Global asthma prevalence in adults: findings from the cross-sectional world health survey

Background

Asthma is a major cause of disability, health resource utilization and poor quality of life world-wide. We set out to generate estimates of the global burden of asthma in adults, which may inform the development of strategies to address this common disease.

Methods

The World Health Survey (WHS) was developed and implemented by the World Health Organization in 2002-2003. A total of 178,215 individuals from 70 countries aged 18 to 45 years responded to questions related to asthma and related symptoms. The prevalence of asthma was based on responses to questions relating to self-reported doctor diagnosed asthma, clinical/treated asthma, and wheezing in the last 12 months.

Results

The global prevalence rates of doctor diagnosed asthma, clinical/treated asthma and wheezing in adults were 4.3%, 4.5%, and 8.6% respectively, and varied by as much as 21-fold amongst the 70 countries. Australia reported the highest rate of doctor diagnosed, clinical/treated asthma, and wheezing (21.0%, 21.5%, and 27.4%). Amongst those with clinical/treated asthma, almost 24% were current smokers, half reported wheezing, and 20% had never been treated for asthma.

Conclusions

This study provides a global estimate of the burden of asthma in adults, and suggests that asthma continues to be a major public health concern worldwide. The high prevalence of smoking remains a major barrier to combating the global burden of asthma. While the highest prevalence rates were observed in resource-rich countries, resource-poor nations were also significantly affected, posing a barrier to development as it stretches further the demands of non-communicable diseases.

Identifying patients with physician-diagnosed asthma in health administrative databases

BACKGROUND

Asthma imposes a heavy and expensive burden on individuals and populations. A population-based surveillance and research program based on health administrative data could measure and study the burden of asthma; however, the validity of a health administrative data diagnosis of asthma must first be confirmed.

OBJECTIVE

To evaluate the accuracy of population-based provincial health administrative data in identifying adult patients with asthma for ongoing surveillance and research.

METHODS

Patients from randomly selected primary care practices were assigned to four categories according to their previous diagnoses: asthma, chronic obstructive pulmonary disease, related respiratory conditions and nonasthma conditions. In each practice, 10 charts from each category were randomly selected, abstracted, then reviewed by a blinded expert panel who identified them as asthma or nonasthma. These reference standard diagnoses were then linked to the patients' provincial records and compared with health administrative algorithms designed to identify asthma. Analyses were performed using the concepts of diagnostic test evaluation.

RESULTS

A total of 518 charts, including 160 from individuals with asthma, were reviewed. The algorithm of two or more ambulatory care visits and/or one or more hospitalization(s) for asthma in two years had a sensitivity of 83.8% (95% CI 77.1% to 89.1%) and a specificity of 76.5% (95% CI 71.8% to 80.8%).

CONCLUSION

Definitions of adult asthma using health administrative data are sensitive and specific for identifying adults with asthma. Using these definitions, cohorts of adults with asthma for ongoing population-based surveillance and research can be developed.

Varicella-zoster virus-specific immune responses in elderly recipients of a herpes zoster vaccine

BACKGROUND

A double-blind, placebo-controlled trial that involved 38,546 subjects > or =60 years old demonstrated efficacy of a high-potency live-attenuated Oka/Merck varicella-zoster virus (VZV) vaccine. The trial included an immunology substudy to determine the relationship of VZV-specific immune responses to vaccination and clinical outcome.

METHODS

The immunology substudy enrolled 1395 subjects at 2 sites where blood samples obtained prior to vaccination, at 6 weeks after vaccination, and at 1, 2, and 3 years thereafter were tested for VZV-specific cell-mediated immunity (VZV-CMI) by gamma-interferon ELISPOT and responder cell frequency assays and for VZV antibody by glycoprotein ELISA.

RESULTS

VZV-CMI and VZV antibodies were significantly increased in vaccine recipients at 6 weeks after vaccination. The vaccine-induced increases in VZV-CMI persisted during the 3 years of follow-up, although their magnitude decreased over time. The magnitude of these VZV-specific immune responses was greater in subjects 60-69 years old than in subjects > or =70 years old.

CONCLUSIONS

The zoster vaccine induced a significant increase in VZV-CMI and VZV antibody. The magnitude and duration of the boost in VZV-CMI in vaccine recipients and the relationship of this boost to age paralleled the clinical effects of the vaccine observed during the efficacy trial. These findings support the hypothesis that boosting VZV-CMI protects older adults against herpes zoster and postherpetic neuralgia.

Pharmacologic Management of Chronic Obstructive Pulmonary Disease. An Official American Thoracic Society Clinical Practice Guideline

Background: This document provides clinical recommendations for the pharmacologic treatment of chronic obstructive pulmonary disease (COPD). It represents a collaborative effort on the part of a panel of expert COPD clinicians and researchers along with a team of methodologists under the guidance of the American Thoracic Society.

Methods: Comprehensive evidence syntheses were performed on all relevant studies that addressed the clinical questions and critical patient-centered outcomes agreed upon by the panel of experts. The evidence was appraised, rated, and graded, and recommendations were formulated using the Grading of Recommendations, Assessment, Development, and Evaluation approach.

Results: After weighing the quality of evidence and balancing the desirable and undesirable effects, the guideline panel made the following recommendations: 1) a strong recommendation for the use of long-acting β₂-agonist (LABA)/long-acting muscarinic antagonist (LAMA) combination therapy over LABA or LAMA monotherapy in patients with COPD and dyspnea or exercise intolerance; 2) a conditional recommendation for the use of triple therapy with inhaled corticosteroids (ICS)/LABA/LAMA over dual therapy with LABA/LAMA in patients with COPD and dyspnea or exercise intolerance who have experienced one or more exacerbations in the past year; 3) a conditional recommendation for ICS withdrawal for patients with COPD receiving triple therapy (ICS/LABA/LAMA) if the patient has had no exacerbations in the past year; 4) no recommendation for or against ICS as an additive therapy to long-acting bronchodilators in patients with COPD and blood eosinophilia, except for those patients with a history of one or more exacerbations in the past year requiring antibiotics or oral steroids or hospitalization, for whom ICS is conditionally recommended as an additive therapy; 5) a conditional recommendation against the use of maintenance oral corticosteroids in patients with COPD and a history of severe and frequent exacerbations; and 6) a conditional recommendation for opioid-based therapy in patients with COPD who experience advanced refractory dyspnea despite otherwise optimal therapy.

Conclusions: The task force made recommendations regarding the pharmacologic treatment of COPD based on currently available evidence. Additional research in populations that are underrepresented in clinical trials is needed, including studies in patients with COPD 80 years of age and older, those with multiple chronic health conditions, and those with a codiagnosis of COPD and asthma.

Lifetime risk of developing chronic obstructive pulmonary disease: a longitudinal population study

BACKGROUND

Although chronic obstructive pulmonary disease (COPD) is one of the most deadly, prevalent, and costly chronic diseases, no comprehensive estimates of the risk of developing COPD in the general population have been published. We aimed to quantify the lifetime risk of developing physician-diagnosed COPD in a large, multicultural North American population.

METHODS

We did a retrospective longitudinal cohort study using population-based health administrative data from Ontario, Canada (total population roughly 13 million). All individuals free of COPD in 1996 were monitored for up to 14 years for three possible outcomes; diagnosis of COPD by a physician, reached 80 years of age, or death. COPD was identified with a previously validated case definition based on COPD health services claims. The cumulative incidence of physician-diagnosed COPD over a lifetime adjusted for the competing risk of death was calculated by a modified survival analysis technique. Results were stratified by sex, socioeconomic status, and whether individuals lived in a rural or urban setting.

FINDINGS

A total of 579,466 individuals were diagnosed with COPD by a physician over the study period. The overall lifetime risk of physician-diagnosed COPD at age 80 years was 27·6%. Lifetime risk was higher in men than in women (29·7%vs 25·6%), individuals of lower socioeconomic status than in those of higher socioeconomic status (32·1%vs 23·0%), and individuals who lived in a rural setting than in those who lived in an urban setting (32·4%vs 26·7%).

INTERPRETATION

About one in four individuals are likely to be diagnosed and receive medical attention for COPD during their lifetime. Clinical evidence-based approaches, public health action, and more research are needed to identify effective strategies to prevent COPD and ensure that those with the disease have the highest quality of life possible.

FUNDING

Government of Ontario, Canada.

Obstructive sleep apnea and incident diabetes. A historical cohort study

RATIONALE

Despite emerging evidence that obstructive sleep apnea (OSA) may cause metabolic disturbances independently of other known risk factors, it remains unclear whether OSA is associated with incident diabetes.

OBJECTIVES

To evaluate whether risk of incident diabetes was related to the severity and physiologic consequences of OSA.

METHODS

A historical cohort study was conducted using clinical and provincial health administrative data. All adults without previous diabetes referred with suspected OSA who underwent a diagnostic sleep study at St. Michael's Hospital (Toronto, Canada) between 1994 and 2010 were followed through health administrative data until May 2011 to examine the occurrence of diabetes. All OSA-related variables collected from the sleep study were examined as predictors in Cox regression models, controlling for sex, age, body mass index, smoking status, comorbidities, and income.

MEASUREMENTS AND MAIN RESULTS

Over a median follow-up of 67 months, 1,017 (11.7%) of 8,678 patients developed diabetes, giving a cumulative incidence at 5 years of 9.1% (95% confidence interval, 8.4-9.8%). In fully adjusted models, patients with apnea-hypopnea index (AHI) greater than 30 had a 30% higher hazard of developing diabetes than those with AHI less than 5. Among other OSA-related variables, AHI in rapid eye movement sleep and time spent with oxygen saturation less than 90% were associated with incident diabetes, as were heart rate, neck circumference, and sleep time.

CONCLUSIONS

Among people with OSA, and controlling for multiple confounders, initial OSA severity and its physiologic consequences predicted subsequent risk for incident diabetes.

Untreated obstructive sleep apnea and the risk for serious long-term adverse outcomes: a systematic review

BACKGROUND

Reports on the association between obstructive sleep apnea (OSA) and risk of death, cardiovascular (CV) events, diabetes and depression have been inconsistent.

METHODS

We conducted a systematic review of the prognostic value of clinical and polysomnographic (PSG) characteristics of OSA for adverse long-term outcomes of untreated OSA in adult patients. A comprehensive search strategy for prognosis studies, OSA, CV events, mortality, depression and diabetes was developed in collaboration with a medical information specialist. All English language studies, from Jan 1999 to Dec 2011, with longitudinal design in adults with OSA diagnosed by PSG recording, found through Medline, Embase and bibliographies of identified articles, were considered eligible. Quality was assessed using published guidelines.

RESULTS

Among 26 articles, ten evaluated the association of OSA with mortality, 9 with a composite CV outcome, 4 with stroke, 2 with diabetes and 1 with depression. Significant relationships between the apnea-hypopnea index (AHI) and outcomes of interest were reported in 18 studies: seven for all-cause mortality, six for composite CV events, three for stroke, one for diabetes and one for depression. The effect of AHI was attenuated by female gender, older age, absence of daytime sleepiness and higher body mass index. Due to clinical heterogeneity between studies, meta-analyses were not performed.

CONCLUSION

Evidence exists in men for a relationship between OSA and all-cause mortality and a composite CV outcome. Associations between OSA and other outcomes remain uncertain. Among OSA-specific markers, only AHI was a consistent predictor. Other consistent predictors were traditional CV risk factors. Research is required to identify effect modifiers and the predictive ability of various AHI threshold values and hypopnea definitions. An enhanced set of OSA-specific predictors will allow better risk stratification to guide OSA treatment.

Restriction fragment length polymorphism of polymerase chain reaction products from vaccine and wild-type varicella-zoster virus isolates

The nucleotide changes that result in two restriction endonuclease polymorphisms that differentiate wild-type varicella-zoster virus (VZV) from the vaccine strain were determined. Oligonucleotide primers that flank these sites were used to amplify the intervening sequences with the polymerase chain reaction to identify VZV DNA in clinical isolates. Restriction enzyme digestion of the amplification products distinguished vaccine and wild-type genomes from one another. This study confirms the feasibility of amplifying VZV sequences so that they may be detected in clinical specimens and provides a molecular epidemiological approach to strain identification of VZV in vesicular lesions.

Israeli preschool children under Scuds: a 30-month follow-up

OBJECTIVE

Longitudinal studies of children exposed to traumatic events show contrasting findings regarding their symptomatic change over time. The present study reports on a 30-month follow-up of preschool children and their mothers who had been exposed to Scud missile attacks.

METHOD

Families displaced during the Gulf War after their homes had been damaged by the missile attack and a control group whose homes remained intact were interviewed about posttraumatic and general symptomatology, the mothers' capacity to control images, and the children's adaptive behavior.

RESULTS

Stress symptoms decreased in the displaced children but not in their mothers. Both reported more posttraumatic symptoms than did the control group. No differences in the children's adaptive behavior were observed. Posttraumatic symptoms of the displaced children correlated with the mothers' avoidant symptoms. The mothers' avoidant symptoms at follow-up were statistically explained by the mothers' symptoms during the war and their capacity for image control, the duration of displacement, and the cohesion of the family.

CONCLUSIONS

The maternal stress-buffering capacity constitutes a central element in children's protective matrix and is crucial in minimizing long-term internal suffering of traumatized preschool children.

The Cardiovascular Health in Ambulatory Care Research Team (CANHEART): using big data to measure and improve cardiovascular health and healthcare services

BACKGROUND

The CArdiovascular HEalth in Ambulatory care Research Team (CANHEART) is conducting a unique, population-based observational research initiative aimed at measuring and improving cardiovascular health and the quality of ambulatory cardiovascular care provided in Ontario, Canada. A particular focus will be on identifying opportunities to improve the primary and secondary prevention of cardiovascular events in Ontario's diverse multiethnic population.

METHODS AND RESULTS

A population-based cohort comprising 9.8 million Ontario adults ≥20 years in 2008 was assembled by linking multiple electronic survey, health administrative, clinical, laboratory, drug, and electronic medical record databases using encoded personal identifiers. The cohort includes ≈9.4 million primary prevention patients and ≈400,000 secondary prevention patients. Follow-up on clinical events is achieved through record linkage to comprehensive hospitalization, emergency department, and vital statistics administrative databases. Profiles of cardiovascular health and preventive care will be developed at the health region level, and the cohort will be used to study the causes of regional variation in the incidence of major cardiovascular events and other important research questions.

CONCLUSIONS

Linkage of multiple databases will enable the CANHEART study cohort to serve as a powerful big data resource for scientific research aimed at improving cardiovascular health and health services delivery. Study findings will be shared with clinicians, policy makers, and the public to facilitate population health interventions and quality improvement initiatives.

Chronic obstructive pulmonary disease and socioeconomic status: a systematic review

BACKGROUND

Along with age and sex, socioeconomic status is one of the most powerful determinants of health. We conducted a systematic review to examine the consistency and magnitude of the association between socioeconomic status and COPD health outcomes to determine the potential impact of SES disparity on the COPD population.

METHODS

Electronic databases to October 2011 were searched for studies of adults who had or were at risk for COPD that quantified an association between a measure of socioeconomic status and at least one COPD health outcome. Two authors independently reviewed studies, assessed study quality, and for eligible studies, extracted data.

RESULTS

Regardless of the population, socioeconomic status measure or COPD outcome examined, with few exceptions, consistent significant inverse associations between socioeconomic status and COPD outcomes were found. Most studies found that individuals of the lowest socioeconomic strata were at least twice as likely to have poor outcomes as those of the highest (range from no difference to 10-fold difference).

CONCLUSIONS

Social and economic disadvantage appears to have a significant consistent impact on COPD mortality and morbidity. These findings point to the need for public health strategies and research to address socioeconomic status disparity in individuals with COPD.

The Effects of the Health System Response to the COVID-19 Pandemic on Chronic Disease Management: A Narrative Review

BACKGROUND

Individuals with chronic conditions require ongoing disease management to reduce risks of adverse health outcomes. During the COVID-19 pandemic, health care for non-COVID-19 cases was affected due to the reallocation of resources towards urgent care for COVID-19 patients, resulting in inadequate ongoing care for chronic conditions.

METHODS

A keyword search was conducted in PubMed, Google Scholar, Science Direct, and Scopus for English language articles published between January 2020 and January 2021.

FINDINGS

During the COVID-19 pandemic, in-person care for individuals with chronic conditions have decreased due to government restriction of elective and non-urgent healthcare visits, greater instilled fear over potential COVID-19 exposure during in-person visits, and higher utilization rates of telemedicine compared to the pre-COVID-19 period. Potential benefits of a virtual-care framework during the pandemic include more effective routine disease monitoring, improved patient satisfaction, and increased treatment compliance and follow-up rates. However, more needs to be done to ensure timely and effective access to telemedicine, particularly for individuals with lower digital literacy. Capitation primary care models have been proposed as a more financially-robust approach during the COVID-19 pandemic than fee-for-service primary care models; however, the interplay between different primary models and the health outcomes is still poorly understood and warrants further investigation. Shortages of medication used to manage chronic conditions were also observed at the beginning of the COVID-19 pandemic due to global supply chain disruptions. Finally, patients with chronic conditions faced lifestyle disruptions due to the COVID-19 pandemic, specifically in physical activity, sleep, stress, and mental health, which need to be better addressed.

INTERPRETATION

Overall, this review elucidates the disproportionately greater barriers to primary and specialty care that patients with chronic diseases face during the COVID-19 pandemic and emphasizes the urgent need for better chronic disease management strategies moving forward.

Cardiovascular safety of inhaled long-acting bronchodilators in individuals with chronic obstructive pulmonary disease

IMPORTANCE

Chronic obstructive pulmonary disease (COPD) is a common and deadly disease. Long-acting inhaled β-agonists and anticholinergics, first-line medications for COPD, have been associated with increased risk of cardiovascular outcomes. When choosing between the medications, patients and physicians would benefit from knowing which has the least risk.

OBJECTIVE

To assess the association of these classes of medications with the risk of hospitalizations and emergency department visits for cardiovascular events.

DESIGN

We conducted a nested case-control analysis of a retrospective cohort study. We compared the risk of events between patients newly prescribed inhaled long-acting β-agonists and anticholinergics, after matching and adjusting for prognostic factors.

SETTING

Health care databases from Ontario, the largest province of Canada, with a multicultural population of approximately 13 million.

PARTICIPANTS

All individuals 66 years or older meeting a validated case definition of COPD, based on health administrative data, and treated for COPD from September 1, 2003, through March 31, 2009.

EXPOSURE

New use of an inhaled long-acting β-agonist or long-acting anticholinergic.

MAIN OUTCOME AND MEASURES

An emergency department visit or a hospitalization for a cardiovascular event.

RESULTS

Of 191 005 eligible patients, 53 532 (28.0%) had a hospitalization or an emergency department visit for a cardiovascular event. Newly prescribed long-acting inhaled β-agonists and anticholinergics were associated with a higher risk of an event compared with nonuse of those medications (respective adjusted odds ratios, 1.31 [95% CI, 1.12-1.52; P < .001] and 1.14 [1.01-1.28; P = .03]). We found no significant difference in events between the 2 medications (adjusted odds ratio of long-acting inhaled β-agonists compared with anticholinergics, 1.15 [95% CI, 0.95-1.38; P = .16]).

CONCLUSIONS AND RELEVANCE

Among older individuals with COPD, new use of long-acting β-agonists and anticholinergics is associated with similar increased risks of cardiovascular events. Close monitoring of COPD patients requiring long-acting bronchodilators is needed regardless of drug class.

Trends in chronic obstructive pulmonary disease prevalence, incidence, and mortality in ontario, Canada, 1996 to 2007: a population-based study

BACKGROUND

Chronic obstructive pulmonary disease (COPD) is a preventable and treatable disease with a prevalence of more than 10% worldwide among adults 40 years and older. Whether this amount has been increasing, decreasing, or stable over time remains unknown.

METHODS

A longitudinal cohort study using population-based, health administrative data from 1991 to 2007 was conducted in Ontario, Canada. Individuals with COPD were identified using a previously validated health administrative case definition of COPD. Annual COPD prevalence, incidence, and all-cause mortality rates were estimated from 1996 to 2007.

RESULTS

The prevalence of COPD increased by 64.8% between 1996 and 2007. The age- and sex-standardized COPD prevalence rate increased from 7.8% to 9.5%, representing a relative increase of 23.0% (P < .001). The age- and sex-standardized incidence decreased from 11.8 per 1000 adults to 8.5 per 1000 adults, representing a relative decrease of 28.3% (P < .001). Finally, the age- and sex-standardized all-cause mortality rate decreased from 5.7% to 4.3%, representing a relative decrease of 24.0% (P < .001).

CONCLUSIONS

Our findings indicate a substantial increase in COPD prevalence in the last decade, with more of the burden being shifted from men to women. Effective clinical and public health strategies are needed to prevent COPD and manage the increasing number of people living longer with this disease.

Proton pump inhibitors and the risk of hospitalisation for community-acquired pneumonia: replicated cohort studies with meta-analysis

OBJECTIVE

Previous observational studies suggest that the use of proton pump inhibitors (PPIs) may increase the risk of hospitalisation for community-acquired pneumonia (HCAP). However, the potential presence of confounding and protopathic biases limits the conclusions that can be drawn from these studies. Our objective was, therefore, to examine the risk of HCAP with PPIs prescribed prophylactically in new users of non-steroidal anti-inflammatory drugs (NSAIDs).

DESIGN

We formed eight restricted cohorts of new users of NSAIDs, aged ≥40 years, using a common protocol in eight databases (Alberta, Saskatchewan, Manitoba, Ontario, Quebec, Nova Scotia, US MarketScan and the UK's General Practice Research Database (GPRD)). This specific patient population was studied to minimise bias due to unmeasured confounders. High-dimensional propensity scores were used to estimate site-specific adjusted ORs (aORs) for HCAP at 6 months in PPI patients compared with unexposed patients. Fixed-effects meta-analytic models were used to estimate overall effects across databases.

RESULTS

Of the 4,238,504 new users of NSAIDs, 2.3% also started a PPI. The cumulative 6-month incidence of HCAP was 0.17% among patients prescribed PPIs and 0.12% in unexposed patients. After adjustment, PPIs were not associated with an increased risk of HCAP (aOR=1.05; 95% CI 0.89 to 1.25). Histamine-2 receptor antagonists yielded similar results (aOR=0.95, 95% CI 0.75 to 1.21).

CONCLUSIONS

Our study does not support the proposition of a pharmacological effect of gastric acid suppressors on the risk of HCAP.

Trends in asthma prevalence and incidence in Ontario, Canada, 1996-2005: a population study

In the 1980s and early 1990s, asthma prevalence increased significantly in most Westernized countries. In more recent years, asthma trends have been less clear, with some studies suggesting that they are still rising and others suggesting that they have stabilized or decreased. A population-based cohort study was conducted to estimate asthma prevalence and incidence trends in one large Canadian province, Ontario. All individuals with asthma living in Ontario, a province of Canada with a multicultural population of approximately 12 million, were identified in universal, population health administrative databases by using a validated health administrative case definition of asthma. Annual asthma prevalence, incidence, and all-cause mortality rates were estimated from 1996 to 2005. During this time, the prevalence of asthma increased by 70.5%. The age- and sex-standardized asthma prevalence increased from 8.5% in 1996 to 13.3% in 2005, a relative increase of 55.1% (P < 0.0001). Asthma incidence rates increased in children by 30.0% and were relatively stable in adults. Overall all-cause mortality decreased. Asthma prevalence in Ontario, Canada, has increased significantly. This is attributable, in part, to an increase in the incidence of asthma in children. Effective clinical and public health strategies are needed to prevent and manage asthma in the population.

The risk of mycobacterial infections associated with inhaled corticosteroid use

Inhaled corticosteroid (ICS) use is associated with an increased risk of pneumonia. This study was performed to determine if ICS use is associated with an increased risk of nontuberculous mycobacterial pulmonary disease (NTM-PD) or tuberculosis (TB).We conducted a population-based nested case-control study using linked laboratory and health administrative databases in Ontario, Canada, including adults aged ≥66 years with treated obstructive lung disease (i.e. asthma, chronic obstructive pulmonary disease (COPD) or asthma-COPD overlap syndrome) between 2001 and 2013. We estimated odds ratios comparing ICS use with nonuse among NTM-PD and TB cases and controls using conditional logistic regression.Among 417 494 older adults with treated obstructive lung disease, we identified 2966 cases of NTM-PD and 327 cases of TB. Current ICS use was associated with NTM-PD compared with nonuse (adjusted OR (aOR) 1.86, 95% CI 1.60-2.15) and was statistically significant for fluticasone (aOR 2.09, 95% CI 1.80-2.43), but not for budesonide (aOR 1.19, 95% CI 0.97-1.45). There was a strong dose-response relationship between incident NTM-PD and cumulative ICS dose over 1 year. There was no significant association between current ICS use and TB (aOR 1.43, 95% CI 0.95-2.16).This study suggests that ICS use is associated with an increased risk of NTM-PD, but not TB.

The impact of infection on population health: results of the Ontario burden of infectious diseases study

BACKGROUND

Evidence-based priority setting is increasingly important for rationally distributing scarce health resources and for guiding future health research. We sought to quantify the contribution of a wide range of infectious diseases to the overall infectious disease burden in a high-income setting.

METHODOLOGY/PRINCIPAL FINDINGS

We used health-adjusted life years (HALYs), a composite measure comprising premature mortality and reduced functioning due to disease, to estimate the burden of 51 infectious diseases and associated syndromes in Ontario using 2005-2007 data. Deaths were estimated from vital statistics data and disease incidence was estimated from reportable disease, healthcare utilization, and cancer registry data, supplemented by local modeling studies and national and international epidemiologic studies. The 51 infectious agents and associated syndromes accounted for 729 lost HALYs, 44.2 deaths, and 58,987 incident cases per 100,000 population annually. The most burdensome infectious agents were: hepatitis C virus, Streptococcus pneumoniae, Escherichia coli, human papillomavirus, hepatitis B virus, human immunodeficiency virus, Staphylococcus aureus, influenza virus, Clostridium difficile, and rhinovirus. The top five, ten, and 20 pathogens accounted for 46%, 67%, and 75% of the total infectious disease burden, respectively. Marked sex-specific differences in disease burden were observed for some pathogens. The main limitations of this study were the exclusion of certain infectious diseases due to data availability issues, not considering the impact of co-infections and co-morbidity, and the inability to assess the burden of milder infections that do not result in healthcare utilization.

CONCLUSIONS/SIGNIFICANCE

Infectious diseases continue to cause a substantial health burden in high-income settings such as Ontario. Most of this burden is attributable to a relatively small number of infectious agents, for which many effective interventions have been previously identified. Therefore, these findings should be used to guide public health policy, planning, and research.

Combination long-acting β-agonists and inhaled corticosteroids compared with long-acting β-agonists alone in older adults with chronic obstructive pulmonary disease

IMPORTANCE

Chronic obstructive pulmonary disease (COPD), a manageable respiratory condition, is the third leading cause of death worldwide. Knowing which prescription medications are the most effective in improving health outcomes for people with COPD is essential to maximizing health outcomes.

OBJECTIVE

To estimate the long-term benefits of combination long-acting β-agonists (LABAs) and inhaled corticosteroids compared with LABAs alone in a real-world setting.

DESIGN, SETTING, AND PATIENTS

Population-based, longitudinal cohort study conducted in Ontario, Canada, from 2003 to 2011. All individuals aged 66 years or older who met a validated case definition of COPD on the basis of health administrative data were included. After propensity score matching, there were 8712 new users of LABA-inhaled corticosteroid combination therapy and 3160 new users of LABAs alone who were followed up for median times of 2.7 years and 2.5 years, respectively.

EXPOSURES

Newly prescribed combination LABAs and inhaled corticosteroids or LABAs alone.

MAIN OUTCOMES AND MEASURES

Composite outcome of death and COPD hospitalization.

RESULTS

The main outcome was observed among 5594 new users of LABAs and inhaled corticosteroids (3174 deaths [36.4%]; 2420 COPD hospitalizations [27.8%]) and 2129 new users of LABAs alone (1179 deaths [37.3%]; 950 COPD hospitalizations [30.1%]). New use of LABAs and inhaled corticosteroids was associated with a modestly reduced risk of death or COPD hospitalization compared with new use of LABAs alone (difference in composite outcome at 5 years, -3.7%; 95% CI, -5.7% to -1.7%; hazard ratio [HR], 0.92; 95% CI, 0.88-0.96). The greatest difference was among COPD patients with a codiagnosis of asthma (difference in composite at 5 years, -6.5%; 95% CI, -10.3% to -2.7%; HR, 0.84; 95% CI, 0.77-0.91) and those who were not receiving inhaled long-acting anticholinergic medication (difference in composite at 5 years, -8.4%; 95% CI, -11.9% to -4.9%; HR, 0.79; 95% CI, 0.73-0.86).

CONCLUSIONS AND RELEVANCE

Among older adults with COPD, particularly those with asthma and those not receiving a long-acting anticholinergic medication, newly prescribed LABA and inhaled corticosteroid combination therapy, compared with newly prescribed LABAs alone, was associated with a significantly lower risk of the composite outcome of death or COPD hospitalization.

Obstructive sleep apnea and the prevalence and incidence of cancer

BACKGROUND

A link between obstructive sleep apnea and cancer development or progression has been suggested, possibly through chronic hypoxemia, but supporting evidence is limited. We examined the association between the severity of obstructive sleep apnea and prevalent and incident cancer, controlling for known risk factors for cancer development.

METHODS

We included all adults referred with possible obstructive sleep apnea who underwent a first diagnostic sleep study at a single large academic hospital between 1994 and 2010. We linked patient data with data from Ontario health administrative databases from 1991 to 2013. Cancer diagnosis was derived from the Ontario Cancer Registry. We assessed the cross-sectional association between obstructive sleep apnea and prevalent cancer at the time of the sleep study (baseline) using logistic regression analysis. Cox regression models were used to investigate the association between obstructive sleep apnea and incident cancer among patients free of cancer at baseline.

RESULTS

Of 10 149 patients who underwent a sleep study, 520 (5.1%) had a cancer diagnosis at baseline. Over a median follow-up of 7.8 years, 627 (6.5%) of the 9629 patients who were free of cancer at baseline had incident cancer. In multivariable regression models, the severity of sleep apnea was not significantly associated with either prevalent or incident cancer after adjustment for age, sex, body mass index and smoking status at baseline (apnea-hypopnea index > 30 v. < 5: adjusted odds ratio [OR] 0.96, 95% confidence interval [CI] 0.71-1.30, for prevalent cancer, and adjusted hazard ratio [HR] 1.02, 95% CI 0.80-1.31, for incident cancer; sleep time spent with oxygen saturation < 90%, per 10-minute increase: adjusted OR 1.01, 95% CI 1.00-1.03, for prevalent cancer, and adjusted HR 1.00, 95% CI 0.99-1.02, for incident cancer).

INTERPRETATION

In a large cohort, the severity of obstructive sleep apnea was not independently associated with either prevalent or incident cancer. Additional studies are needed to elucidate whether there is an independent association with specific types of cancer.

A new cervical spine clearance protocol using computed tomography

OBJECTIVE

The purpose of this study was to assess a cervical spine clearance protocol for blunt trauma patients using helical computed tomographic (CT) scan of the cervical spine (C-spine).

METHODS

A protocol using CT scan of the C-spine was implemented and the first 6 months of use reviewed. Patients requiring a CT scan of the head had the C-spine evaluated by lateral C-spine radiography and a helical CT scan. Patients without indication for CT scan of the head had the C-spine evaluated by three-view radiography (anteroposterior, lateral, and odontoid) with selective CT scan of the C-spine for imaging areas not well visualized or those with abnormalities identified by radiography or by clinical examination alone.

RESULTS

Three hundred twenty-four patients were admitted to the trauma center after blunt trauma during the first 6 months of protocol implementation. Head CT scans were obtained in 158 patients and lateral cervical spine radiography in conjunction with helical CT scanning evaluated the C-spine. The other 166 patients had the cervical spine cleared by three-view radiography series or by clinical examination alone. For patients in whom a head CT scan was not indicated, CT scanning was used only when plain radiographs failed to adequately visualize the entire C-spine. A total of 15 injuries (4.6% of the group) were detected. Seven injuries were suspected or detected by lateral plain radiographs and confirmed by CT scan. Six patients had an injury not detected by radiography but diagnosed by CT scan, and one patient had a false-positive radiograph. Of the remaining two injuries, one was diagnosed by magnetic resonance imaging and the other by CT scan outside of the protocol. Lateral plain radiographs alone failed to detect 46% (n = 6) of all injuries.

CONCLUSION

In our series, the selective use of helical CT scanning with plain radiography increased the accuracy with which cervical spine injury was detected from 54% to 100%. The protocol allowed for more rapid evaluation in many patients as well. We recommend that practice guidelines include the use of helical CT scan of the entire C-spine as the diagnostic procedure for those blunt trauma patients undergoing CT scanning of the head.

Reactivated and latent varicella-zoster virus in human dorsal root ganglia

Ganglia obtained at autopsy were examined by in situ hybridization from one patient with zoster (also called herpes zoster or shingles), two varicella-zoster virus (VZV)-seropositive patients with clinical evidence of zoster, one VZV-seronegative child, and one fetus. Ganglia positive for VZV had a hybridization signal in both neuronal and nonneuronal satellite cells. Ganglia obtained from the fetus and from the seronegative infant were consistently negative for VZV. Two striking observations were evident regarding the presence of VZV DNA in ganglia obtained from the individual with zoster at the time of death. First, ganglia innervating the sites of reactivation and ganglia innervating adjacent sites yielded strongly positive signals in neurons and satellite cells, whereas ganglia from distant sites were rarely positive. Second, VZV DNA was found in both the nuclei and the cytoplasm of neurons innervating areas of zoster. However, in neurons innervating zoster-free areas, VZV DNA was found only in the nucleus of neurons and their supporting satellite cells. Immunohistochemistry with a fluorescent monoclonal antibody to the VZV glycoprotein gpI, a late virus protein, revealed a positive signal in the cytoplasm of ganglia with clinical evidence of reactivation. These results illustrate that both neuronal and satellite cells become latently infected following primary VZV infection. The presence of VZV DNA and gpI in the cytoplasm of neurons demonstrates productive infection following reactivation at the site of latency.