Impact of wait times for treatment on clinical outcomes in patients with obstructive sleep apnoea: protocol for a randomised controlled trial.

Background: Obstructive sleep apnoea (OSA) is a common chronic condition that is associated with significant morbidity and economic cost. Prolonged wait times are increasingly being recognised as a barrier to diagnosis and treatment of many chronic diseases; however, no study to date has prospectively evaluated the impact of wait times on health outcomes in OSA.

Objective: The purpose of this study is to determine whether treatment outcomes for individuals with OSA differ between patients managed using an expedited standard pathway.

Optimizing COPD Acute Care Patient Outcomes Using a Standardized Transition Bundle and Care Coordinator: A Randomized Clinical Trial.

Background: Acute exacerbations of COPD (AECOPD) are associated with high morbidity and mortality and frequent readmissions.

Research Question: What is the effectiveness of a COPD transition bundle, with and without a care coordinator, on rehospitalizations and ED revisits?

Study Design And Methods: Two patient cohorts were selected: (1) the group exposed to the transition bundle and (2) the group not exposed to the transition bundle (usual care group). Patients exposed subsequently were randomized to a care coordinator.

Treatment outcomes among rural and urban patients with obstructive sleep apnea: a prospective cohort study.

Study Objectives: To determine whether adherence to continuous positive airway pressure (CPAP) in adults with uncomplicated obstructive sleep apnea differs by rural vs urban residential address.

Methods: In this prospective cohort study, we recruited adults who initiated CPAP for uncomplicated obstructive sleep apnea that was diagnosed by a physician using sleep specialist-interpreted diagnostic testing. Participants were classified as urban (community size > 100,000) or rural (community size < 100,000) by translating residential postal code into geographic census area.

An evaluation of rural-urban disparities in treatment outcomes for obstructive sleep apnoea: study protocol for a prospective cohort study.

Background: Obstructive sleep apnoea (OSA) is a common and treatable chronic condition that is associated with significant morbidity and economic cost. Geography is increasingly being recognised as a barrier to diagnosis and treatment of many chronic diseases; however, no study to date has investigated the impact of place of residence on health outcomes in OSA.

Objective: The purpose of this study is to determine whether treatment outcomes for patients initiating continuous positive airway pressure (CPAP) for OSA differ between those who live in urban rural settings.

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.

Predicting CPAP failure in patients with suspected sleep hypoventilation identified on ambulatory testing.

Study Objectives: Home sleep apnea testing (HSAT) is commonly used to diagnose obstructive sleep apnea, but its role in identifying patients with suspected hypoventilation or predicting their response to continuous positive airway pressure (CPAP) therapy has not been assessed. The primary objective was to determine if HSAT, combined with clinical variables, could predict the failure of CPAP to correct nocturnal hypoxemia during polysomnography in a population with suspected hypoventilation. Secondary objectives were to determine if HSAT and clinical parameters could predict awake or sleep hypoventilation.

Functional-Optical Coherence Tomography: A Non-invasive Approach to Assess the Sympathetic Nervous System and Intrinsic Vascular Regulation.

Sympathetic nervous system dysregulation and vascular impairment in neuronal tissue beds are hallmarks of prominent cardiorespiratory diseases. However, an accurate and convenient method of assessing SNA and local vascular regulation is lacking, hindering routine clinical and research assessments. To address this, we investigated whether spectral domain optical coherence tomography (OCT), that allows investigation of retina and choroid vascular responsiveness, reflects sympathetic activity in order to develop a quick, easy and non-invasive sympathetic index.

A Randomized Controlled Trial of an Alternative Care Provider Clinic for Severe Sleep-disordered Breathing.

Lack of timely access to diagnosis and treatment of sleep-disordered breathing (SDB) has sparked interest in using nonphysician providers. Previous studies of these alternative care providers (ACPs) excluded patients with more complicated forms of SDB and did not directly explore the impacts of a model incorporating ACPs on healthcare system performance, such as wait times. To evaluate the use of ACPs in the management of patients with severe SDB from a clinical and system perspective.

Identifying Cases of Sleep Disorders through International Classification of Diseases (ICD) Codes in Administrative Data.

Objectives: Prevalence, and associated morbidity and mortality of chronic sleep disorders have been limited to small cohort studies, however, administrative data may be used to provide representation of larger population estimates of disease. With no guidelines to inform the identification of cases of sleep disorders in administrative data, the objective of this study was to develop and validate a set of ICD-codes used to define sleep disorders including narcolepsy, insomnia, and obstructive sleep apnea (OSA) in administrative data.

Methods: A cohort of adult patients, with medical records reviewed by two independent board-certified sleep physicians from a sleep clinic in Calgary, Alberta between January 1, 2009 and December 31, 2011, was used as the reference standard.

Validity of administrative data for identification of obstructive sleep apnea.

Obstructive sleep apnea (OSA) is a common condition associated with significant morbidity and health-care utilization. We determined the validity of an algorithm derived from administrative data for identifying OSA using the respiratory disturbance index (RDI) as the reference standard. We conducted a retrospective cohort study of adults in Alberta, Canada referred for facility and community-based sleep diagnostic testing between July 2005 and August 2007.

Birt-Hogg-Dubé syndrome: a large single family cohort.

Background: Birt-Hogg-Dubé (BHD) syndrome is an autosomal dominant condition characterized by dermatologic lesions, pulmonary manifestations, and renal tumors. The syndrome arises from germline mutations in the folliculin (FLCN) gene. We present findings from the single largest family BHD cohort described to date.

Healthcare Use in Individuals with Obesity and Chronic Hypoxemia Treated for Sleep Disordered Breathing.

Study Objectives: To determine if treatment of obstructive sleep apnea (OSA) and obesity hypoventilation syndrome (OHS) among patients with chronic hypoxemia is associated with reduced healthcare utilization.

Methods: We performed a retrospective cohort study of 129 obese, hypoxemic patients who underwent polysomnography and were prescribed positive airway pressure (PAP) therapy. During a 2-year follow-up period we examined the associations between adherence to PAP therapy and rates of hospitalization, emergency room (ER) visits, and outpatient visits.

An observational study of the effectiveness of alternative care providers in the management of obstructive sleep apnea.

Alternative care providers have been proposed as a substitute for physician-based management of obstructive sleep apnea. The purpose of this study was to describe the clinical course of patients with a new diagnosis of obstructive sleep apnea who were treated with continuous positive airway pressure and followed by alternative care providers at a tertiary care sleep clinic. It was hypothesized that care by alternative care providers would result in improvement of daytime sleepiness and satisfactory treatment adherence, and that a specific number of follow-up visits could be identified after which clinical outcomes no longer improved.

Treatment of Sleep Disordered Breathing Liberates Obese Hypoxemic Patients from Oxygen.

Background: Obese hypoxemic patients have a high prevalence of sleep disordered breathing (SDB). It is unclear to what extent treatment of SDB can improve daytime hypoxemia.

Methods: We performed a retrospective cohort study of obese hypoxemic individuals, all of whom underwent polysomnography, arterial blood gas analysis, and subsequent initiation of positive airway pressure (PAP) therapy for SDB.

Flow-volume loop abnormality detecting a previously unrecognized right upper lobe tracheal bronchus.

Tracheal bronchus is a rare anatomic variant in which a bronchus originates from the trachea. Patients may be asymptomatic or present with a variety of respiratory symptoms. We present a case of a patient who presented with a history of poorly controlled asthma and a persistent abnormality of the flow-volume loop.

Use of electronic data and existing screening tools to identify clinically significant obstructive sleep apnea.

Objectives: To assess the ability of electronic health data and existing screening tools to identify clinically significant obstructive sleep apnea (OSA), as defined by symptomatic or severe OSA.

Methods: The present retrospective cohort study of 1041 patients referred for sleep diagnostic testing was undertaken at a tertiary sleep centre in Calgary, Alberta. A diagnosis of clinically significant OSA or an alternative sleep diagnosis was assigned to each patient through blinded independent chart review by two sleep physicians.

Prevalence of Sleep-disordered Breathing in Obese Patients with Chronic Hypoxemia. A Cross-Sectional Study.

Rationale: Hypoxemia in obese patients is likely to be associated with a high prevalence of sleep-disordered breathing. Supplemental oxygen is commonly used to treat chronic hypoxemia but carries some risk in obese individuals due to unrecognized comorbid obstructive sleep apnea (OSA) and obesity hypoventilation syndrome (OHS).

Objectives: The first step in the estimation of this risk is to determine the prevalence of OSA and OHS in obese individuals with chronic, awake hypoxemia.

Effect of treatment of obstructive sleep apnea on depressive symptoms: systematic review and meta-analysis.

Background: Obstructive sleep apnea (OSA) is associated with increased morbidity and mortality, and decreased quality of life. Treatment with continuous positive airway pressure (CPAP) or mandibular advancement devices (MADs) is effective for many symptoms of OSA. However, it remains controversial whether treatment with CPAP or MAD also improves depressive symptoms.

Targeted case finding for OSA within the primary care setting.

Study Objectives: The aim was to determine the feasibility of using an unattended 2-channel device to screen for obstructive sleep apnea in a population of high-risk patients using a targeted, case-finding strategy. The case finding was based on the presence of risk factors not symptoms in the studied population.

Methods: The study took place from June 2007 to May 2008 in rural and metropolitan Queensland and New South Wales.

Identification of insomnia in a sleep center population using electronic health data sources and the insomnia severity index.

Study Objectives: To assess the validity and efficacy of using electronic health data to identify a physician diagnosis of insomnia in a population of patients referred for testing at a tertiary sleep center.

Methods: Retrospective cohort study in a tertiary sleep center in Calgary, Alberta, Canada. Cohort consisted of 1,207 patients referred for sleep diagnostic testing and/or assessment by a sleep physician.

CPAP increases exercise tolerance in obese subjects with obstructive sleep apnea.

Obese subjects commonly suffer from exertional dyspnea and exercise intolerance. Preliminary evidence suggests that treatment with nocturnal continuous positive airway pressure (nCPAP) may improve dyspnea in obese patients with obstructive sleep apnea (OSA), but the effect on exercise tolerance is unknown. This study sought to investigate whether nCPAP improves exercise tolerance and exertional dyspnea in obese patients with OSA.

Nocturnal hypoxia and loss of kidney function.

Background: Although obstructive sleep apnea (OSA) is more common in patients with kidney disease, whether nocturnal hypoxia affects kidney function is unknown.

Methods: We studied all adult subjects referred for diagnostic testing of sleep apnea between July 2005 and December 31 2007 who had serial measurement of their kidney function. Nocturnal hypoxia was defined as oxygen saturation (SaO2) below 90% for ≥12% of the nocturnal monitoring time.

Canadian Thoracic Society 2011 guideline update: diagnosis and treatment of sleep disordered breathing.

The Canadian Thoracic Society (CTS) published an executive summary of guidelines for the diagnosis and treatment of sleep disordered breathing in 2006⁄2007. These guidelines were developed during several meetings by a group of experts with evidence grading based on committee consensus. These guidelines were well received and the majority of the recommendations remain unchanged.