Obstructive sleep apnea severity, circulating biomarkers, and cancer risk.

STUDY OBJECTIVES: To determine if obstructive sleep apnea (OSA) severity and/or biomarkers of inflammation/angiogenesis are associated with incident cancer in this clinical cohort. METHODS: Consenting adult patients at the University of British Columbia Hospital between 2003-2014 completed a questionnaire about their medical history and sleep habits prior to undergoing a polysomnogram (PSG). Blood samples were collected the morning after PSG and processed for biomarkers of inflammation and angiogenesis. The clinical, PSG, and biomarker data were linked to the British Columbia Cancer Registry to ascertain incident cancer diagnoses. Cox proportional hazard regression were used to assess the association between OSA severity and biomarker concentrations with cancer risk. RESULTS: A total of 1,990 patients were included in the analysis with a mean follow-up time of 12.8 years; 181 of them (9.1%) developed cancer after PSG. OSA severity was significantly associated with cancer risk after controlling for relevant covariates (hazard ratio (HR) = 1.08 per 10 events/h apnea-hypopnea index (AHI) increase, CI = 1.02-1.15, p=0.015). In an exploratory analysis, two biomarkers were significantly associated with an increased cancer risk after controlling for relevant covariates (HR per interquartile range (IQR) pg/mL increase of endostatin = 1.45, CI = 1.12-1.87, p=0.01 and HR for IQR pg/mL increase of VCAM-1 = 1.48, CI = 1.04-2.11, p=0.03, respectively). CONCLUSIONS: OSA severity was an independent risk factor for cancer. Furthermore, two circulating markers were significantly associated with cancer risk. If these preliminary findings can be reproduced in other cohorts, biomarkers could potentially be used to prognosticate OSA patients with respect to cancer risk.

Obstructive Sleep Apnea and Mental Health Disorders in the Pediatric Population: A Retrospective Population-based Cohort Study.

RATIONALE: Information is limited about the association between obstructive sleep apnea (OSA) and mental disorders in children. OBJECTIVES: In children, (1) to evaluate the association between OSA and new mental healthcare encounters; (2) to compare mental healthcare encounters two years post- to pre-OSA treatment initiation. METHODS: We conducted a retrospective longitudinal cohort study using Ontario health administrative data (Canada). Children (0-18 years) who underwent diagnostic polysomnography (PSG) 2009-2016 and met criteria for definition of moderate-severe OSA (PSG-OSA) were propensity score weighted by baseline characteristics and compared to children who underwent a PSG in the same period but did not meet the OSA definition (PSG-No-OSA). Children were followed until March 2021. Weighted cause-specific Cox Proportional Hazards and Modified Poisson regression models were used to compare time from PSG to first mental healthcare encounter and frequency of new mental healthcare encounters per person time, respectively. Among those who underwent adenotonsillectomy (AT) or were prescribed and claimed positive airway pressure therapy (PAP), we used age-adjusted conditional logistic regression models to compare two years post- to pre-treatment odds of mental healthcare encounters. RESULTS: Of 32,791 children analyzed, 7,724 (23.6%) children met criteria for moderate-severe OSA. In PSG-OSA group, 7,080 (91.7%) were treated (AT or PAP). Compared to PSG-No-OSA, the PSG-OSA group had a shorter time from PSG to first mental healthcare encounter (HR: 1.08; 95%CI: 1.05-1.12), but less frequent mental healthcare encounters in follow-up (RR: 0.92; 95% CI: 0.87-0.97). OSA treatment (AT or PAP) was associated with lower odds of mental healthcare encounters two years post-treatment initiation compared to two years prior (OR: 0.69; 95% CI: 0.65-0.74). CONCLUSION: In this large population-based study of children who underwent PSG for sleep disorder assessment, OSA diagnosis/treatment was associated with an improvement in some mental health indicators, such as fewer new mental healthcare encounters compared to no OSA, and lower odds of mental healthcare encounters compared to pre-OSA treatment.

The relationship between the morningness-eveningness questionnaire and incident cancer: A historical clinical cohort study.

OBJECTIVE: We conducted a retrospective cohort study to explore the relationship between chronotype measured by the total Morningness-Eveningness Questionnaire (MEQ) score and incident cancer. METHODS: We used clinical and provincial health administrative data on consecutive adults who underwent a Level 1 Polysomnography (PSG) and completed the MEQ between 2010 and 2015 in an academic hospital (Ontario, Canada) and were cancer-free at baseline. Cancer status was derived from the Ontario Cancer Registry. Individuals were followed until death or March 31, 2020. We used multivariable Cox cause-specific regressions to address the research objective. RESULTS: Of 3,004 individuals, 1,781 were analyzed: a median age of 54 years (IQR: 40-64) and 838 (47.1%) men. The median total MEQ score was 63 (IQR: 55-69); 61 (3.4%) were classified as evening (≤41), 536 (30.1%) as intermediate (42-58), and 1,184 (66.5%) as morning chronotypes (≥59). Over a median of 7 years (IQR: 5-8), 120 (6.7%) developed cancer. A U-shape relationship was found between the total MEQ score and an increased hazard of incident cancer, controlling for PSG measures of sleep apnea severity and sleep architecture, demographics, and comorbidities. Compared to the median of 63.0, a total MEQ score greater or less than the median was associated with an increased hazard of incident cancer, with the largest effect for those with a total score ≥76 (e.g., HR of a MEQ total score of 78 vs. 63: 2.01, 95% CI: 1.09-3.71). CONCLUSION: The U-shaped curve may reflect deviations from a standard circadian tendency, which may stress biological systems and influence malignancy risk.

Resource Use and Costs of Indwelling Pleural Catheters versus Pleurodesis for Malignant Pleural Effusions: A Population-based Study.

Rationale: Malignant pleural effusions (MPEs) are associated with significant health service use and healthcare costs, but the current evidence is limited. Objectives: To compare 12-month post-procedure: 1) health service utilization; and 2) healthcare costs after indwelling pleural catheter (IPC) insertion with at-home drainage performed by home care nursing services, versus in-hospital chemical pleurodesis. Methods: We performed a retrospective population-based study on a cohort of adults with MPEs who underwent IPC insertion or chemical pleurodesis between January 1, 2015 and December 31, 2019 using provincial health administrative data (Ontario, Canada). Patients were followed from the procedure date until death or until 12 months after the procedure. Inverse probability of treatment weighting was performed to adjust for imbalances in baseline characteristics. Differences in length of stay, readmissions, emergency department visits, home care visits, and healthcare costs were estimated using weighted regression analysis. Results: Of 5,752 included individuals, 4,432 (77%) underwent IPC insertion and 1,320 (23%) had pleurodesis. In the weighted sample, individuals who received an IPC had fewer inpatient days (12.4 d vs. 16 d; standardized mean difference, 0.229) but a higher proportion of subsequent admissions for empyema (2.7% vs. 1.1%; P = 0.0002) than those undergoing pleurodesis. Individuals with IPCs received more hours of nursing home care (41 h vs. 21.1 h; standardized mean difference, 0.671) but overall had lower average healthcare costs ($40,179 vs. $46,640 per patient; standardized mean difference, 0.177) than those receiving pleurodesis. Conclusions: IPCs with home nursing drainage are associated with reduced health resource use compared with pleurodesis in adults with MPEs, even after controlling for important baseline and clinical characteristics. Given that both procedures have similar health outcomes, our findings support the ongoing promotion of IPCs to increase outpatient management of patients with MPEs.

Obstructive sleep apnea in those with idiopathic intracranial hypertension undergoing diagnostic in-laboratory polysomnography.

RATIONALE: The association of obstructive sleep apnea (OSA) with idiopathic intracranial hypertension (IIH) remains unclear, and few studies have used objective in-laboratory polysomnography (PSG) data. Thus, we used PSG data to examine the: 1) association between OSA, and its severity, with IIH and 2) sex differences in OSA severity in those with and without IIH. METHODS: We retrospectively analyzed diagnostic PSG data from January 2015 to August 2023 for patients who were diagnosed with IIH by a neuro-ophthalmologist using the modified Dandy criteria. We selected three age, sex, and body mass index (BMI) matched controls for each IIH patient. We examined potential associations of IIH with OSA using regression. Sex differences were analyzed using ANOVA. RESULTS: Of 3482 patients who underwent PSG, we analyzed 78 IIH patients (16 males) and 234 matched controls (48 males). Five (6.4 %) IIH and 39 (16.7 %) control patients had OSA, defined as AHI≥15. After adjusting for age, sex, BMI, and comorbidities, IIH was negatively associated with the presence of OSA (OR 0.29, 95%CI 0.10-0.87, p = 0.03). However, models that adjusted for acetazolamide use, with or without comorbidities, showed no significant relationship with OSA (OR 0.31, p = 0.20). Males with IIH had a significantly higher age (p = 0.020), OSA severity (p = 0.032), and arousal index (p = 0.046) compared to females with IIH. CONCLUSIONS: IIH treated with acetazolamide was not an independent risk factor for OSA presence or severity. The presence of IIH treated with acetazolamide likely does not warrant routine screening for OSA, but related risk factors may identify appropriate patients.

Polysomnographic Assessment of Sleep Disturbances in Cancer Development: A Historical Multicenter Clinical Cohort Study.

BACKGROUND: Many cellular processes are controlled by sleep. Therefore, alterations in sleep might be expected to stress biological systems that could influence malignancy risk. RESEARCH QUESTION: What is the association between polysomnographic measures of sleep disturbances and incident cancer, and what is the validity of cluster analysis in identifying polysomnography phenotypes? STUDY DESIGN AND METHODS: We conducted a retrospective multicenter cohort study using linked clinical and provincial health administrative data on consecutive adults free of cancer at baseline with polysomnography data collected between 1994 and 2017 in four academic hospitals in Ontario, Canada. Cancer status was derived from registry records. Polysomnography phenotypes were identified by k-means cluster analysis. A combination of validation statistics and distinguishing polysomnographic features was used to select clusters. Cox cause-specific regressions were used to assess the relationship between identified clusters and incident cancer. RESULTS: Among 29,907 individuals, 2,514 (8.4%) received a diagnosis of cancer over a median of 8.0 years (interquartile range, 4.2-13.5 years). Five clusters were identified: mild (mildly abnormal polysomnography findings), poor sleep, severe OSA or sleep fragmentation, severe desaturations, and periodic limb movements of sleep (PLMS). The associations between cancer and all clusters compared with the mild cluster were significant while controlling for clinic and year of polysomnography. When additionally controlling for age and sex, the effect remained significant only for PLMS (adjusted hazard ratio [aHR], 1.26; 95% CI, 1.06-1.50) and severe desaturations (aHR, 1.32; 95% CI, 1.04-1.66). Further controlling for confounders, the effect remained significant for PLMS, but was attenuated for severe desaturations. INTERPRETATION: In a large cohort, we confirmed the importance of polysomnographic phenotypes and highlighted the role that PLMS and oxygenation desaturation may play in cancer. Using this study's findings, we also developed an Excel (Microsoft) spreadsheet (polysomnography cluster classifier) that can be used to validate the identified clusters on new data or to identify which cluster a patient belongs to. TRIAL REGISTRY: ClinicalTrials.gov; Nos.: NCT03383354 and NCT03834792; URL: www. CLINICALTRIALS: gov.

Association between frailty and patient outcomes after cancer surgery: a population-based cohort study.

BACKGROUND: Frailty is associated with poor postoperative outcomes, but existing data do not describe frailty's interaction with tumour characteristics at the time of cancer surgery. Our objective was to estimate the association between frailty and long-term survival, and to explore any interaction with tumour stage and grade. METHODS: This was a population-based cohort study conducted using linked provincial health administrative data in Ontario, Canada (2009-20). Using a cancer registry, we identified adults having elective cancer surgery. Frailty was measured using a validated index (range 0-1; higher score=greater frailty). Associations between frailty and long-term postoperative survival (primary outcome) were estimated using proportional hazards regression. Secondary outcomes were length of stay, discharge destination, days alive at home, and healthcare costs. RESULTS: We identified and included 52 012 patients. Mean frailty score was 0.13 (standard deviation 0.07). During follow-up, 19 378 (37.3%) patients died. After adjustment for risk factors, each 10% increase in frailty was associated with a 1.60-fold relative decrease in survival (95% confidence interval: 1.56-1.64). The frailty-survival association was strongest for patients with lower stage and grade cancers. Increased frailty was associated with longer hospital stays (3 days), fewer days alive and at home (42 days yr-1), more frequent discharge to a nursing facility (2.38-fold), and increased healthcare costs ($6048). CONCLUSIONS: Patient frailty is associated with decreased long-term survival after cancer surgery. The association is stronger for early-stage and -grade cancers, which would otherwise have a better survival prognosis.

Association of Palliative Care with Days at Home and Healthcare Use in Patients with Advanced Chronic Obstructive Pulmonary Disease: A Cohort Study.

Rationale: Palliative care focuses on improving quality of life for patients with life-limiting conditions. Although previous studies have shown palliative care to be associated with reduced acute healthcare use in people with cancer and other illnesses, these findings may not generalize to patients with chronic obstructive pulmonary disease (COPD). Objectives: We examined the association between palliative care and rates of days at home, locations of death, and acute healthcare use in patients with COPD. Methods: We used health administrative databases in Ontario, Canada, to identify patients with advanced COPD hospitalized between April 2010 and March 2017 and followed up until March 2018. Patients who received palliative care were matched 1:1 with those who did not receive palliative care in terms of age, sex, long-term oxygen, previous COPD hospitalizations and propensity scores. Rate ratios (RR) were estimated by using Poisson models with generalized estimating equations to account for matching. Results: Among 35,492 patients, 1,788 (5%) received palliative care. In the matched cohort (1,721 pairs), people with COPD receiving palliative care had similar rates of days at home (RR, 1.01; 95% confidence interval [CI], 0.97-1.05) but were more likely to die at home (16.4% vs. 10.0%; P < 0.001) compared with those who did not receive palliative care. Rates of healthcare use were similar except for increased hospitalizations in the palliative care group (RR, 1.09; 95% CI, 1.01-1.18). Conclusions: Receipt of palliative care did not reduce days at home or healthcare use but was associated with a modest increase in the proportion who died at home. Future work should evaluate palliative care strategies designed specifically for patients with COPD.

Polysomnographic Markers of Obstructive Sleep Apnea Severity and Cancer-related Mortality: A Large Retrospective Multicenter Clinical Cohort Study.

Rationale: The evidence for an association between cancer survival and obstructive sleep apnea (OSA) remains underexplored. Objectives: To evaluate an association between markers of OSA severity (respiratory disturbances, hypoxemia, and sleep fragmentation) and cancer-related mortality in individuals with previously diagnosed cancer. Methods: We conducted a multicenter retrospective cohort study using linked clinical and provincial health administrative data on consecutive adults who underwent a diagnostic sleep study between 1994 and 2017 in four Canadian academic hospitals and were previously diagnosed with cancer through the Ontario Cancer Registry. Multivariable cause-specific Cox regressions were used to address the research objective. Results: We included 2,222 subjects. Over a median follow-up time of 5.6 years (interquartile range [IQR], 2.7-9.1 years), 261/2,222 (11.7%) individuals with prevalent cancer died from cancer-related causes, which accounted for 44.2% (261/590) of all-cause death. Controlling for age, sex, alcohol use disorder, prior heart failure, chronic obstructive pulmonary disease, hypertension, diabetes, treatment for OSA, clinic site, year of the sleep study, and time since the cancer diagnosis, measures of hypoxemia and sleep fragmentation, but not apnea-hypopnea index, were significantly associated with the cancer-specific mortality: percentage of time spent with arterial oxygen saturation (SaO2) < 90% (hazard ratio [HR] per 5% increase, 1.05; 95% confidence interval, 1.01-1.09); mean SaO2 (HR per 3% increase, 0.79; 0.68-0.92); and percentage of stage 1 sleep (HR per 16% increase, 1.27; 1.07-1.51). Conclusions: In a large clinical cohort of adults with suspected OSA and previously diagnosed cancer, measures of nocturnal hypoxemia and sleep fragmentation as markers of OSA severity were significantly associated with cancer-related mortality, suggesting the need for more targeted risk awareness.

Morbidity and mortality reduction associated with polysomnography testing in idiopathic pulmonary fibrosis: a population-based cohort study.

BACKGROUND: It is not well-known if diagnosing and treating sleep breathing disorders among individuals with idiopathic pulmonary fibrosis (IPF) improves health outcomes. We evaluated the association between receipt of laboratory-based polysomnography (which is the first step in the diagnosis and treatment of sleep breathing disorders in Ontario, Canada) and respiratory-related hospitalization and all-cause mortality among individuals with IPF. METHODS: We used a retrospective, population-based, cohort study design, analyzing health administrative data from Ontario, Canada, from 2007 to 2019. Individuals with IPF were identified using an algorithm based on health administrative codes previously developed by IPF experts. Propensity score matching was used to account for potential differences in 41 relevant covariates between individuals that underwent polysomnography (exposed) and individuals that did not undergo polysomnography (controls), in order minimize potential confounding. Respiratory-related hospitalization and all-cause mortality were evaluated up to 12 months after the index date. RESULTS: Out of 5044 individuals with IPF identified, 201 (4.0%) received polysomnography, and 189 (94.0%) were matched to an equal number of controls. Compared to controls, exposed individuals had significantly reduced rates of respiratory-related hospitalization (hazard ratio [HR] 0.43, 95% confidence interval [CI] 0.24-0.75), p = 0.003) and all-cause mortality (HR 0.49, 95% CI 0.30-0.80), p = 0.004). Significantly reduced rate of respiratory-related hospitalization (but not all-cause mortality) was also observed among those with > = 1 respiratory-related hospitalization (HR 0.38, 95% CI 0.15-0.99) and systemic corticosteroid receipt (HR 0.37, 95% CI 0.19-0.94) in the year prior to the index date, which reflect sicker subgroups of persons. CONCLUSIONS: Undergoing polysomnography was associated with significantly improved clinically-important health outcomes among individuals with IPF, highlighting the potential importance of incorporating this testing in IPF disease management.

Prevalence and burden of obstructive lung disease in the urban poor population of Ottawa, Canada: a community-based mixed-method, observational study.

BACKGROUND: Globally the burden of Obstructive Lung Diseases (OLD) is growing, however its effect on urban poor populations with the high prevalence of tobacco dependence is virtually unknown. The purpose of this project is to estimate the prevalence and burden of OLD in the urban, low-income populations of Ottawa, Canada. METHODS: The study presented in this paper was part of the PROMPT (Management and Point-of-Care for Tobacco Dependence) project; a prospective cohort study in a community-based setting (n = 80) with meaningful Patient Engagement from design to dissemination. Spirometry data, standardized questionnaires and semi-structured interviews from PROMPT were interpreted to understand the lung function, disease burden and social determinants (respectively) in this population. RESULTS: The prevalence of OLD among those who completed spirometry (N = 64) was 45-59%. Generic and disease-specific quality of life was generally poor in all PROMPT participants, even those without OLD, highlighting the higher disease burden this vulnerable population faces. Quality of life was impacted by two major themes, including i) socioeconomic status and stress and ii) social networks and related experiences of trauma. CONCLUSION: The prevalence and disease burden of OLD is significantly higher in Ottawa's urban poor population than what is observed in the general Canadian population who smoke, suggesting an etiological role of the social determinants of health. This urges the need for comprehensive care programs addressing up-stream factors leading to OLDs, including poor access and utilization of preventive healthcare addressing the social determinants of health. TRIAL REGISTRATION: ClinicalTrails.gov - NCT03626064 , Retrospective registered: August 2018.

Obstructive Sleep Apnea and Incident Cancer: A Large Retrospective Multicenter Clinical Cohort Study.

BACKGROUND: To examine the association between the severity of obstructive sleep apnea (OSA) and nocturnal hypoxemia with incident cancer. METHODS: This was a multicenter retrospective clinical cohort study using linked clinical and provincial health administrative data on consecutive adults who underwent a diagnostic sleep study between 1994 and 2017 in four academic hospitals (Canada) who were free of cancer at baseline. Cancer status was derived from the Ontario Cancer Registry. Cox cause-specific regressions were utilized to address the objective and to calculate the 10-year absolute risk difference (ARD) in the marginal probability of incident cancer and the number needed to harm (NNH). RESULTS: Of 33,997 individuals considered, 33,711 with no missing OSA severity were included: median age, 50 years; 58% male; and 23% with severe OSA (apnea-hypopnea index >30). Of the 18,458 individuals with information on sleep time spent with oxygen saturation (SaO2) <90%, 5% spent >30% of sleep with SaO2 <90% (severe nocturnal hypoxemia). Over a median of 7 years, 2,498 of 33,711 (7%) individuals developed cancer, with an incidence rate of 10.3 (10.0-10.8) per 1,000 person-years. Controlling for confounders, severe OSA was associated with a 15% increased hazard of developing cancer compared with no OSA (HR = 1.15, 1.02-1.30; ARD = 1.28%, 0.20-2.37; and NNH = 78). Severe hypoxemia was associated with about 30% increased hazard (HR = 1.32, 1.08-1.61; ARD = 2.38%, 0.47-4.31; and NNH = 42). CONCLUSIONS: In a large cohort of individuals with suspected OSA free of cancer at baseline, the severity of OSA and nocturnal hypoxemia was independently associated with incident cancer. IMPACT: These findings suggest the need for more targeted cancer risk awareness in individuals with OSA.

Air Pollution and Systemic Inflammation in Patients With Suspected OSA Living in an Urban Residential Area.

BACKGROUND: Air pollution and OSA are independently associated with systemic inflammation, but it is unknown if these exposures interact to influence systemic inflammation. RESEARCH QUESTION: The study objective was to determine the relative importance of these factors and their combined potential to influence systemic inflammation in patients under assessment for sleep ailments. STUDY DESIGN AND METHODS: A total of 315 patients contributed data, including a questionnaire, polysomnogram, and morning serum IL-6 and IL-10 concentrations. For each patient, residential annual average air pollution exposure (nitrogen dioxide [NO2], black carbon [BC], and particulate matter with an aerodynamic diameter ≤ 2.5 µm [PM2.5]) was estimated with a land use regression model. Linear regression modeling was used adjusting for age, sex, apnea-hypopnea index, BMI, smoking, socioeconomic status, and comorbidities. RESULTS: In adjusted models, quartile 4 PM2.5 exposure (compared with quartiles 1-3) was associated with increased IL-6 and IL-10 concentrations (estimated adjusted, 7.1 pg/mL [95% CI, 2.5-11.7; P < .01] and 71.4 pg/mL [95% CI, 38.2-103.7; P < .0001], respectively). OSA, BC, and NO2 were not associated with IL-6 or IL-10 in similar analyses; however, moderate to severe OSA influenced the effect of BC on IL-6 (interaction term, P = .01), with no significant interaction terms observed for NO2 or PM2.5. Subsequent stratified analysis showed that in the 173 patients with moderate to severe OSA, quartile 4 BC exposure (compared with quartiles 1-3) was associated with an increased IL-6 concentration (estimated adjusted, 8.9 pg/mL; 95% CI, 1.7-16.1; P = .02). INTERPRETATION: Long-term residential PM2.5 exposure was associated with increased IL-6 and IL-10 concentrations in patients evaluated for suspected OSA. BC exposure was also associated with increased IL-6 but only in the subgroup of patients with moderate to severe OSA. These data suggest the potential for joint effects of moderate to severe OSA and air pollution on systemic inflammation.

End-of-life care in individuals with respiratory diseases: a population study comparing the dying experience between those with chronic obstructive pulmonary disease and lung cancer.

Purpose: Among individuals with COPD and/or lung cancer, to describe end-of-life health service utilization, costs, and place of death; to identify predictors of home palliative care use, and to assess benefits associated with palliative care use. Patients and methods: We conducted a retrospective population-based study using provincial linked health administrative data (Ontario, Canada) between 2010 and 2015. We examined health care use in the last 90 days of life in adults 35 years and older with physician-diagnosed COPD and/or lung cancer identified using a validated algorithm and the Ontario Cancer Registry, respectively. Four mutually exclusive groups were considered: (i) COPD only, (ii) lung cancer only, (iii) COPD and lung cancer, and (iv) neither COPD nor lung cancer. Multivariable generalized linear models were employed. Results: Of 445,488 eligible deaths, 34% had COPD only, 4% had lung cancer only, 5% had both and 57% had neither. Individuals with COPD only received less palliative care (20% vs 57%) than those with lung cancer only. After adjustment, people with lung cancer only were far more likely to receive palliative care (OR=4.22, 4.08-4.37) compared to those with neither diagnosis, while individuals with COPD only were less likely to receive palliative care (OR=0.82, 0.81-0.84). Home palliative care use was associated with reduced death and fewer days in acute care, and less cost, regardless of the diagnosis. Conclusion: Although individuals with lung cancer were much more likely to receive palliative care than those with COPD, both populations were underserviced. Results suggest greater involvement of palliative care may improve the dying experience of these populations and reduce costs.

Sleep Apnea Increases the Risk of New Hospitalized Atrial Fibrillation: A Historical Cohort Study.

OBJECTIVES: This study examined the relationship between newly diagnosed OSA and incident hospitalized atrial fibrillation (AF) over the subsequent 10 years in a large arrhythmia-free cohort. METHODS: Adults referred between 1994 and 2010 to a large academic hospital with suspected OSA who were arrhythmia-free at the time of the first diagnostic sleep study were included. Clinical data were linked to provincial health administrative data to define outcome. Cox regressions were used to investigate the relationship between severity of OSA as measured by the apnea-hypopnea index (AHI) and degree of nocturnal hypoxemia, and incident hospitalized AF. RESULTS: In total, 8,256 subjects were included in this study. Their median age was 47 years, 62% were men; 28% had an AHI > 30 events per hour, and 6% spent > 30% of sleep time with oxygen saturation < 90%. Over a median follow-up of 10 years (interquartile range, 7-13 years), 173 participants (2.1%) were hospitalized with AF. Controlling for age, sex, alcohol consumption, smoking status, previous heart failure, COPD, and pulmonary embolism, nocturnal hypoxemia (but not AHI) was a significant predictor of incident AF: hazard ratio, 2.47 (95% CI, 1.64-3.71). After further controlling for BMI and hypertension, this association was attenuated but remained significant (hazard ratio, 1.77 [95% CI, 1.15-2.74]). CONCLUSIONS: In a large arrhythmia-free clinical cohort with suspected OSA, nocturnal hypoxemia was independently associated with a 77% increased hazard of incident hospitalized AF. These findings further support a relationship between OSA, nocturnal hypoxemia, and new-onset AF, and they may be used to enhance AF prevention in patients with OSA and severe nocturnal hypoxemia.

Profile of CPAP treated patients in Ontario, Canada, 2006-2013: a population-based cohort study.

RATIONALE: Many studies have demonstrated the benefits of treating obstructive sleep apnea (OSA) with continuous positive airway pressure (CPAP). However, both recognition of OSA and acceptance of treatment are suboptimal. Current data on CPAP initiation at a population level is lacking. OBJECTIVES: The objectives were to determine the rate of CPAP initiations in Ontario, Canada (population ∼13,000,000), and to profile these individuals over time. METHODS: We conducted a population based cohort study between 2006 and 2013. All adults who initiated CPAP for OSA were included. Patient characteristics, comorbidities and health care utilization at the time of CPAP initiation were derived from provincial health administrative data. Changes in patient characteristics over time were assessed. RESULTS: Over eight years, 216,514 individuals initiated CPAP therapy in comparison to 802,188 individuals who underwent diagnostic polysomnography (PSG) during that time. The rate of new CPAP initiations increased from 18.6/10,000 in 2006 to 28.7/10,000 in 2008 and then plateaued with an annual increase of less than 1/10,000 from 2008 to 2013. More women and middle aged (50+) individuals initiated CPAP as did more low income Ontarians. Comorbidities were common and the frequency of congestive heart failure, chronic kidney disease, and cancer increased during the study period. CONCLUSIONS: Over an eight year period CPAP initiation appears to have plateaued in spite of increasing PSG testing; however, those receiving treatment with CPAP are increasingly complex and a greater proportion are women.

End-of-Life Strategies among Patients with Advanced Chronic Obstructive Pulmonary Disease.

RATIONALE: The burden of advanced chronic obstructive pulmonary disease (COPD) is high globally; however, little is known about how often end-of-life strategies are used by this population. OBJECTIVES: To describe trends in the use of end-of-life care strategies by people with advanced COPD in Ontario, Canada. METHODS: A population-based repeated cross-sectional study examining end-of-life care strategies in individuals with advanced COPD was conducted. Annual proportions of individuals who received formal palliative care, long-term oxygen therapy, or opioids from 2004 to 2014 were determined. Results were age and sex standardized and stratified by age, sex, socioeconomic status, urban/rural residence, and immigrant status. Measurement/Main Results: There were 151,912 persons with advanced COPD in Ontario between 2004 and 2014. Use of formal palliative care services increased 1% per year from 5.3% in 2004 to 14.3% in 2014 (P value for trend < 0.001), whereas use of long-term oxygen therapy increased 1.1% per year from 26.4% in 2004 to 35.3% in 2013 (P value for trend < 0.001). The use of opioids was relatively stable (40.0% in 2004 and 41.8% in 2014; P value for trend = 0.08). Younger individuals were less likely to use formal palliative care services and long-term oxygen therapy. Males were less likely than females to receive long-term oxygen therapy and opioids. CONCLUSIONS: The proportion of people with advanced COPD using end-of-life strategies, although increasing, remains low. Efforts should focus on increasing access to such strategies and educating patients and providers of their benefits.