Mieczysław Szyszkowicz

Publications of Mieczysław Szyszkowicz

• Ambient Sulphur Dioxide and Female ED Visits for Migraine.

  Authors: Mieczysław Szyszkowicz, Eugeniusz Porada

  ISRN neurology. 01/2012; 2012:279051.

  Ambient sulphur dioxide (SO(2)) concentrations may affect the number of female emergency department (ED) visits for migraine. ED visits diagnosed as migraine among females in two cities in Canada,Ambient sulphur dioxide (SO(2)) concentrations may affect the number of female emergency department (ED) visits for migraine. ED visits diagnosed as migraine among females in two cities in Canada, Toronto (N = 704) and Ottawa (N = 3, 358), were analyzed. In the study case-crossover design was used. Conditional logistic regression was realized to estimate odds ratios (ORs) and their 95% confidence intervals (CIs) relative to an increase in an interquartile range (IQR, in Toronto IQR = 2.9 ppb, in Ottawa IQR = 3.9 ppb) of sulphur dioxide. In the constructed conditional logistic regression models, temperature and relative humidity were adjusted in the form of natural splines. In Toronto positive and statistically significant associations of sulphur dioxide with migraine ED visits were obtained: all ages, OR = 1.04 (95% CI: 1.00, 1.08); age group [15, 50], OR = 1.05 (95% CI: 1.01, 1.09). In Ottawa positive correlations were observed: all ages, OR = 1.05 (95% CI: 0.97, 1.13); age group [15, 50], OR = 1.06 (95% CI: 0.97, 1.15). The results suggest that female migraine may be affected by ambient sulphur dioxide.

• Sulfur dioxide and emergency department visits for stroke and seizure.

  Authors: Mieczysław Szyszkowicz, Eugeniusz Porada, Neil Tremblay, Eric Grafstein

  Stroke research and treatment. 01/2012; 2012:824724.

  The purpose of this study was to assess an association between ambient sulfur dioxide and the number of emergency department (ED) visits for ischemic stroke and seizure. The study used data collectedThe purpose of this study was to assess an association between ambient sulfur dioxide and the number of emergency department (ED) visits for ischemic stroke and seizure. The study used data collected in a Vancouver (Canada) hospital in the years 1999-2003. Daily ED visits diagnosed as ministroke, stroke, or seizure were investigated using the case-crossover technique. Conditional logistic regression models were applied to estimate the odds ratios (ORs) and their respective 95% confidence intervals (CIs). The models included temperature and relative humidity in the form of natural splines. The results were reported for an increase in interquartile range ((IQR), IQR = 1.9 ppb for SO(2)). Positive and statistically significant associations were obtained for SO(2) and ischemic stroke for all patients (OR = 1.12; CI 1.02, 1.23; lag 3) and for female patients (OR = 1.17; CI 1.01, 1.33; lag 0). In the case of ED visits for seizure, for female patients the results were also statistically significant (OR = 1.15; CI 1.02, 1.28; lag 1 and OR = 1.18; CI 1.05, 1.32; lag 2). These findings suggest that cases of ischemic cerebrovascular accidents are associated with acute exposure to ambient sulfur dioxide.

• Even Low Levels of Ambient Air Pollutants Are Associated With Increased Emergency Department Visits for Hypertension.

  Authors: Mieczysław Szyszkowicz, Brian H Rowe, Robert D Brook

  The Canadian journal of cardiology. 09/2011;

  BACKGROUND: Numerous studies have reported associations between air pollution and cardiovascular diseases. While several studies illustrate that exposures to air pollutants can elevate bloodBACKGROUND: Numerous studies have reported associations between air pollution and cardiovascular diseases. While several studies illustrate that exposures to air pollutants can elevate blood pressure, few have evaluated the clinical relevance of this relationship. Hence, we aimed to explore the associations between daily concentrations of several air pollutants and emergency department visits for hypertension. METHODS: Odds ratios (ORs) for emergency department visits for hypertension in Edmonton, Canada, from April 1992 to March 2002 were associated with pollutant levels (CO, NO(2), SO(2), O(3), and particulate matter [PM] < 10 microns [PM(10)] and < 2.5 microns [PM(2.5)] in aerodynamic diameter, respectively) by means of a case-crossover technique with time-stratified strategy to define controls. The analysis was performed for all (N = 5365), male (N = 2069), and female (N = 3296) patients and for six air pollutants lagged by 0 to 9 days. ORs and their 95% confidence intervals (CIs) were reported for an increase in an interquartile range (IQR) for each pollutant. RESULTS: We observed associations for all patients and levels of NO(2) (IQR = 12.8 parts per billion; OR, 1.06; 95% CI, 1.00-1.12), SO(2) (IQR = 2.3 parts per billion; OR, 1.04; 95% CI, 1.00-1.08), and PM(10) (IQR = 15.0 μg/m(3); OR, 1.06; 95% CI, 1.01-1.11) for lag day 3, as well as for PM(10) (IQR = 15.0 μg/m(3); OR, 1.06; 95% CI, 1.01-1.11) and PM(2.5) (IQR = 6.2 μg/m(3); OR, 1.07; 95% CI, 1.01-1.11) for lag day 6. CONCLUSIONS: These findings support the contention that ambient pollution can produce clinically meaningful increases in blood pressure.

• Case-crossover design: air pollution and health outcomes.

  Authors: Mieczysław Szyszkowicz, Neil Tremblay

  International journal of occupational medicine and environmental health. 09/2011; 24(3):249-55.

  The objective of this study was to investigate variants of case-crossover design for assessing correlations between counts of health events over time and exposure to ambient air pollution. ForThe objective of this study was to investigate variants of case-crossover design for assessing correlations between counts of health events over time and exposure to ambient air pollution. For illustrative purposes, daily emergency department (ED) visits for depression among females were considered. Ambient nitrogen dioxide (NO(2)) was used as a principal ambient air pollutant. In addition, sulphur dioxide (SO(2)) and carbon monoxide (CO) were considered. Different configurations of the control periods (every 1, 2, …, 10 days) and different forms (linear, natural splines) of meteorological factors in the applied conditional logistic regression models were used. The sequence of overlapping age intervals was defined ([0, 19], [1, 20], and so on) and each age group was analyzed separately. The results for the defined age sequences allow identifying age ranges in which the effects are strongest. Consequently, for example, different age ranges for patients for which ED visits for depression were correlated with NO(2) and SO(2) were identified. This age-interval difference explains the very often observed phenomenon whereby two air pollutants used in one model may not show correlations with health outcomes. In this situation they affect separate age groups. The results also show dependency on number-defined control periods for the applied case-crossover technique. The opposite statistical conclusions may be generated by using different control schemas. The results support the hypothesis that ED visits for depressive disorder may be correlated with exposure to ambient air pollution.

• Ambient ozone and emergency department visits for cellulitis.

  Authors: Mieczysław Szyszkowicz, Eugeniusz Porada, Gilaad G Kaplan, Brian H Rowe

  International journal of environmental research and public health. 11/2010; 7(11):4078-88.

  Objectives were to assess and estimate an association between exposure to ground-level ozone and emergency department (ED) visits for cellulitis. All ED visits for cellulitis in Edmonton, Canada, inObjectives were to assess and estimate an association between exposure to ground-level ozone and emergency department (ED) visits for cellulitis. All ED visits for cellulitis in Edmonton, Canada, in the period April 1992-March 2002 (N = 69,547) were examined. Case-crossover design was applied to estimate odds ratio (OR, and 95% confidence interval) per one interquartile range (IQR) increase in ozone concentration (IQR = 14.0 ppb). Delay of ED visit relating to exposure was probed using 0- to 5-day exposure lags. For all patients in the all months (January-December) and lags 0 to 2 days, OR = 1.05 (1.02, 1.07). For male patients during the cold months (October-March): OR = 1.05 (1.02, 1.09) for lags 0 and 2 and OR = 1.06 (1.02, 1.10) for lag 3. For female patients in the warm months (April-September): OR = 1.12 (1.06, 1.18) for lags 1 and 2. Cellulitis developing on uncovered (more exposed) skin was analyzed separately, observed effects being stronger. Cellulitis may be associated with exposure to ambient ground level ozone; the exposure may facilitate cellulitis infection and aggravate acute symptoms.

• Air pollution and emergency department visits for otitis media: a case-crossover study in Edmonton, Canada.

  Authors: Roger Zemek, Mieczysław Szyszkowicz, Brian H Rowe

  Environmental health perspectives. 11/2010; 118(11):1631-6.

  Otitis media (OM) is one of the most common early childhood infections, resulting in an enormous economic burden to the health care system through unscheduled doctor visits and antibioticOtitis media (OM) is one of the most common early childhood infections, resulting in an enormous economic burden to the health care system through unscheduled doctor visits and antibiotic prescriptions. The objective of this study was to investigate the potential association between ambient air pollution exposure and emergency department (ED) visits for OM. Ten years of ED data were obtained from Edmonton, Alberta, Canada, and linked to levels of air pollution: carbon monoxide (CO), nitrogen dioxide (NO2), ozone (O3), sulfur dioxide, and particulate matter (PM) of median aerometric diameter < or = 10 and 2.5 pm (PM10 and PM2.5 respectively). A time-stratified case-crossover technique was applied to analyze the associations between ambient air pollution and health outcomes. Conditional logistic regression analysis with the subject's identification number as a stratum variable was used to obtain odds ratios (ORs) and their corresponding 95% confidence intervals after adjustment for meteorological factors. We based the analysis on 14,527 ED visits for OM over 10 years in children 1-3 years of age. We observed statistically significant positive associations between ED visits for OM and interquartile increases in CO and NO2 levels after adjusting for ambient temperature and relative humidity. We observed the strongest associations (expressed by ORs) in the warmer months (April-September) in girls and all patients for exposure to CO and NO2, and in boys for exposure to CO, for 2 days before an OM ED visit. These results support the hypothesis that ED visits for OM are associated with ambient air pollution.

• Air pollution and emergency department visits for suicide attempts in vancouver, Canada.

  Authors: Mieczysław Szyszkowicz, Jeff B Willey, Eric Grafstein, Brian H Rowe, Ian Colman

  Environmental health insights. 01/2010; 4:79-86.

  Comorbidity of depression, heart disease, and migraine has been observed in clinical practice, while ambient air pollution has been identified among different risk factors for these healthComorbidity of depression, heart disease, and migraine has been observed in clinical practice, while ambient air pollution has been identified among different risk factors for these health conditions. Suicide attempts and ideations as the result of depression may be linked to air pollution exposure. Therefore the effects of ambient air pollution on emergency department (ED) visits for suicide attempts were investigated. Emergency visit data were collected in a hospital in Vancouver, Canada. The generalized linear mixed models technique was applied in the analysis of these data. A natural hierarchical structure of the data was used to define the clusters, with days nested in a 3-level structure (day of week, month, year). Poisson models were fitted to the clustered counts of ED visits with a single air pollutant, temperature and relative humidity. In addition, the case-crossover methodology was used with the same data for comparison. The analysis was performed by gender (all, males, females) and month (all: January-December, warm: April-September, cold: October-March). Both hierarchical and case-crossover methods confirmed positive and statistically significant associations among carbon monoxide (CO), nitrogen dioxide (NO(2)), sulphur dioxide (SO(2)), and particulate matter (PM(10)) for all suicide attempts in the cold period. The largest increase was observed for males in the cold period for a 1-day lagged exposure to NO(2), with an excess risk of 23.9% (95% CI: 7.8, 42.4) and odds ratio of 1.21 (95% CI: 1.03, 1.41). In warm months the associations were not statistically significant, and the highest positive value was obtained for ozone lagged by 1 day. The results indicate a potential association between air pollution and emergency department visits for suicide attempts.

• Air pollution and emergency department visits for chest pain and weakness in Edmonton, Canada.

  Authors: Mieczysław Szyszkowicz, Brian Rowe

  International journal of occupational medicine and environmental health. 01/2010; 23(1):15-9.

  Chest pain or weakness can be first signal of health problems. Many studies demonstrate that these conditions can be related to air pollution. This work uses time-series data to investigate theChest pain or weakness can be first signal of health problems. Many studies demonstrate that these conditions can be related to air pollution. This work uses time-series data to investigate the association. This is a study of 68,714 emergency department (ED) visits for chest pain (ICD-9: 786) and of 66,092 ED visits for weakness (ICD-9: 780). The hierarchical method was applied to analyse the associations between daily counts of ED visits for chest pain and weakness (separately) and the levels of the air pollutants and meteorological variables. The counts of visits for all patients, males and females were analysed separately by whole period (I-XII), warm (IV-IX) and cold (X-III). The results are presented in the form of the excess risks associated with an increase in the interquartile range (IQR) for the pollutant. Chest pain: 2.4% (95% CI: 1.0-3.9) for CO, females, I-XII; 3.8% (95% CI: 0.0-7.8) for NO(2), males, IV-IX; 4.5% (95% CI: 0.9-8.3) for O(3) (1-day lagged), males, IV-IX; 2.8% (95% CI: 0.5-5.2), for PM(10), males, X-III; 2.0% (95% CI: 0.0-4.0), for SO(2), females, X-III; 2.1% (95% CI: 0.2-4.0) for PM(2.5), all, X-III. Weakness: 2.1% (95% CI: 0.4-3.7) for CO (2-day lagged), males, X-III; 3.4% (95% CI: 1.0-5.9) for NO(2) (2-day lagged), males, X-III; 2.4% (95% CI: 0.9-3.9) for SO(2), females, I-XII; 4.6% (95% CI: 1.0-8.2) for O(3) (1-day lagged), females, IV-IX. Obtained findings provide support for the hypothesis that ED visits for chest pain and weakness are associated with exposure to ambient air pollution.

• Emergency department visits for migraine and headache: a multi-city study.

  Authors: Mieczysław Szyszkowicz, Gilaad Kaplan, Eric Grafstein, Brian Rowe

  International journal of occupational medicine and environmental health. 10/2009;

  Objectives: We set out to examine associations between ambient air pollution concentrations and emergency department (ED) visits for migraine/headache in a multi-city study. Materials and Methods: WeObjectives: We set out to examine associations between ambient air pollution concentrations and emergency department (ED) visits for migraine/headache in a multi-city study. Materials and Methods: We designed a time-series study of 64 839 ED visits for migraine (ICD-9: 346) and of 68 495 ED visits for headache (ICD-9: 784) recorded at hospitals in five different cities in Canada. The data (days) were clustered according to the hierarchical structure (location, year, month, day of week). The generalised linear mixed models technique was applied to fit the logarithm of clustered daily counts of ED visits for migraine, and separately for headache, on the levels of air pollutants, after adjusting for meteorological conditions. The analysis was performed by sex (all, male, female) and for three different seasonal periods: whole (January-December), warm (April-September), and cold (October-March). Results: For female ED visits for migraine, positive associations were observed during the warm season for sulphur dioxide (SO2), and in the cold season for particulate matter (PM2.5) exposures lagged by 2-days. The percentage increase in daily visits was 4.0% (95% CI: 0.8-7.3) for SO2 mean level change of 4.6 ppb, and 4.6% (95% CI: 1.2,-8.1) for PM2.5 mean level change of 8.3 mug/m3. For male ED visits for headache, the largest association was obtained during the warm season for nitrogen dioxide (NO2), which was 13.5% (95% CI: 6.7-20.7) for same day exposure. Conclusions: Our findings support the associations between air pollutants and the number of ED visits for headache.

• Ambient Air Pollution and Daily Emergency Department Visits for Ischemic Stroke in Edmonton, Canada.

  Authors: Mieczysław Szyszkowicz

  International journal of occupational medicine and environmental health. 02/2009;

  Objectives: In this report, we examine the associations between emergency department (ED) visits for acute ischemic stroke and environmental conditions. Materials and Methods: The study concerned 10Objectives: In this report, we examine the associations between emergency department (ED) visits for acute ischemic stroke and environmental conditions. Materials and Methods: The study concerned 10 881 ED visits for acute ischemic stroke (ICD-9: 434, 436) recorded at Edmonton hospitals between 1992 and 2002. Generalized linear mixed models technique was applied to build the statistical models. The logarithm of daily counts of ED visits for stroke was regressed on the levels of air pollutants (CO, NO2, SO2, and O3) and two meteorological variables. The analyses were performed by (a) age: two age groups were distinguished: 20-64 years (n = 2873) and 65-100 years (n = 8008); (b) season (all seasons: January-December, warm: April-September, cold: October-March); and (c) gender (both, male, female). Results: The results are reported as an excess risk in relation to an increase in the interquartile range (IQR) of the pollutants. In the age group 65-100 years, the excess risk for particular pollutants was as follows: for NO2-8.2% (95% CI: 0.4-16.7) for both genders, in the warm season; for SO2-9.1% (95% CI: 2.2-16.4), for males, in the warm season: for a 1-day lagged SO2-6.0% (95% CI: 0.5-11.8), for females, in the cold season. Among the patients aged 20-64 years, the excess risk for NO2 was 6.3% (95% CI: 0.2-12.8), for both genders, and all seasons; and 13.8% (95% CI: 2.1-26.7), for females, in the cold season; for a 1-day lagged O3-17.8% (95% CI: 2.2-35.6), for males, in the warm season; for a 1-day lagged SO2-10.3% (95% CI: 0.7-20.9) for females, in the cold season. Conclusions: The findings provide evidence that exposure to air pollutants is significantly associated with ED visits for acute ischemic stroke.

• Ambient air pollution and daily emergency department visits for asthma in Edmonton, Canada.

  Authors: Mieczysław Szyszkowicz

  International journal of occupational medicine and environmental health. 02/2008; 21(1):25-30.

  OBJECTIVES: As demonstrated by many studies, emergency department (ED) visits for asthma can be associated with air pollution exposures. The aim of this study was to examine and assess the potentialOBJECTIVES: As demonstrated by many studies, emergency department (ED) visits for asthma can be associated with air pollution exposures. The aim of this study was to examine and assess the potential relations between ED visits for asthma and the concentrations of ambient air pollutants. MATERIALS AND METHODS: Generalized linear mixed model was applied to study 62,563 ED visits for asthma (ICD-9: 493) in Edmonton, Canada. Two age groups, with 10 years of age as a separator, were considered by gender and season of the year: all (I-XII), warm (IV-IX) and cold (X-III). RESULTS: The percentage increase in daily ED visits for asthma was 17.8% (95% CI: 7.1-29.5) and 13.8% (95% CI: 3.3-25.3) for females below 10 years of age, in the period of IV-IX, for current day and 1-day lagged exposure to ozone (O(3)), respectively. The percentage increase was 19.2% (95% CI: 11.4-27.6) for males below 10 years of age, in the period of IV-IX, for 2-day lagged exposure to nitrogen dioxide (NO(2)). CONCLUSIONS: The findings provide support for the hypothesis that ED visits for asthma are associated with exposure to O(3). This study underlines the significant role of air pollutants as triggering asthma attacks.

• Air pollution and emergency department visits for depression in Edmonton, Canada.

  Authors: Mieczysław Szyszkowicz

  International journal of occupational medicine and environmental health. 02/2007; 20(3):241-5.

  OBJECTIVE: Depression is a common cause of morbidity. Sufferers are very sensitive to many external factors. Emergency department (ED) visits for this condition can be associated with theOBJECTIVE: Depression is a common cause of morbidity. Sufferers are very sensitive to many external factors. Emergency department (ED) visits for this condition can be associated with the concentration of ambient air pollutants. The study objective was to examine and assess the associations between ED visits for depression and ambient air pollution. DESIGN AND METHODS: The present study analyzed 15,556 ED visits for depression (ICD-9: 311) at Edmonton hospitals between 1992 and 2002. The data were clustered based on the triplet {year, month, day of the week}. The generalized linear mixed models (GLMM) technique was used to regress the logarithm of the clustered counts for ED visits for depression on the levels of air pollutants (CO, NO2, SO2, O3, PM10 and PM2.5) and the meteorological variables. The number of ED visits for depression was analyzed separately for all patients, and males and females. An analysis by season was also conducted: for the whole year (I-XII), warm season (IV-IX), and cold season (X-III). RESULTS: After adjusting for temperature and relative humidity, the following increments in daily depression-related ED visits could be noted: 6.9% (95% CI: 1.3, 12.9) for carbon monoxide (CO) for all patients in warm season; 7.4% (95% CI: 0.5, 14.8) for nitrogen dioxide (NO2) for female patients in warm season; 4.5% (95% CI: 0.1, 9.1) for sulphur dioxide (SO2) for female patients in warm season; 6.9% (95% CI: 0.6, 13.6) for ground level ozone (O3, 1-day lagged) for female patients in warm season; 7.2% (95% CI: 2.7, 12.0) for particulate matter (PM10) for females in cold season; and 7.2% (95% CI: 2.0, 12.8) for particulate matter (PM2.5) for females in cold season. CONCLUSIONS: The findings provide support for the hypothesis that ED visits for depression are associated with exposure to ambient air pollution.

• Air pollution and emergency department visits for ischemic heart disease in Montreal, Canada.

  Authors: Mieczysław Szyszkowicz

  International journal of occupational medicine and environmental health. 02/2007; 20(2):167-73.

  OBJECTIVES: We examined the associations between emergency department (ED) visits for ischemic heart disease (IHD) and short-term elevations in ambient air pollutants (CO and NO(2)). MATERIALS ANDOBJECTIVES: We examined the associations between emergency department (ED) visits for ischemic heart disease (IHD) and short-term elevations in ambient air pollutants (CO and NO(2)). MATERIALS AND METHODS: A hierarchical clusters design was used to study ED visits (n = 4979) for ischemic heart disease (ICD-9: 410-414) that occurred at a Montreal hospital between 1997 and 2002. The generalized linear mixed models technique was applied to create Poisson models for the clustered counts of ED visits for IHD. The analysis was done by gender for two age categories, all patients and patients aged over 64 years. RESULTS: The results are presented as an excess risk increase associated with the interquartile range (IQR) of daily average of the pollutant concentration. The results for NO(2) (IQR = 9.5 ppb) were 5.9% (95% CI: 2.1-9.9) for all patients and 6.2% (95% CI: 1.2-11.4) for males; for patients aged over 64: 7.1% (95% CI: 2.5-11.9) for all patients, 9.1% (95% CI: 2.8-15.7) for males, and 6.5% (95% CI: 0.7-12.7) for females (for exposure lagged by 1-day). The results for CO (IQR = 0.2 ppm): 5.4% (95% CI: 2.3-8.5) for all patients, and 7.5% (95% CI: 3.6-11.6) for males. For patients aged over 64 years, 4.9% (95% CI: 1.3-8.7) for all patients, and 7.5% (95% CI: 2.6-12.6) for males. The results show the associations for the same day exposures. CONCLUSIONS: The short-term effects of nitrogen dioxide and carbon monoxide are associated significantly with daily ED visits for ischemic heart disease. For NO(2) the associations are stronger for patients aged over 64 years. As indicated by our results, it is likely that vehicular traffic, a producer of NO(2) and CO, contributes to an increased number of ED visits for IHD.

• Use of generalized linear mixed models to examine the association between air pollution and health outcomes.

  Authors: Mieczysław Szyszkowicz

  International journal of occupational medicine and environmental health. 01/2006; 19(4):224-7.

  Time-series and case-crossover are two techniques that are widely used for assessing the short-term impact of ambient air pollution exposure on health. The generalized linear mixed model (GLMM)Time-series and case-crossover are two techniques that are widely used for assessing the short-term impact of ambient air pollution exposure on health. The generalized linear mixed model (GLMM) methodology is proposed here to study the association between ambient air pollution and health outcomes. Poisson random-effects models are applied to analyze the clustered counts, where the groups of days, determined by the triplet <day of week, month, year>, form the clusters. The proposed technique uses a nested structure for the clusters and allows random-effects for hierarchical factors. A random intercept in the models adjusts for different levels of counts among the clusters. A fixed slope represents a common response to the exposure. The obtained results are consistent with those generated by a classical approach (for example the case-crossover technique). The GLMM technique is a valid alternative methodology for studying air health effects.