The influence of sensitisation to pollens and moulds on seasonal variations in asthma attacks.

No large study has described the seasonal variation in asthma attacks in population-based asthmatics in whom sensitisation to allergen has been measured. 2,637 young adults with asthma living in 15 countries reported the months in which they usually had attacks of asthma and had skin-prick tests performed. Differences in seasonal patterns by sensitisation status were assessed using generalised estimating equations.

A population-based study of tuberculosis epidemiology and innovative service delivery in Canada.

Objective: To compare and interpret tuberculosis (TB) incidence rates in a Canadian population across two decennials (1989-1998 and 1999-2008) as a benchmark for World Health Organization targets and the long-term goal of TB elimination. The population under study was served by two urban clinics in the first decennial and two urban and one provincial clinic in the second.

Methods: TB rates among Status Indians, Canadian-born 'others' and the foreign-born were estimated using provincial and national databases.

CO(2) inhalation as a treatment for apnea of prematurity: a randomized double-blind controlled trial.

Objective: To compare the effect of prolonged inhalation of a low concentration of CO(2) with theophylline for the treatment of apnea of prematurity.

Study Design: Prospective, randomized, double-blind controlled trial of 87 preterm infants with apnea of prematurity (27-32 weeks' gestational age) assigned to either theophylline plus 0.5 L/min of room air via nasal prongs or placebo plus 0.

The tuberculin skin test is unreliable in school children BCG-vaccinated in infancy and at low risk of tuberculosis infection.

Background: The tuberculin skin test (TST) is often used to screen for latent tuberculosis infection (LTBI) in school children, many of whom were bacille Calmette-Guérin (BCG)-vaccinated in infancy. The reliability of the TST in such children is unknown.

Methods: TSTs performed in low-risk BCG-vaccinated and -nonvaccinated grade 1 and grade 6 First Nations (North American Indian) school children in the province of Alberta, Canada, were evaluated retrospectively.

Piecing the puzzle together: foreign-born tuberculosis in an immigrant-receiving country.

In major immigrant-receiving countries, annual foreign-born tuberculosis (TB) case counts and rates are relatively constant. Why this is so, and who might be a high-yield target for screening for latent TB infection, remain open questions. Foreign-born TB in Canada during 1986-2002 was retrospectively examined using national TB and immigration data as well as census data.

Geographical variations in the prevalence of atopic sensitization in six study sites across Canada.

Background: Geographical variations in atopic sensitization in Canada have not been described previously. This study used the standardized protocol of the European Community Respiratory Health Survey-1 (ECRHS-1) to investigate the distribution and predictors of atopic sensitization in six sites across Canada and to compare the results with some ECRHS-1 centers.

Methods: Adults aged 20-44 years in six study sites across Canada underwent allergy skin testing using 14 allergens (Dermatophagoides pteronyssinus, Dermatophagoides farinae) cat, cockroach, grasses (Timothy grass, Kentucky grass), molds (Cladosporium herbarium, Alternaria alternata, Aspergillus fumigatus, Penicillium), trees (tree mix, birch, Olea europea), and common ragweed.

The feasibility of using an 'opt-out' approach to achieve universal HIV testing of tuberculosis patients in Alberta.

Objective: Universal HIV testing of tuberculosis (TB) patients, defined as testing greater than 80% of incident cases, has been recommended but not achieved in Canada. The objectives of this study were: i) to assess the success of an 'opt-out' approach, whereby HIV testing is routine unless the patient specifically chooses otherwise, and ii) to determine the risk factors for HIV in patients tested before and after this approach was implemented.

Methods: TB and HIV databases in the province of Alberta were cross-matched before HAART (highly active anti-retroviral therapy) was available (1991-1997), after HAART but before 'opt-out' testing was implemented (1998-2002), and after 'opt-out' testing was implemented (2003-2006), and the HIV status of TB patients in each time period was described.

Empirical treatment of community-acquired pneumonia and the development of fluoroquinolone-resistant tuberculosis.

Unlabelled: BACKGROUND" Fluoroquinolone (FLQ) antibiotics are not uncommonly prescribed for community-acquired pneumonia that is later proven to be pulmonary tuberculosis (TB). Such FLQ monotherapy may result in FLQ-resistant pulmonary TB.

Methods: To assess outpatient FLQ use by patients with culture-proven pulmonary TB before diagnosis, TB registries in Alberta and Saskatchewan, Canada, were linked with provincial and federal drug benefit plans.

A randomized controlled trial of theophylline versus CO2 inhalation for treating apnea of prematurity.

Objective: To determine whether inhalation of 0.8% CO(2) in preterm infants decreases the duration and rate of apnea as effectively as or better than theophylline with fewer adverse side effects.

Study Design: A prospective, randomized, control study of 42 preterm infants of gestational age 27 to 32 weeks assigned to receive inhaled CO(2) (n = 21) or theophylline (n = 21).

Cardiovascular morbidity and the use of inhaled bronchodilators.

We used the Manitoba Health database to examine the relationship between use of inhaled respiratory drugs in people with chronic obstructive respiratory diseases and cardiovascular hospitalizations from 1996 through 2000. The drugs examined were beta agonists [BA], ipratropium bromide IB, and inhaled steroids (ICS). End points were first hospitalizations for supraventricular tachycardia, myocardial infarction, heart failure or stroke.

Prevalence of asthma symptoms in 7th- and 8th-grade school children in a rural region in India.

Unlabelled: We estimated the prevalence of asthma related symptoms in grade 7 and 8 students in a rural region in India.

Method: An International Study of Asthma and Allergies in Childhood (ISAAC), questionnaire with added questions related to environmental and familial exposures, was administered to 3668 students from 48 rural schools near Malegaon, India.

Results: A history of asthma was present in 10.

Pediatric tuberculosis in Alberta: epidemiology and case characteristics (1990-2004).

Background: Pediatric tuberculosis (TB) is important medically and indicative of a public health problem. An understanding of the epidemiology and case characteristics of pediatric TB, in a province that accepts large numbers of immigrants, can inform TB elimination strategy.

Methods: All cases of pediatric TB notified in Alberta between 1990 and 2004 were identified in the TB Registry.

Airflow obstruction in young adults in Canada.

Objective: Airflow obstruction is relatively uncommon in young adults, and may indicate potential for the development of progressive disease. The objective of the present study was to enumerate and characterize airflow obstruction in a random sample of Canadians aged 20 to 44 years.

Setting: The sample (n=2962) was drawn from six Canadian sites.

Mycobacterium tuberculosis infection in First Nations preschool children in Alberta: implications for BCG (bacille Calmette-Guérin) vaccine withdrawal.

Background: On April 1, 2004, BCG (bacille Calmette-Guérin), a tuberculosis (TB) control vaccine, was discontinued in all but four high-risk communities in Alberta. To confirm the safety of vaccine withdrawal, and for future planning, the annual risk of infection (ARI) was determined in preschool First Nations children.

Methods: First Nations children born into reserve communities in Alberta between April 1, 1998 and March 31, 2004, and still living on reserve in 2004-2005, were identified.

Relationship of early childhood viral exposures to respiratory symptoms, onset of possible asthma and atopy in high risk children: the Canadian Asthma Primary Prevention Study.

The contribution of respiratory viral infections to the onset of asthma and atopy is controversial. In "high risk" children (n = 455) born into asthmatic/atopic families, we determined the relationship of exposures to common respiratory viruses and concomitant respiratory symptoms, and to subsequent possible asthma and atopy at ages 1 and 2 years. Frozen nasal specimens, obtained when children were 2 weeks, 4, 8, and 12 months old, underwent reverse transcription-polymerase chain reaction (RT-PCR) testing for parainfluenza virus (PIV), respiratory syncytial virus (RSV), and picornavirus (rhinovirus/enterovirus).

Healthcare utilization in women with obstructive sleep apnea syndrome 2 years after diagnosis and treatment.

Unlabelled: SUBJECTIVE OBJECTIVES: To document healthcare utilization 2 years after diagnosis in women with obstructive sleep apnea syndrome (OSAS).

Design: Retrospective observational cohort study.

Setting: Tertiary university-based medical center.

Inhaled corticosteroids and mortality in COPD.

Study Objectives: To assess the influence of inhaled corticosteroids (ICSs) on mortality in COPD patients, which is currently a controversial topic.

Setting: Manitoba Health maintains a population-wide research database that includes pharmaceutical information.

Design And Patients: We examined mortality in people 90 to 365 days after hospital discharge for COPD, comparing those persons who received inhaled steroids within 90 days of hospital discharge with those who did not.

Introduction of leukotriene receptor antagonists in Manitoba.

Patient characteristics and prescribing patterns during the introduction of leukotriene receptor antagonists (LTRA) in Manitoba are described using the provincial health database. Residents of Manitoba with asthma, chronic obstructive pulmonary disease, bronchitis or claims for respiratory medications were identified. Six thousand forty-one of 160,626 (3.

Physician-diagnosed asthma and allergic rhinitis in Manitoba: 1985-1998.

Background: A worldwide increase has been noted in the prevalence of asthma, but the data for other allergic disorders are less consistent.

Objective: To study 14-year trends in utilization of physician resources for asthma and compare them to trends for allergic rhinitis.

Methods: We studied visits to physicians by Manitoba residents for asthma (International Classification of Diseases, Ninth Revision, Clinical Modification [ICD-9-CM] code 493) and allergic rhinitis (ICD-9 code 477) between 1985 and 1998.

Utilization of healthcare resources in obstructive sleep apnea syndrome: a 5-year follow-up study in men using CPAP.

Study Objectives: Patients with untreated obstructive sleep apnea syndrome (OSAS) have higher healthcare utilization than matched controls. However, the long-term impact of continuous positive airway pressure (CPAP) use on healthcare utilization is unknown.

Design: Retrospective observational cohort study.

Estimating the incidence of dementia: the impact of adjusting for subject attrition using health care utilization data.

Purpose: To estimate incidence rates for dementia and the impact of subject attrition on these rates.

Methods: Crude, age- and gender-specific incidence rates of dementia and Alzheimer's disease were calculated using person-years analysis and Cox proportional hazard models in a population-based cohort study of 1952 adults aged 65+ years in Manitoba, Canada. Rates were standardized to the nondemented population using the direct method.

Latitude, birth date, and allergy.

Background: The space and time distribution of risk factors for allergic diseases may provide insights into disease mechanisms. Allergy is believed to vary by month of birth, but multinational studies taking into account latitude have not been conducted.

Methods And Findings: A questionnaire was distributed in 54 centres to a representative sample of 20- to 44-y-old men and women mainly in Europe but also including regions in North Africa, India, North America, Australia, and New Zealand.

Use of spirometry and respiratory drugs in Manitobans over 35 years of age with obstructive lung diseases.

Background: Previous data indicated that spirometry was underused in people with obstructive disease, especially those with chronic obstructive pulmonary disease (COPD).

Objective: To examine the use of respiratory drugs in patients with COPD and asthma, and to relate drug use to spirometry.

Methods: Manitoba Health maintains a database of physician services remunerated by fees that includes spirometry.

The effects of a smoking cessation intervention on 14.5-year mortality: a randomized clinical trial.

Background: Randomized clinical trials have not yet demonstrated the mortality benefit of smoking cessation.

Objective: To assess the long-term effect on mortality of a randomly applied smoking cessation program.

Design: The Lung Health Study was a randomized clinical trial of smoking cessation.

Transmission characteristics of tuberculosis in the foreign-born and the Canadian-born populations of Alberta, Canada.

Setting: All notified cases of tuberculosis in the province of Alberta, Canada, 1994-1998.

Objective: To compare the transmission characteristics of tuberculosis among foreign-born and Canadian-born cases.

Design: Retrospective analysis using DNA fingerprinting (IS6110 restriction fragment length polymorphism and spoligotyping) and patient information from the Alberta Tuberculosis Registry.