Development, Validation, and Assessment of an Ischemic Stroke or Transient Ischemic Attack-Specific Prediction Tool for Obstructive Sleep Apnea.

BACKGROUND: Screening instruments for obstructive sleep apnea (OSA), as used routinely to guide clinicians regarding patient referral for polysomnography (PSG), rely heavily on symptomatology. We sought to develop and validate a cerebrovascular disease-specific OSA prediction model less reliant on symptomatology, and to compare its performance with commonly used screening instruments within a population with ischemic stroke or transient ischemic attack (TIA). METHODS: Using data on demographic factors, anthropometric measurements, medical history, stroke severity, sleep questionnaires, and PSG from 2 independently derived, multisite, randomized trials that enrolled patients with stroke or TIA, we developed and validated a model to predict the presence of OSA (i.e., Apnea-Hypopnea Index ≥5 events per hour). Model performance was compared with that of the Berlin Questionnaire, Epworth Sleepiness Scale (ESS), the Snoring, Tiredness, Observed apnea, high blood Pressure, Body mass index, Age, Neck circumference, and Gender instrument, and the Sleep Apnea Clinical Score. RESULTS: The new SLEEP Inventory (Sex, Left heart failure, ESS, Enlarged neck, weight [in Pounds], Insulin resistance/diabetes, and National Institutes of Health Stroke Scale) performed modestly better than other instruments in identifying patients with OSA, showing reasonable discrimination in the development (c-statistic .732) and validation (c-statistic .731) study populations, and having the highest negative predictive value of all in struments. CONCLUSIONS: Clinicians should be aware of these limitations in OSA screening instruments when making decisions about referral for PSG. The high negative predictive value of the SLEEP INventory may be useful in determining and prioritizing patients with stroke or TIA least in need of overnight PSG.

Asthma-COPD overlap syndrome in the US: a prospective population-based analysis of patient-reported outcomes and health care utilization.

BACKGROUND: Prior work suggests that asthma-COPD overlap syndrome (ACOS) has a greater health burden than asthma alone or COPD alone. In the current study, we have further evaluated the health burden of ACOS in a nationally representative sample of the US population, focusing on patient-reported outcomes and health care utilization and on comparisons with asthma alone and COPD alone. Patient-reported outcomes are especially meaningful, as these include functional activities that are highly valued by patients and are the basis for patient-centered care. METHODS: Using data from the Medical Expenditure Panel Survey (MEPS), we evaluated patient-reported outcomes and health care utilization among participants who were aged 40-85 years and had self-reported, physician-diagnosed asthma or COPD. MEPS administered five rounds of interviews, at baseline and approximately every 6 months over 2.5 years. Patient-reported outcomes included activities of daily living (ADLs), mobility, social/recreational activities, disability days in bed, and health status (Short Form 12, Version 2). Health care utilization included outpatient and emergency department (ED) visits, and hospitalization. RESULTS: Of 3,486 participants with asthma or COPD, 1,585 (45.4%) had asthma alone, 1,294 (37.1%) had COPD alone, and 607 (17.4%) had ACOS. Relative to asthma alone, ACOS was significantly associated with higher odds of prevalent disability in ADLs and limitations in mobility and social/recreational activities (adjusted odds ratios [adjORs]: 1.91-3.98), as well as with higher odds of incident limitations in mobility and social/recreational activities, disability days in bed, and respiratory-based outpatient and ED visits, and hospitalization (adjORs: 1.86-2.35). In addition, ACOS had significantly worse physical and mental health scores than asthma alone (P-values <0.0001). Relative to COPD alone, ACOS was significantly associated with higher odds of prevalent limitations in mobility and social/recreational activities (adjORs: 1.68-2.06), as well as with higher odds of incident disability days in bed and respiratory-based outpatient and ED visits (adjORs: 1.48-1.74). In addition, ACOS had a significantly worse physical health score, but similar mental health score, as compared with COPD alone (P-values 0.0025 and 0.1578, respectively). CONCLUSION: In the US, ACOS is associated with a greater health burden, including patient-reported outcomes and health care utilization, relative to asthma alone and COPD alone.

Aging-Related Considerations When Evaluating the Forced Expiratory Volume in 1 Second (FEV1) Over Time.

BACKGROUND: Forced expiratory volume in 1 second (FEV1) over time is commonly expressed in liters and percent predicted (%Pred), or alternatively in L/m(3) and Z-scores-which approach is more clinically meaningful has not been evaluated. Because it uniquely accounts for the effect of aging on FEV1 and spirometric performance, we hypothesized that the Z-score approach is more clinically meaningful, based on associations between cardiopulmonary predictors and FEV1 over time. METHODS: Using linear mixed-effects models and data from the Baltimore Longitudinal Study on Aging, including 501 white participants aged 40-95 who had completed at least three longitudinal spirometric assessments, we evaluated the associations between cardiopulmonary predictors (obesity, smoking status, hypertension, chronic bronchitis, diabetes mellitus, and myocardial infarction) and FEV1 over time, in liters, %Pred, L/m(3), and Z-scores. RESULTS: Mean baseline values for FEV1 were 3.240L, 96.4%Pred, 0.621L/m(3), and -0.239 as a Z-score (40.6th percentile). The annual decline in FEV1 was 0.040L, 0.234 %Pred, 0.007L/m(3), and 0.008 Z-score units. Baseline age was associated with FEV1 over time in liters and L/m(3) (p < .001), and included a time interaction for %Pred (p < .001), but was not associated with Z-scores (p = .933). The associations of cardiopulmonary predictors with FEV1 over time were all significant when using Z-scores (p < .05), but varied for other methods of expressing FEV1. CONCLUSION: A Z-score approach is more clinically meaningful when evaluating FEV1 over time, as it accounted for the effect of aging and was more frequently associated with multiple cardiopulmonary predictors.

Diagnosis and Treatment of Sleep Apnea in patients' homes: the rationale and methods of the "GoToSleep" randomized-controlled trial.

BACKGROUND: The "Diagnosis and Treatment of Sleep Apnea in Cerebrovascular Disease" (GoToSleep) study is evaluating a strategy to improve the diagnosis and treatment of sleep apnea among veterans with stroke or transient ischemic attack (TIA) who also have hypertension. Specifically, the GoToSleep study was designed to overcome some of the barriers that exist within the Veterans Health Administration (VHA) to the timely diagnosis and treatment of sleep apnea by using ambulatory home-based polysomnography and auto-titrating continuous positive airway pressure (CPAP) to reduce the reliance on laboratory-based sleep studies. METHODS: The GoToSleep study is a prospective, multi-site, randomized, controlled strategy trial among an expected 318 veterans with cerebrovascular disease and hypertension who are assigned to an intervention group or a control group. Patients in the intervention group receive unattended polysomnography at baseline, and those with sleep apnea receive auto-titrating CPAP therapy for up to one year. Patients in the control group receive usual care and unattended polysomnography at the end of the study to identify the rate of undiagnosed sleep apnea. The primary objectives of the GoToSleep study are to determine whether a diagnostic and therapeutic intervention strategy among veterans with cerebrovascular disease and hypertension improves: (1) detection of sleep apnea; (2) appropriate treatment for sleep apnea; and (3) control of hypertension. Twenty-four-hour blood pressure assessments are made at baseline and at the end of the one-year study period for both groups. Antihypertensive medications and their doses are recorded at the time of the 24-hour blood pressure measurements. DISCUSSION: This manuscript provides the rationale for 4 key components of the design of the GoToSleep trial: the inclusion of patients with cerebrovascular disease and hypertension without the use of a measure of daytime sleepiness as an eligibility criterion; the use of portable polysomnography and auto-titrating CPAP in patients' homes rather than using sleep laboratory polysomnography with fixed pressure CPAP; the analytic approach to evaluating change in blood pressure in the context of change in antihypertensive medications; and the use of a usual care control group.