level study-app usage data from more than 100,000 participants completing nearly 3.5 million remote health evaluations over cumulative participation of 850,000 days. Median participant retention across eight studies varied widely from 2-26 days (median across all studies = 5.5 days). Survival analysis revealed several factors significantly associated with increase in participant retention time, including (i) referral by a clinician to the study (increase of 40 days in median retention time); (ii) compensation for participation (increase of 22 days, 1 study); (iii) having the clinical condition of interest in the study (increase of 7 days compared with controls); and (iv) older age (increase of 4 days). Additionally, four distinct patterns of daily app usage behavior were identified by unsupervised clustering, which were also associated with participant demographics. Most studies were not able to recruit a sample that was representative of the race/ethnicity or geographical diversity of the US. Together these findings can help inform recruitment and retention strategies to enable equitable participation of populations in future digital health research.

Comorbidities, Health-Related Quality of Life, and Work Productivity Among People With Obstructive Sleep Apnea With Excessive Sleepiness: Findings From the 2016 US National Health and Wellness Survey

STUDY OBJECTIVES

Few population-based studies have explored how excessive sleepiness (ES) contributes to burden of illness among patients with obstructive sleep apnea (OSA).

METHODS

This study utilized data from the annual, cross-sectional 2016 US National Health and Wellness Survey. Respondents self-reporting an OSA diagnosis were categorized as having ES (Epworth Sleepiness Scale [ESS] score ≥ 11) or not having ES (ESS score < 11). Comorbidities, health-related quality of life (HRQoL), and productivity were examined in three groups: OSA with ES (n = 731), OSA without ES (n = 1,452), and non-OSA controls (n = 86,961).

RESULTS

The OSA with ES group had significantly higher proportions of respondents reporting depression (62.4% versus 48.0%), gastroesophageal reflux disease (39.0% versus 29.4%), asthma (26.3% versus 20.7%), and angina (7.8% versus 6.7%) compared to the OSA without ES group (P < .05). After controlling for covariates, the OSA with ES group had significantly lower (worse) scores for mental component score (41.81 versus 45.65 versus 47.81), physical component score (46.62 versus 48.68 versus 51.36), and SF-6D (0.65 versus 0.69 versus 0.73) compared with OSA without ES and non-OSA controls (all P < .001). The OSA with ES group had significantly higher (greater burden) mean rates of presenteeism (25.98% impairment versus 19.24% versus 14.75%), work impairment (29.41% versus 21.82% versus 16.85%), and activity impairment (31.09% versus 25.46% versus 19.93%) compared with OSA without ES and non-OSA controls (all P < .01) after controlling for covariates.

CONCLUSIONS

OSA with ES is associated with higher prevalence of comorbidities, reduced HRQoL, and greater impairment in productivity compared to OSA without ES and compared to non-OSA controls.

Recent Advancements in Treating Sleep Disorders in Co-Occurring PTSD

PURPOSE OF REVIEW

Comorbidity of posttraumatic stress disorder (PTSD) and insomnia, nightmares, and obstructive sleep apnea (OSA) is high. We review recent research on psychotherapeutic and pharmacological interventions for sleep disorders in PTSD.

RECENT FINDINGS

PTSD treatments decrease PTSD severity and nightmare frequency, but do not resolve OSA or insomnia. Research on whether insomnia hinders PTSD treatment shows mixed results; untreated OSA does interfere with PTSD treatment. Cognitive behavioral therapy for insomnia is the recommended treatment for insomnia; however, optimal ordering with PTSD treatment is unclear. PTSD treatment may be most useful for PTSD-related nightmares. CPAP therapy is recommended for OSA but adherence can be low. Targeted treatment of sleep disorders in the context of PTSD offers a unique and underutilized opportunity to advance clinical care and research. Research is needed to create screening protocols, determine optimal order of treatment, and elucidate mechanisms between sleep and PTSD treatments.

CPAP Adherence is Associated With Attentional Improvements in a Group of Primarily Male Patients With Moderate to Severe OSA

STUDY OBJECTIVES

Obstructive sleep apnea (OSA) is a widespread condition that adversely affects physical health and cognitive functioning. The prevailing treatment for OSA is continuous positive airway pressure (CPAP), but therapeutic benefits are dependent on consistent use. Our goal was to investigate the relationship between CPAP adherence and measures of sustained attention in patients with OSA. Our hypothesis was that the Psychomotor Vigilance Task (PVT) would be sensitive to attention-related improvements resulting from CPAP use.

METHODS

This study was a secondary analysis of a larger clinical trial. Treatment adherence was determined from CPAP use data. Validated sleep-related questionnaires and a sustained-attention and alertness test (PVT) were administered to participants at baseline and at the 6-month time point.

RESULTS

Over a 6-month time period, the average CPAP adherence was 3.32 h/night (standard deviation [SD] = 2.53), average improvement in PVT minor lapses was -4.77 (SD = 13.2), and average improvement in PVT reaction time was -73.1 milliseconds (standard deviation = 211). Multiple linear regression analysis showed that higher CPAP adherence was significantly associated with a greater reduction in minor lapses in attention after 6 months of continuous treatment with CPAP therapy (β = -0.72, standard error = 0.34, P = .037).

CONCLUSIONS

The results of this study showed that higher levels of CPAP adherence were associated with significant improvements in vigilance. Because the PVT is a performance-based measure that is not influenced by prior learning and is not subjective, it may be an important supplement to patient self-reported assessments.

CLINICAL TRIAL REGISTRATION

Name: Effect of Self-Management on Improving Sleep Apnea Outcomes, URL: https://clinicaltrials.gov/ct2/show/NCT00310310, Identifier: NCT00310310.

Treatment of OSA with CPAP Is Associated with Improvement in PTSD Symptoms among Veterans

STUDY OBJECTIVES

Posttraumatic stress disorder (PTSD) is common among veterans of the military, with sleep disturbance as a hallmark manifestation. A growing body of research has suggested a link between obstructive sleep apnea and PTSD, potentially due to obstructive sleep apnea (OSA) related sleep disruption, or via other mechanisms. We examined the hypothesis that treatment of OSA with positive airway pressure would reduce PTSD symptoms over 6 months.

METHODS

A prospective study of Veterans with confirmed PTSD and new diagnosis of OSA not yet using PAP therapy were recruited from a Veteran's Affairs sleep medicine clinic. All subjects were instructed to use PAP each night. Assessments were performed at 3 and 6 months. The primary outcome was a reduction in PTSD symptoms at 6 months.

RESULTS

Fifty-nine subjects were enrolled; 32 remained in the study at 6 months. A significant reduction in PTSD symptoms, measured by PCL-S score was observed over the course of the study (60.6 ± 2.7 versus 52.3 ± 3.2 points; p < 0.001). Improvement was also seen in measures of sleepiness, sleep quality, and daytime functioning, as well as depression and quality of life. Percentage of nights in which PAP was used, but not mean hours used per night, was predictive of improvement.

CONCLUSIONS

Treatment of OSA with PAP therapy is associated with improvement in PTSD symptoms, although the mechanism is unclear. Nonetheless, PAP should be considered an important component of PTSD treatment for those with concurrent OSA. Improving PAP compliance is a challenge in this patient population warranting further investigation.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov, ID: NCT02019914.

COMMENTARY

A commentary on this article appears in this issue on page 5.

Ethical responsibilities toward indirect and collateral participants in pragmatic clinical trials

Pragmatic clinical trials are designed to inform decision makers about the benefits, burdens, and risks of health interventions in real-world settings. Pragmatic clinical trials often use for research purposes data collected in the course of clinical practice. The distinctive features of pragmatic clinical trials demand fresh thinking about what is required to act properly toward people affected by their conduct, in ways that go beyond ensuring the protection of rights and welfare for "human research subjects" under conventional research ethics regulations. To stimulate such work, we propose to distinguish among categories of research participants in pragmatic clinical trials as follows: Direct participants: (1) individuals being directly intervened upon and/or (2) individuals from whom personal identifiable data are being collected for the purposes of the pragmatic clinical trial. Indirect participants: individuals who are (1) not identified as direct participants and (2) whose rights and welfare may be affected by the intervention through their routine exposure to the environment in which the intervention is being deployed. Collateral participants: patient groups and other stakeholder communities who may be otherwise affected by the occurrence and findings of the pragmatic clinical trial. We illustrate these distinctions with case examples and discuss the distinctive responsibilities of researchers and pragmatic clinical trial leadership toward each type of participant. We suggest that pragmatic clinical trial investigators, institutional review boards, health systems leaders, and others engaged in the research enterprise work together to identify these participants. For indirect participants, risks and benefits to which they are exposed should be weighed to ensure that their rights and welfare are protected accordingly, and communication strategies should be considered to help them make well-informed decisions. Collateral participants could provide input on the design, planning, and conduct of a pragmatic clinical trial and offer insights regarding the best way to communicate the trial's results to their constituencies.

The state of Veterans Affairs sleep medicine programs: 2012 inventory results

PURPOSE

The Veterans Health Administration (VHA) represents one of the largest integrated health-care systems in the country. In 2012, the Veterans Affairs Sleep Network (VASN) sought to identify available sleep resources at VA medical centers (VAMCs) across the country through a national sleep inventory.

METHODS

The sleep inventory was administered at the annual 2012 VA Sleep Practitioners meeting and by email to sleep contacts at each VAMC. National prosthetics contacts were used to identify personnel at VAMCs without established sleep programs. Follow-up emails and telephone calls were made through March 2013.

RESULTS

One hundred eleven VA medical centers were included for analysis. Thirty-nine programs did not respond, and 10 were considered "satellites," referring all sleep services to a larger neighboring VAMC. Sleep programs were stratified based on extent of services offered (i.e., in-lab and home testing, sleep specialty clinics, cognitive behavioral therapy for insomnia (CBT-i)): 28 % were complex sleep programs (CSPs), 46 % were intermediate (ISPs), 9 % were standard (SSPs), and 17 % offered no formal sleep services. Overall, 138,175 clinic visits and 90,904 sleep testing encounters were provided in fiscal year 2011 by 112.1 physicians and clinical psychologists, 100.4 sleep technologists, and 115.3 respiratory therapists. More than half of all programs had home testing and CBT-i programs, and 26 % utilized sleep telehealth.

CONCLUSIONS

The 2012 VA sleep inventory suggests considerable variability in sleep services within the VA. Demand for sleep services is high, with programs using home testing, sleep telehealth, and a growing number of mid-level providers to improve access to care.

Does Positive Airway Pressure Therapy Result in Improved Sleep Quality?

INTRODUCTION

Positive airway pressure (PAP) therapy is the gold-standard for obstructive sleep apnea (OSA) management. While it is known that PAP is efficacious for controlling breathing events during sleep when it is worn at the right pressure for the amount of time prescribed, there is less clear data on how well it improves sleep quality. There are few studies that have examined the effectiveness of PAP therapy on sleep quality.

METHODS

OSA participants (n = 241) from a larger trial examining a PAP adherence were included. Participants were provided with PAP instruction and followed at 2 months and 4 months. PAP adherence was measured as the number of hours per night at prescribed pressure, an objective measure of treatment adherence. The Pittsburgh Sleep Quality Index (PSQI) was used as the primary measure of sleep quality.

RESULTS

The PSQI was significantly correlated with PAP adherence at both the 2-month and 4-month time points, such that lower sleep quality was associated with lower PAP use. This finding held for the sleep disturbance subscale of the PSQI. Over 55% of those using PAP therapy at the 4-month time point continued to report significantly disturbed sleep.

DISCUSSION

This study shows that PAP therapy does not appear to improve sleep quality to a degree that would be expected. Over half of those patients using PAP therapy still experienced disturbed sleep. Whether the disturbed sleep is directly attributable to the PAP device itself or to disturbed sleep secondary to uncontrolled OSA when PAP is not worn is worthy of further investigation.

Sleep in older African Americans and Caucasians at risk for sleep-disordered breathing

This study explored differences in sleep between older African Americans (AA) and Caucasians (CA) at risk for sleep-disordered breathing. Seventy AA and 70 CA were compared on ambulatory monitoring sleep variables and on self-reports on health and socioeconomic status (SES). After controlling for SES and health covariates, CA woke up significantly more often than AA (p = .018), but there were no other differences in sleep variables between the two groups. Time awake at night was related to being male, more depression, less walking, and lower income, whereas having more awakenings during the night was related to being CA, higher apnea-hypopnea index, and higher periodic leg movement index. Importance of inclusion of SES, health, and other covariates in studies exploring racial differences in sleep are discussed.

Adherence to continuous positive airway pressure treatment in patients with Alzheimer's disease and obstructive sleep apnea

OBJECTIVE

This analysis examined whether patients with Alzheimer disease (AD) tolerate continuous positive airway pressure (CPAP).

METHOD

Thirty patients with AD were randomized to CPAP or sham CPAP and completed sleep, depression, and quality-of-life questionnaires. Participants could choose to continue treatment after the trial.

RESULTS

Patients wore CPAP for 4.8 hours per night. More depressive symptoms were associated with worse adherence (rS=-0.37; N=30, p<0.04). Patients who continued using CPAP had fewer depressive symptoms (t [19]=2.45, p=0.02) and better adherence (t [19]=2.32, p=0.03) during the trial.

CONCLUSION

Patients with AD with obstructive sleep apnea can tolerate CPAP. Adherence and long-term use may be more difficult among those patients with more depressive symptoms.

Shortening the feedback loop for sleep apnea patients via a wireless blood pulse-oximetry system

Much of the clinical care of sleep apnea patients is focused on case identification, diagnosis, and treatment prescription, while follow-up care tends to be intermittent and patient-initiated. There is a clear need for an alternative, cost-effective way to examine sleep apnea treatment efficacy. As part of our research program to improve the clinical care of sleep apnea patients using Internet enabled systems, we have developed a prototype Wireless Blood Pulse-Oximeter System that patients can use in their homes. The oximeter system can be applied by the patient and is based on a data-push mechanism to a secure server that is designed for both patient and provider access.

Comparing night-to-night variability of sleep measures in elderly African Americans and Whites

There has been great interest in the night-to-night variability of sleep-disordered breathing because of the implications for the accuracy and costs associated with diagnostic testing. Night-to-night variability of sleep and respiratory parameters were examined in 66 older Whites and 56 older African Americans. Each participant had his or her sleep recorded for 2 nights with portable recording equipment. The correlations between the 2 nights were all large. Analyses of variance showed that men had a greater change in apnea index and in number of apneas than women. There were no differences in the parameters for African Americans versus Whites. One night of sleep recording may be sufficient for studying sleep disorders in elderly persons.

Predicting treatment adherence in obstructive sleep apnea using principles of behavior change

STUDY OBJECTIVES

To determine the relative predictive utility of measures of behavior-change principles on treatment adherence in individuals with obstructive sleep apnea.

METHODS

Ninety-eight participants with moderate to severe obstructive sleep apnea were recruited into this prospective longitudinal study. Participants were recruited from an academic sleep disorders center after having completed in-lab polysomnography and before initiating continuous positive airway pressure (CPAP) therapy. Participants were all treatment naive. Measurements of behavior-change principles were taken at baseline and periodically throughout the 6-month follow-up. Adherence, measured by the amount of nightly use at the proper pressure, was monitored covertly by the CPAP machines.

RESULTS

Measures from 2 behavior-change theories (Transtheoretical Model and Social Cognitive Theory) were used in this study: readiness to change, perceived self-efficacy, and decisional balance. The results from the present study suggest that measures of behavior change predict CPAP adherence at 6 months posttreatment when assessed at 1 week and at 3 months posttreatment. When these measures are assessed at baseline, however, they are not predictive of CPAP use at 6-months. These measures do not improve upon the prediction of 6-month adherence provided by previous adherence.

CONCLUSIONS

While the readiness, decisional balance, and self-efficacy measures were all predictive of adherence, the strongest predictive utility came from measures of readiness and self-efficacy. Those individuals who use CPAP more were more likely to rate themselves as ready and confident in their ability to use CPAP. The utility of these measures was diminished when controlling for previous use. Our intention, however, was to study modifiable risk factors for poor adherence. Principles of behavior change, which are often used in adherence research in other medical populations, are thought to be modifiable with behavioral interventions and show promise for improving adherence.

Cognitive changes and sleep disordered breathing in elderly: differences in race

OBJECTIVES

Sleep disordered breathing (SDB) is a highly prevalent sleep disorder in older persons. It is known to be associated with reductions in cognitive function. As part of a larger study examining SDB in African-Americans and Caucasians, it became possible to examine whether racial background may differentially affect the relationship between SDB and cognitive performance.

METHODS

Community-dwelling African-American and Caucasian elderly (ages 65+) at high risk for SDB were tested at two time points. During each visit, subjects were interviewed in their homes about their sleep and medical condition. The Mini-Mental Status Examination (MMSE) was used to assess cognitive function. Objective sleep studies were recorded in the subjects' homes and scored for sleep, apneic events, and oxygen saturation levels.

RESULTS

Increases in respiratory disturbance index (RDI) were associated with decreases in cognitive performance over time, after controlling for gender and education level. There were no differential effects of race on this relationship. There was no relationship between declining cognitive function and hypoxemia.

CONCLUSIONS

Analyses of the data confirm that declining cognitive function in older persons with mild to moderate SDB is related to the amount of respiratory disturbances occurring at night, and suggest that the effect of SDB on cognitive decline is unrelated to race and measured hypoxemia. The large number of community-dwelling elderly with mild to moderate SDB may accrue considerable benefits (both cognitively and medically) from the treatment of SDB, even if they are not markedly hypoxemic.

The Relationship Between Congestive Heart Failure, Sleep Apnea, and Mortality in Older Men

STUDY OBJECTIVES

To examine the association of sleep apnea with heart disease.

DESIGN

Prospective study.

SETTING

Medical wards at the Veterans Affairs San Diego Healthcare System.

PATIENTS

Three hundred fifty-three randomly selected inpatient men.

MEASUREMENTS AND RESULTS

Sleep was recorded for 2 nights in the hospital. Medical conditions were obtained from hospital medical records. Cox proportional hazards analyses indicated that patients with congestive heart failure (CHF) plus central sleep apnea (CSA) had shorter survival than those with just CHF, just sleep apnea (obstructive or central), or neither. Survival for those with obstructive sleep apnea (OSA) or CSA and no CHF was no different than for those with neither disorder. Follow-up analysis showed that for those with no CHF, neither CSA nor OSA shortened survival (p > 0.80). For those with CHF, having CSA shortened the life span with a hazard ratio of 1.66 (p = 0.012), but having OSA had no effect. Patients with CHF had more severe sleep apnea than those with no heart disease.

CONCLUSIONS

This study does not clarify the issues of cause and effect, but does reinforce the strong associations between sleep apnea and heart disease in elderly men. These data suggest that people with coronary disease should be regarded as a risk group for sleep apnea.

The effect of race and sleep-disordered breathing on nocturnal BP "dipping": analysis in an older population

STUDY OBJECTIVES

BP normally drops (or "dips") by approximately 10% at nighttime; however, in a number of illnesses there is an increased amount of "nondipping" of nocturnal BP. This study examined whether nondipping in older African Americans and older white subjects is related to the presence of sleep-disordered breathing (SDB) and hypertension.

DESIGN

Prospective study with a convenience sample.

SETTING

All data were collected in the subjects' homes.

PARTICIPANTS

Seventy self-defined African Americans with complaints of snoring or excessive daytime sleepiness, and 70 age-matched and gender-matched white subjects.

MEASUREMENTS AND RESULTS

Sleep was recorded for 2 nights, with 1 night of oximetry. BP was recorded on a separate 24-h period. African Americans had higher dipping ratios than white subjects even after accounting for covariates such as respiratory disturbance index (RDI), oxygen desaturation index (ODI), body mass index, and average 24-h mean arterial pressure (p = 0.025). Higher values of RDI (R(2) = 0.0686, p = 0.021) and ODI (R(2) = 0.042, p < 0.03) were correlated with higher dipping ratios in both African Americans and white subjects. However, there was a three-way interaction such that higher RDIs were correlated primarily with nondipping in African Americans receiving antihypertensive medication (R(2) = 0.0373, p = 0.022).

CONCLUSIONS

These results demonstrated that African Americans tend to be "nondippers," while white subjects tended to be "dippers." This nondipping was not a result of weight, gender, or of having SDB. The analyses also confirmed that, in both races, the dipping ratio was greatest in those with SDB and hypertension. The third hypothesis, that RDI would be greatest in the nondipping hypertensive subjects, was true only for the African Americans.

Long-term follow-up of periodic limb movements in sleep in older adults

STUDY OBJECTIVES

The goal of this study was to examine the natural history of periodic limb movements in sleep (PLMS) in older adults.

DESIGN

Prospective, longitudinal design.

SETTING

San Diego area.

PARTICIPANTS

Community-dwelling older adults.

INTERVENTIONS

NA MEASUREMENTS AND RESULTS: Subjects participated in follow-up visits every few years. Sleep disorders were assessed at each visit using sleep questionnaires and overnight sleep recordings. Changes in PLMS over time were examined as well as variables that were associated with change. Average PLMS did not change over time, although there was considerable variability within the sample. In women, changes in PLMS were associated with changes in sleep-disordered breathing. This relationship was not found in men.

CONCLUSIONS

Although the prevalence of PLMS is high for older adults, the severity of the disorder does not progressively worsen with increasing age.

Changes in cognitive function associated with sleep disordered breathing in older people

OBJECTIVES

Sleep disordered breathing (SDB) is very common in older people and is known to be associated with complaints of impaired daily functioning, including excessive daytime sleepiness and cognitive impairments. As part of a larger study on SDB and aging, it became possible to examine the relationship between SDB and cognition in older men and women.

DESIGN

A population-based longitudinal study.

SETTING

In-home interviews and home sleep recordings in the greater San Diego area.

PARTICIPANTS

Community-dwelling people age 65 and older with high risk for SDB were originally studied from 1981 through 1985 and then followed every 2 years. Data from the 46 subjects who completed Visit 3 and Visit 4 are presented.

MEASUREMENTS

Subjects were interviewed in the home about their sleep and medical condition before each visit. Cognitive function was assessed using the Mini-Mental State Examination (MMSE). Daytime sleepiness was based on self-report. Objective sleep was recorded in the home and scored for sleep, apneas and hypopneas, and oximetry variables.

RESULTS

Increases in respiratory disturbance index (RDI) (P= .036) and increases in daytime sleepiness (P= .002) were associated with decreases in cognitive performance (i.e., increases in cognitive impairment). Increases in RDI were also associated with increases in daytime sleepiness (P= .012). Change in MMSE scores was therefore regressed onto changes in RDI, daytime sleepiness, age, and education, resulting in decreases in MMSE scores being associated with increases in daytime sleepiness (P= .019) but not with changes in RDI (P= .515). There was no significant relationship between changes in oxygen saturation levels and changes in MMSE.

CONCLUSIONS

The results of this study suggest that declining cognitive function is associated primarily with increases in daytime sleepiness. Although cognitive decline was also associated with increases in RDI, this association did not hold in the more inclusive model which also included variable of SDB, oximetry, sleep and subjective report. One theoretical model could suggest that any relationship between SDB and cognitive function may be mediated by the effect of SDB on daytime sleepiness. These results suggest that older patients suffering from mild to moderate SDB may benefit from the treatment of SDB, even if they are not markedly hypoxemic.

Long-term follow-up of sleep disordered breathing in older adults

OBJECTIVE

The current study was designed to determine whether, with increasing age, sleep apnea improves, becomes worse, or stays the same.

BACKGROUND

There is a high prevalence of sleep disordered breathing (SDB) in older adults, but little is known about longitudinal changes. This study followed older adults to examine the natural history of SDB.

METHODS

Subjects were randomly selected community-dwelling elderly (n=427). A subset of subjects was studied approximately every 2 years over an 18-year period. Overnight sleep recordings and sleep questionnaires were completed at each time point.

RESULTS

Multiple linear regression showed that three variables were associated with change in respiratory disturbance index (RDI):body mass index (BMI) at initial visit (P=0.001), change in BMI (P=0.02), and a consistent self-report of high blood pressure (P=0.005). RDI increase was associated with BMI increase and presence of self-reported high blood pressure.

CONCLUSIONS

The changes in RDI that occurred were associated only with changes in BMI and were independent of age. This underscores the importance of managing weight for older adults, particularly those with hypertension.

Sleep apnea and health-related quality of life in African-American elderly

The relationship between health-related quality of life (HRQOL) and sleep apnea was examined in a sample of elderly African-Americans screened for snoring and daytime sleepiness. Seventy African-Americans over the age of 65 years completed a comprehensive sleep questionnaire, the Quality of Well-Being Scale (QWB), and the Medical Outcomes Study (MOS) Core Measures of HRQOL (116-item Long Version) and had sleep recorded. Those with moderate-severe sleep apnea had significantly lower Physical Component summary scores than those with no sleep apnea (p < 0.05). After controlling for medical conditions, sleep apnea was significantly related to both general physical functioning and general mental health functioning in those with mild apnea (apnea-hypopnea index [AHI] < 15), but not in those with moderate to severe apnea. There was an initial decrease in HRQOL up to an AHI level of 15, at which point HRQOL remained at a lowered level. The QWB scores of our sleep apnea sample were similar to the QWB scores found in patients with depression and chronic obstructive pulmonary disease (COPD), suggesting that sleep disturbances may impact daily living and health as much as other medical conditions.

Identification and treatment of sleep problems in the elderly

For many adults, changes in sleep occur with aging. An estimated 15 million elderly, or 50% of older Americans, experience some sleep problem. The elderly complain that their sleep is more fragmented and that as they have gotten older, they experience more daytime sleepiness. Laboratory studies have confirmed these complaints. Research has shown that it is not the need for sleep that decreases with age, but rather the ability to sleep. Circadian rhythm disturbances, sleep disorders such as sleep disordered breathing and periodic movements in sleep, medical illness, medication use, and impaired cognitive functioning all contribute to poor sleep and decreased daytime alertness. In institutionalized elderly, sleep is even more disturbed and disrupted. With careful assessment, many of these problems can be addressed and treated, and sometimes cured.

Evaluation of sleep disordered breathing with unattended recording: the Nightwatch System

There is a need for studies to determine how new ambulatory systems compare to traditional polysomnography (PSG). Thirty-four subjects were recorded with the Nightwatch (NW) System (Heathdyne Inc.) at home and then recorded with PSG in the laboratory. NW records were scored automatically using the NW algorithm with manual editing. There were no significant differences in mean RDI, AI, number of apneas or hypopneas or oximetry varibles between the systems. Correlations of RDI on the Nightwatch system and laboratory nights were significant (r = 0.63). Every case of RDI > or = 10 on the PSG was also identified by Nightwatch. Specificity was lower on Nightwatch (66%); however, all three cases of false positives could be explained physiologically, i.e. by body position. Overall the NW system correlated well with traditional PSG for respiratory disturbance.

Morbidity, mortality and sleep-disordered breathing in community dwelling elderly

A population-based probability sample of elderly individuals (n = 426), who were originally studied between 1981 and 1986 (mean age at initial study was 72.5 years), were followed for mortality. Those with > or = 30 respiratory disturbances per hour of sleep had significantly shorter survival (p = 0.0034), but the respiratory disturbance index (RDI) was not an independent predictor of death. When Cox proportional hazards analysis was done, only age (the strongest predictor), cardiovascular disease and pulmonary disease were independent predictors of death. It may be that factors that are secondary to or associated with sleep-disordered breathing (SDB), such as cardiovascular or pulmonary disease, predispose these elderly to death.

Sleep-disordered breathing in African-American elderly

Although sleep-disordered breathing (SDB) has been shown to be very prevalent in the elderly, little has been done to examine differences between the elderly of different racial groups. It has been well documented that SDB often results in hypertension and that hypertension is more common in African-Americans than in Caucasians. Therefore, one might suspect that SDB might be more common in African-Americans. Caucasians (n = 346) and African-Americans (n = 54) older than 65 yr of age were studied. African-Americans reported less satisfaction with sleep (p = 0.017), more difficulty falling asleep (p < 0.001), more daytime sleepiness (p = 0.0014), and more frequent morning headaches (p = 0.0043). African-Americans napped 0.8 times more frequently per evening (p = 0.05) and 11 min longer per nap (p = 0.019) than did Caucasians, and they showed a trend toward more total sleep time (428 versus 408 min). Of greater interest was the fact that more African-Americans had severe SDB with a relative risk twofold as great (relative risk = 2.13) as that for Caucasians, which was confirmed in a logistic regression analysis where race was associated with the presence of SDB (RDI > or = 30) independently of age, sex, and body mass index. The mean RDI for those African-Americans with severe SDB was significantly higher than that for Caucasians (72.1 versus 43.3; p = 0.014).

Natural history of sleep disordered breathing in community dwelling elderly

Mild sleep disordered breathing is very common in the elderly, but little is known about the course of the disorder over time. Twenty-four elderly people from a population-based study were recorded three times over an 8.5-year period. There were no significant changes in either apnea index or in respiratory disturbance index (RDI) over time, even when controlled for body mass index. For most subjects, there was great variability over time in the number of respiratory disturbances. The sensitivity of RDI > or = 15 at visit 1 predicting RDI > or = 15 at visit 3 was only 20%. The predictive value was 50%. Sleep disordered breathing measured at a single point in time is rather weakly predictive of the severity of breathing disorder 4-8 years later.