Jacqueline Simatovic

Progression from Asthma to Chronic Obstructive Pulmonary Disease. Is Air Pollution a Risk Factor

RATIONALE Individuals with asthma-chronic obstructive pulmonary disease (COPD) overlap syndrome (ACOS), have more rapid decline in lung function, more frequent exacerbations, and poorer quality of life than those with asthma or COPD alone. Air pollution exposure is a known risk factor for asthma and COPD; however, its role in ACOS is not as well understood. OBJECTIVES To determine if individuals with asthma exposed to higher levels of air pollution have an increased risk of ACOS. METHODS Individuals who resided in Ontario, Canada, aged 18 years or older in 1996 with incident asthma between 1996 and 2009 who participated in the Canadian Community Health Survey were identified and followed until 2014 to determine the development of ACOS. Data on exposures to fine particulate matter (PM2.5) and ozone (O3) were obtained from fixed monitoring sites. Associations between air pollutants and ACOS were evaluated using Cox regression models. MEASUREMENTS AND MAIN RESULTS Of the 6,040 adults with incident asthma who completed the Canadian Community Health Survey, 630 were identified as ACOS cases. Compared with those without ACOS, the ACOS population had later onset of asthma, higher proportion of mortality, and more frequent emergency department visits before COPD diagnosis. The adjusted hazard ratios of ACOS and cumulative exposures to PM2.5 (per 10 μg/m(3)) and O3 (per 10 ppb) were 2.78 (95% confidence interval, 1.62-4.78) and 1.31 (95% confidence interval, 0.71-2.39), respectively. CONCLUSIONS Individuals exposed to higher levels of air pollution had nearly threefold greater odds of developing ACOS. Minimizing exposure to high levels of air pollution may decrease the risk of ACOS.

Chronic disease prevalence in women and air pollution — A 30-year longitudinal cohort study

BACKGROUND Air pollution, such as fine particulate matter (PM2.5), can increase risk of adverse health events among people with heart disease, diabetes, asthma and chronic obstructive pulmonary disease (COPD) by aggravating these conditions. Identifying the influence of PM2.5 on prevalence of these conditions may help target interventions to reduce disease morbidity among high-risk populations. OBJECTIVES The objective of this study is to measure the association of exposure of PM2.5 with prevalence risk of various chronic diseases among a longitudinal cohort of women. METHODS Women from Ontario who enrolled in the Canadian National Breast Screening Study (CNBSS) from 1980 to 1985 (n = 29,549) were linked to provincial health administrative data from April 1, 1992 to March 31, 2013 to determine the prevalence of major chronic disease and conditions (heart disease, diabetes, asthma, COPD, acute myocardial infarction, angina, stroke and cancers). Exposure to PM2.5 was measured using satellite data collected from January 1, 1998 to December 31, 2006 and assigned to resident postal-code at time of entry into study. Poisson regression models were used to describe the relationship between exposure to ambient PM2.5 and chronic disease prevalence. Prevalence rate ratios (PRs) were estimated while adjusting for potential confounders: baseline age, smoking, BMI, marital status, education and occupation. Separate models were run for each chronic disease and condition. RESULTS Congestive heart failure (PR = 1.31, 95% CI: 1.13, 1.51), diabetes (PR = 1.28, 95% CI: 1.16, 1.41), ischemic heart disease (PR = 1.22, 95% CI: 1.14, 1.30), and stroke (PR = 1.21, 95% CI: 1.09, 1.35) showed over a 20% increase in PRs per 10 μg/m(3) increase in PM2.5 after adjusting for risk factors. Risks were elevated in smokers and those with BMI greater than 30. CONCLUSIONS This study estimated significant elevated prevalent rate ratios per unit increase in PM2.5 in nine of the ten chronic diseases studied.

Asthma Deaths in a Large Provincial Health System. A 10-Year Population-Based Study

RATIONALE Individuals with asthma are more likely to die from chronic conditions than the general population. Measuring only mortality with asthma listed as the primary cause of death may lead to an underestimation of total asthma mortality. OBJECTIVES To examine mortality patterns in the asthma population over 10 years, including asthma as the primary cause of death (asthma-specific mortality) and asthma as a secondary, contributing cause of death (asthma-contributing mortality). METHODS Health administrative data from Ontario, Canada were used to identify mortality rates and cause of death in subjects 0 to 99 years of age. Mortality rates were calculated in the asthma and general population from 1999 to 2008. Total asthma mortality was estimated by adding rates of asthma-specific and asthma-contributing mortality for years 2003 to 2008. MEASUREMENTS AND MAIN RESULTS Asthma-specific mortality rates per 100,000 asthma population decreased by 54.4% from 13.6 in 1999 to 6.2 in 2008. In 2008, the asthma population had higher all-cause mortality compared with the general population (rate ratio, 1.3), asthma-specific mortality rates were 60% higher among those in the lowest compared with highest socioeconomic status, and total asthma mortality was fourfold higher than asthma-specific mortality alone (21.6 vs. 5.4 per 100,000). CONCLUSIONS All-cause mortality rates have decreased substantially over the past decade. Compared with the general population, the asthma population has higher all-cause mortality and is more likely to die from comorbid conditions. Total asthma mortality was fourfold higher than asthma-specific mortality, highlighting the importance of comprehensive measurement approaches that include asthma-specific and asthma-contributing mortality.

Health risk of air pollution on people living with major chronic diseases: a Canadian population-based study.

Objectives The objective of this study was to use health administrative and environmental data to quantify the effects of ambient air pollution on health service use among those with chronic diseases. We hypothesised that health service use would be higher among those with more exposure to air pollution as measured by the Air Quality Health Index (AQHI). Setting Health administrative data was used to quantify health service use at the primary (physician office visits) and secondary (emergency department visits, hospitalisations) level of care in Ontario, Canada. Participants We included individuals who resided in Ontario, Canada, from 2003 to 2010, who were ever diagnosed with one of 11 major chronic diseases. Outcome measures Rate ratios (RR) from Poisson regression models were used to estimate the short-term impact of incremental unit increases in AQHI, nitrogen dioxide (NO2; 10 ppb), fine particulate matter (PM2.5; 10 µg/m3) and ozone (O3; 10 ppb) on health services use among individuals with each disease. We adjusted for age, sex, day of the week, temperature, season, year, socioeconomic status and region of residence. Results Increases in outpatient visits ranged from 1% to 5% for every unit increase in the 10-point AQHI scale, corresponding to an increase of about 15 000 outpatient visits on a day with poor versus good air quality. The greatest increases in outpatient visits were for individuals with non-lung cancers (AQHI:RR=1.05; NO2:RR=1.14; p<0.0001) and COPD (AQHI:RR=1.05; NO2:RR=1.12; p<0.0001) and in hospitalisations, for individuals with diabetes (AQHI:RR=1.04; NO2:RR=1.07; p<0.0001) and COPD (AQHI:RR=1.03; NO2:RR=1.09; p<1.001). The impact remained 2 days after peak AQHI levels. Conclusions Among individuals with chronic diseases, health service use increased with higher levels of exposure to air pollution, as measured by the AQHI. Future research would do well to measure the utility of targeted air quality advisories based on the AQHI to reduce associated health service use.

Quality of asthma care under different primary care models in Canada: a population-based study

BackgroundPrevious research has shown variations in quality of care and patient outcomes under different primary care models. The objective of this study was to use previously validated, evidence-based performance indicators to measure quality of asthma care over time and to compare quality of care between different primary care models.MethodsData were obtained for years 2006 to 2010 from the Ontario Asthma Surveillance Information System, which uses health administrative databases to track individuals with asthma living in the province of Ontario, Canada. Individuals with asthma (n=1,813,922) were divided into groups based on the practice model of their primary care provider (i.e., fee-for-service, blended fee-for-service, blended capitation). Quality of asthma care was measured using six validated, evidence-based asthma care performance indicators.ResultsAll of the asthma performance indicators improved over time within each of the primary care models. Compared to the traditional fee-for-service model, the blended fee-for-service and blended capitation models had higher use of spirometry for asthma diagnosis and monitoring, higher rates of inhaled corticosteroid prescription, and lower outpatient claims. Emergency department visits were lowest in the blended fee-for-service group.ConclusionsQuality of asthma care improved over time within each of the primary care models. However, the amount by which they improved differed between the models. The newer primary care models (i.e., blended fee-for-service, blended capitation) appear to provide better quality of asthma care compared to the traditional fee-for-service model.

Characteristics of Individuals Admitted to the Intensive Care Unit for Asthma

Introduction: While asthma mortality and hospitalizations have decreased substantially over the past two decades, asthma prevalence has increased, and a number of individuals still present with severe asthma. As intensive care unit (ICU) admissions can be used as a marker for severe asthma, there is utility in continuing to monitor ICU trends and the descriptive profile of individuals admitted to the ICU. Methods: Health administrative population data from Ontario, Canada, were used to describe ICU admission trends by age group from 2003 to 2012 and the characteristics of those admitted to ICU. Descriptive analyses were performed for both hospitalized patients and ICU patients for age, sex, rurality, neighborhood income quintile and comorbidities. Results: ICU admission rates per 100,000 asthma population decreased steadily over time (56.4 in 2003; 31.1 in 2012), but increased in the 0-4 (73.9 in 2003; 85.9 in 2012) and 5-14 (11.1 in 2003; 18.8 in 2012) age groups. Compared to individuals who were hospitalized only, a greater proportion of older individuals, females, children with other respiratory conditions, and adults with acute myocardial infarction were admitted to the ICU. Conclusions: While the overall rate of ICU admissions has decreased over time, it has increased in children aged 0-14. This study identified high risk groups who are more likely to be admitted to the ICU. These individuals may benefit from targeted interventions to improve asthma control and reduce their future risk of admission to the ICU.

Frequency of health service use in the year prior to asthma death

Abstract Objective: High frequency health service use (HSU) is associated with poorly controlled asthma, and is a recognized risk factor for near-fatal or fatal asthma. The objective of this study was to describe the frequency of HSU in the year prior to asthma death. Methods: Individuals aged 0–99 years who died from asthma from April 1996 to December 2011 in Ontario, Canada were identified as cases. Cases were matched to 4–5 live asthma controls by age, sex, rural/urban residence, socioeconomic status, duration of asthma and a co-diagnosis of COPD. HSU records in the year prior to death [hospitalization, emergency department (ED) and outpatient visits] were assembled. The association of prior HSU and asthma death was measured by conditional logistic regression models. Results: From 1996 to 2011, 1503 individuals died from asthma. While the majority of cases did not have increased HSU as defined in the study, compared to matched live asthma controls, the cases were 8-fold more likely to have been hospitalized two or more times (OR = 7.60; 95% CI: 4.90, 11.77), 13-fold more likely to have had three or more ED visits (OR = 13.28; 95% CI: 7.55, 23.34) and 4-fold more likely to have had five or more physician visits for asthma (OR = 4.41; 95% CI: 3.58, 5.42). Conclusions: Frequency of HSU in the year prior was substantially higher in those died from asthma. Specifically, more than one asthma hospital admission, three ED visits or five physician visits increased the asthma mortality risk substantially and exponentially.

Estimating the impact of temperature and air pollution on cardiopulmonary and diabetic health during the TORONTO 2015 Pan Am/Parapan Am Games

Methods Exposure data (temperature, humidity and air pollution) were obtained from Environment Canada for years 2003 to 2010. Using ArcGIS, the geospatial patterns of exposures were described for regions of Ontario hosting Pan Am events. A linear trend was used to forecast expected exposures for Pan Am regions in July 2015. Health outcomes (hospitalizations, emergency department visits and outpatient claims) for all-cause morbidity, asthma, asthma-related conditions, diabetes and hypertension were measured using data provided by the Institute for Clinical Evaluative Sciences. Associations between exposures and health outcomes were obtained from regression models. Health outcomes were predicted for July 2015 using scenarios of 5% and 10% higher exposure levels than forecasted.

Estimating Toronto’s health services use for the 2015 Pan American and Parapan American Games

Aims: Ambient air temperature may exacerbate the burden of chronic diseases on Ontario’s healthcare system during mass gathering events. This study aimed to estimate the impact of increasing temperature in July and August on health services use for chronic conditions in Ontario’s Golden Horseshoe region during the 2015 Pan American and Parapan American Games, using environmental and health administrative data from previous years. Method: Negative binomial regression was used to calculate incidence risk ratios for same-day health services use (hospitalisations, emergency department visits, physician office visits) for all causes, asthma, asthma-related conditions, diabetes and hypertension associated with unit increases in daily maximum temperature from 1 May to 31 August in 2008–2010. Sensitivity analysis was performed to estimate the added burden of an increased population size, in order to model an influx of visitors during the Games. Results: In July and August, on days with daily maximum temperatures of 35°C compared to 25°C, we estimated seeing 7,827 more physician office visits for all causes in Ontario’s Golden Horseshoe region. The estimated relative increase in physician office visits for diabetes due to temperature alone was 8.4%. With an estimated 10% increase in population, the increase in physician office visits for all causes tripled to an estimated 23,590. Conclusion: Temperature was identified as a potential contributor to greater health services use during the Games, particularly for those living with diabetes. These results highlight the importance of strategic delivery of health services during mass gathering events, and suggest a role for educating at-risk individuals on prevention behaviours, particularly on very hot days.

Impact of air pollution on physician office visits for common childhood conditions in Ontario, Canada

Methods PM2.5 and temperature measurements were obtained from satellite data for all of Ontario [2]. Physician office visits were stratified into two groups based on the literature: air pollution-sensitive (acute respiratory infections, allergic rhinitis, asthma, bronchiolitis, diabetes, otitis media) and air pollution-insensitive (gastroenteritis, injuries). Claims data were obtained for every month in 2010 from health administrative databases for children 0-14 years of age. Ageand sex-standardized morbidity ratios (SMRs) were calculated by region in Ontario. Spatial Poisson regression models were used to analyze the relationship between PM2.5 and physician office visits, with temperature as a covariate. Results Crude rates of physician office visits are presented in Table 1. As expected, fine particulate was significantly associated with monthly rates of physician office visits for air pollution-sensitive conditions, and not for insensitive conditions. Fitted SMRs for air pollution-sensitive conditions are presented in Figure 1. SMRs for sensitive and insensitive conditions were strongly positively correlated (r = 0.53), and data were spatially autocorrelated. This suggests an underlying spatial process that influences physician office visit rates for common childhood conditions, both for air pollution-sensitive and -insensitive conditions.