Cold Weather Conditions and Risk of Hypothermia Among People Experiencing Homelessness: Implications for Prevention Strategies.

Hypothermia is a preventable condition that disproportionately affects individuals who experience homelessness, yet limited data exist to inform the response to cold weather. To fill this gap, we examined the association between meteorological conditions and the risk of hypothermia among homeless individuals. Hypothermic events were identified from emergency department charts and coroner's records between 2004 and 2015 in Toronto, Canada. A time-stratified case-crossover design with conditional logistic regression was used to assess the relationship between the meteorological conditions (minimum temperature and precipitation) and the risk of hypothermia. There were 97 hypothermic events identified: 79 injuries and 18 deaths. The odds of experiencing a hypothermic event increased 1.64-fold (95% CI: 1.30-2.07) with every 5 °C decrease in the minimum daily temperature and 1.10-fold (95% CI: 1.03-1.17) with every 1 mm increase in precipitation. The risk of hypothermia among individuals experiencing homelessness increased with declining temperature; however, most cases occurred during periods of low and moderate cold stress. 72% occurred when the minimum daily temperatures were warmer than -15 °C. These findings highlight the importance of providing a seasonal cold weather response to prevent hypothermia, complemented by an alert-based response on extremely cold days.

Late preterm birth and previous cesarean section: a population-based cohort study.

BACKGROUND: Late preterm birth (LPB) is increasingly common and associated with higher morbidity and mortality than term birth. Yet, little is known about the influence of previous cesarean section (PCS) and the occurrence of LPB in subsequent pregnancies. We aim to evaluate this association along with the potential mediation by cesarean sections in the current pregnancy. METHODS: We use population-based birth registry data (2005-2012) to establish a cohort of live born singleton infants born between 34 and 41 gestational weeks to multiparous mothers. PCS was the primary exposure, LPB (34-36 weeks) was the primary outcome, and an unplanned or emergency cesarean section in the current pregnancy was the potential mediator. Associations were quantified using propensity weighted multivariable Poisson regression, and mediating associations were explored using the Baron-Kenny approach. RESULTS: The cohort included 481,531 births, 21,893 (4.5%) were LPB, and 119,983 (24.9%) were predated by at least one PCS. Among mothers with at least one PCS, 6307 (5.26%) were LPB. There was increased risk of LPB among women with at least one PCS (adjusted Relative Risk (aRR): 1.20 (95%CI [1.16, 1.23]). Unplanned or emergency cesarean section in the current pregnancy was identified as a strong mediator to this relationship (mediation ratio = 97%). CONCLUSIONS: PCS was associated with higher risk of LPB in subsequent pregnancies. This may be due to an increased risk of subsequent unplanned or emergency preterm cesarean sections. Efforts to minimize index cesarean sections may reduce the risk of LPB in subsequent pregnancies.

A Census of Midsize to Large Supermarkets in Toronto: A Cross-Sectional Analysis of the Consumer Nutrition Environment.

OBJECTIVE: Assess the consumer nutrition environment in midsize to large supermarkets by supermarket type and area-level socioeconomic variables. DESIGN: Cross-sectional census of 257 supermarkets using the Toronto Nutrition Environment Measures Survey in Stores. SETTING: Toronto, Canada. VARIABLES MEASURED: Availability; price and linear shelf space of fruits and vegetables vs energy-dense snack foods by supermarket type; after-tax, low-income measure; and neighborhood improvement area. ANALYSIS: Multivariate linear regression. RESULTS: There was a high availability of fruits (7.7 of 8) and vegetables (9.5 of 11). There was similar linear shelf space for fruits and vegetables vs energy-dense snack foods (ratio, 1.1 m). Adjusted fruit prices were lowest in quintiles 1 (ß = -$1.30; P = .008), 2 (ß = -$1.41; P = .005), and 3 (ß = -$1.89; P < .001) vs quintile 5 (lowest percentage of people living with low income) and in ethnic (ß = -$3.47; P < .001) and discount stores (ß = -$5.64; P < .001) vs conventional. Adjusted vegetable prices were lowest in quintiles 2 (ß = -$1.87; P = .04), 3 (ß = -$1.78; P = .03), and 4 (ß = -$2.65; P = .001) vs quintile 5 and in ethnic (ß = -$7.10; P < .001) and discount (ß = -$5.49; P < .001) stores. They were highest in other (ß = + $3.08; P = .003) vs conventional stores. Adjusted soda and chips prices were lower in discount (ß = -$1.16; P < .001) and higher in other stores (ß = + $0.67; P < .001) vs conventional. CONCLUSIONS AND IMPLICATIONS: Findings do not indicate inequities in shelf space, availability, or price across diverse neighborhoods. Practitioners can use findings to help consumers navigate supermarkets to make healthy choices.

Severe Neonatal Morbidity Among Births to Refugee Women.

Background Despite being considered high risk, little is known about the perinatal health of refugees in developed countries. Our objectives were to examine whether: (1) the healthy migrant effect applies to infants born to refugee women with respect to severe neonatal morbidity (SNM); (2) refugee status was a risk factor for SNM among immigrants; (3) refugee sponsorship status was a risk factor for SNM by comparing asylum-seekers to sponsored refugees; and (4) refugees were at greater risk of specific SNM subtypes. Methods Immigration records (1985-2010) linked to Ontario hospital data (2002-2010) were used to examine SNM. We calculated adjusted risk ratios (ARR) with 95 % confidence intervals (95 % CI) for SNM and unadjusted risk ratios with 99 % CI for SNM subtypes using log-binomial regression. Results There were borderline differences in SNM among refugees (N = 29,755) compared to both non-immigrants (N = 860,314) (ARR = 0.94, 95 % CI 0.89, 0.99) and other immigrants (N = 230,847) (ARR = 1.10, 95 % CI 1.04, 1.18) with a larger difference comparing other immigrants to non-immigrants (ARR = 0.83, 95 % CI 0.81, 0.85). Asylum-seekers did not differ from sponsored refugees (ARR = 1.07, 95 % CI 0.90, 1.27). Though rare, several SNM subtypes were significant with large effect sizes. Conclusion With respect to SNM risk, the healthy migrant effect clearly applies to non-refugee immigrants, but is weaker for refugees and may not apply. Among immigrants, refugee status was a weak risk factor for SNM and may not be clinically important. Sponsorship status was not associated with greater risk of SNM. Further investigation of several SNM subtypes is warranted.

Spatial variability of gastroschisis in Canada, 2006-2011: An exploratory analysis.

OBJECTIVES: Gastroschisis is a serious birth defect of the abdominal wall that is associated with mortality and significant morbidity. Our understanding of the factors causing this defect is limited. The objective of this paper is to describe the geographic variation in incidence of gastroschisis and characterize the spatial pattern of all gastroschisis cases in Canada between 2006 and 2011. Specifically, we aimed to ascertain the differences in spatial patterns between geographic regions and identify significant clusters and their location. METHODS: The study population included 641 gastroschisis cases from the Canadian Pediatric Surgery Network (CAPSNet) database, a population-based dataset of all gastroschisis cases in Canada. Cases were geocoded based on maternal residence. Using Statistics Canada live-birth data as a denominator, the total prevalence of gastroschisis was calculated at the provincial/territorial levels. Random effects logistic models were used to estimate the rates of gastroschisis in each census division. These rates were then mapped using ArcGIS. Cluster detection was performed using Local Indicators of Spatial Association (LISA). RESULTS: There is significant spatial heterogeneity of the rate of gastroschisis across Canada at both the provincial/territorial and census-division level. The Yukon, Northwest Territories and Prince Edward Island have higher overall rates of gastroschisis relative to other provinces/territories. Several census divisions in Alberta, Manitoba, Saskatchewan, Ontario, Northwest Territories and British Columbia demonstrated case "clusters", i.e., focally higher rates in discrete areas relative to surrounding areas. CONCLUSIONS: There is clear evidence of spatial variation in the rates of gastroschisis across Canada. Future research should explore the role of area-based variables in these patterns to improve our understanding of the etiology of gastroschisis.

The influence of refugee status and secondary migration on preterm birth.

BACKGROUND: It is unknown whether the risk of preterm birth (PTB) is elevated for forced (refugee) international migrants and whether prolonged displacement amplifies risk. While voluntary migrants who arrive from a country other than their country of birth (ie, secondary migrants) have favourable birth outcomes compared with those who migrated directly from their country of birth (ie, primary migrants), secondary migration may be detrimental for refugees who experience distinct challenges in transition countries. Our objectives were (1) to determine whether refugee status was associated with PTB and (2) whether the relation between refugee status and PTB differed between secondary and primary migrants. METHODS: We conducted a retrospective population-based cohort study. Ontario immigration (2002-2010) and hospitalisation data (2002-2010) were linked to estimate adjusted cumulative odds ratios (ACOR) of PTB (22-31, 32-36, 37-41 weeks of gestation), with 95% CIs (95% CI) comparing refugees with non-refugees. We further included a product term between refugee status and secondary migration. RESULTS: Overall, refugees (N=12 913) had 17% greater cumulative odds of short gestation (ACOR=1.17, 95% CI 1.07 to 1.28) compared with non-refugees (N=110 640). Secondary migration modified the association between refugee status and PTB (p=0.007). Secondary refugees had 58% greater cumulative odds of short gestation (ACOR=1.58, 95% CI 1.25 to 2.00) than secondary non-refugees, while primary refugees had 12% greater cumulative odds of short gestation (ACOR=1.12, 95% CI 1.02 to 1.23) than primary non-refugee immigrants. CONCLUSIONS: Refugee status, jointly with secondary migration, influences PTB among migrants.

Contribution of HIV to Maternal Morbidity Among Refugee Women in Canada.

OBJECTIVES: We compared severe maternal morbidity (SMM) and SMM subtypes, including HIV, of refugee women with those of nonrefugee immigrant and nonimmigrant women. METHODS: We linked 1,154,421 Ontario hospital deliveries (2002-2011) to immigration records (1985-2010) to determine the incidence of an SMM composite indicator and its subtypes. We determined SMM incidence according to immigration periods, which were characterized by lifting restrictions for all HIV-positive immigrants (in 1991) and refugees who may place "excessive demand" on government services (in 2002). RESULTS: Refugees had a higher risk of SMM (17.1 per 1000 deliveries) than did immigrants (12.1 per 1000) and nonimmigrants (12.4 per 1000). Among SMM subtypes, refugees had a much higher risk of HIV than did immigrants (risk ratio [RR] = 7.94; 95% confidence interval [CI] = 5.64, 11.18) and nonimmigrants (RR = 17.37; 95% CI = 12.83, 23.53). SMM disparities were greatest after the 2002 policy came into effect. After exclusion of HIV cases, SMM disparities disappeared. CONCLUSIONS: An apparent higher risk of SMM among refugee women in Ontario, Canada is explained by their high prevalence of HIV, which increased over time parallel to admission policy changes favoring humanitarian protection.

Integrating environmental and human health databases in the great lakes basin: themes, challenges and future directions.

Many government, academic and research institutions collect environmental data that are relevant to understanding the relationship between environmental exposures and human health. Integrating these data with health outcome data presents new challenges that are important to consider to improve our effective use of environmental health information. Our objective was to identify the common themes related to the integration of environmental and health data, and suggest ways to address the challenges and make progress toward more effective use of data already collected, to further our understanding of environmental health associations in the Great Lakes region. Environmental and human health databases were identified and reviewed using literature searches and a series of one-on-one and group expert consultations. Databases identified were predominantly environmental stressors databases, with fewer found for health outcomes and human exposure. Nine themes or factors that impact integration were identified: data availability, accessibility, harmonization, stakeholder collaboration, policy and strategic alignment, resource adequacy, environmental health indicators, and data exchange networks. The use and cost effectiveness of data currently collected could be improved by strategic changes to data collection and access systems to provide better opportunities to identify and study environmental exposures that may impact human health.

Maternal risk factors for gastroschisis in Canada.

BACKGROUND: Gastroschisis is a congenital abdominal wall defect that occurs in one per 2200 pregnancies. Birth defect surveillance in Canada has shown that the prevalence of gastroschisis has increased threefold over the past 10 years. The purpose of this study was to compare maternal exposures data from a national gastroschisis registry with pregnancy exposures from vital statistics to understand maternal risk factor associations with the occurrence of gastroschisis. METHODS: Using common definitions, pregnancy cohorts were developed from two databases. The Canadian Pediatric Surgery Network database, a population-based dataset was used to record maternal exposures for women who experienced a gastroschisis pregnancy, while a contemporaneous, geographically cross-sectional "control" cohort of pregnant women and their exposures was developed from Canadian Community Health Survey data. Groups comparison of maternal risk factors was performed using univariate and multivariate logistic generalized estimating equation techniques. RESULTS: A total of 692 gastroschisis pregnancies (from Canadian Pediatric Surgery Network) and 4708 pregnancies from Canadian Community Health Survey were compared. Younger maternal age (odds ratio, 0.85; 95% confidence interval, 0.83-0.87; p < 0.0001), smoking (odds ratio, 2.86; 95% confidence interval, 2.22-3.66; p < 0.0001), a history of pregestational or gestational diabetes (odds ratio, 2.81; 95% confidence interval, 1.42-5.5; p = 0.0031), and use of medication to treat depression (odds ratio, 4.4; 95% confidence interval, 1.38-11.8; p = 0.011) emerged as significant associations with gastroschisis pregnancies. CONCLUSION: Gastroschisis in Canada is associated with maternal risk factors, some of which are modifiable. Further studies into sociodemographic birth defect risk are necessary to allow targeted improvements in perinatal health service delivery and health policy.

The association between obstetrical interventions and late preterm birth.

OBJECTIVE: There is concern that obstetric interventions (prelabor cesarean section and induced delivery) are drivers of late preterm (LP) birth. Our objective was to evaluate the independent association between obstetric interventions and LP birth and explore associated independent maternal and fetal risk factors for LP birth. STUDY DESIGN: In this population-based cross-sectional study, the BORN Information System was used to identify all infants born between 34 and 40 completed weeks of gestation between 2005 and 2012 in Ontario, Canada. The association between obstetric interventions (preterm cesarean section and induced delivery) and LP birth (34 to 36 completed weeks' gestation vs 37 to 40 completed weeks' gestation) was assessed using generalized estimating equation regression. RESULTS: Of 917,013 births between 34 and 40 weeks, 49,157 were LP (5.4%). In the adjusted analysis, "any obstetric intervention" (risk ratio [RR], 0.65; 95% confidence interval [CI], 0.57-0.74), induction (RR, 0.71; 95% CI, 0.61-0.82) and prelabor cesarean section (RR, 0.66; 95% CI, 0.59-0.74) were all associated with a lower likelihood of LP vs term birth. Several independent potentially modifiable risk factors for LP birth were identified including previous cesarean section (RR, 1.28; 95% CI, 1.16-1.40), smoking during pregnancy (RR, 1.28; 95% CI, 1.21-1.36) and high material (RR, 1.1; 95% CI, 1.03-1.18) and social (RR, 1.09; 95% CI, 1.02-1.16) deprivation indices. CONCLUSION: After accounting for differences in maternal and fetal risk, LP births had a 35% lower likelihood of obstetric interventions than term births. Obstetric care providers may be preferentially avoiding induction and prelabor cesarean section between 34 and 37 weeks' gestation.

Impact of late preterm and early term infants on Canadian neonatal intensive care units.

OBJECTIVE: To examine the short-term morbidities, mortality, and use of neonatal intensive care unit (NICU) resources for late preterm, early term, and term infants. STUDY DESIGN: Infants born between 34 and 40 weeks of gestation and admitted to a Canadian NICU in 2010 were designated late preterm (340/7 to 366/7 weeks), early term (370/7 to 386/7 weeks), or term (390/7 to 406/7 weeks). Mortality, short-term morbidities, and resource utilization were compared between the three groups using chi-square tests and analysis of variance. RESULTS: Among 6,636 included infants, 44.2% (n = 2,935) were late preterm, 26.2% (n = 1,737) early term, and 29.6% (n = 1,964) term. Term infants were more likely to require resuscitation at birth and had lower Apgar scores than late preterm and early term infants (p < 0.001). Length of stay and need for respiratory support decreased with increasing gestational age; however, the proportion of hospital days that intensive care was required increased. CONCLUSION: The greatest impact of late preterm infants is on NICU bed occupancy, whereas for term infants it is on intensity of care. Early term infants experience greater rates of some complications than term, demonstrating that risk persists for these infants. These findings have important implications for NICU resource planning and practice.

Prediction of neonatal outcomes in extremely preterm neonates.

OBJECTIVE: To develop and validate a statistical prediction model spanning the severity range of neonatal outcomes in infants born at ≤ 30 weeks' gestation. METHODS: A national cohort of infants, born at 23 to 30 weeks' gestation and admitted to level III NICUs in Canada in 2010-2011, was identified from the Canadian Neonatal Network database. A multinomial logistic regression model was developed to predict survival without morbidities, mild morbidities, severe morbidities, or mortality, using maternal, obstetric, and infant characteristics available within the first day of NICU admission. Discrimination and calibration were assessed using a concordance C-statistic and the Cg goodness-of-fit test, respectively. Internal validation was performed using a bootstrap approach. RESULTS: Of 6106 eligible infants, 2280 (37%) survived without morbidities, 1964 (32%) and 1251 (21%) survived with mild and severe morbidities, respectively, and 611 (10%) died. Predictors in the model were gestational age, small (<10th percentile) for gestational age, gender, Score for Neonatal Acute Physiology version II >20, outborn status, use of antenatal corticosteroids, and receipt of surfactant and mechanical ventilation on the first day of admission. High model discrimination was confirmed by internal bootstrap validation (bias-corrected C-statistic = 0.899, 95% confidence interval = 0.894-0.903). Predicted probabilities were consistent with the observed outcomes (Cg P value = .96). CONCLUSIONS: Neonatal outcomes ranging from mortality to survival without morbidity in extremely preterm infants can be predicted on their first day in the NICU by using a multinomial model with good discrimination and calibration. The prediction model requires additional external validation.

Relationship of mode of conception and sex concordance with mortality/morbidity in preterm twins.

OBJECTIVE: To assess the association of mode of conception and sex concordance with neonatal outcomes in very preterm twins. STUDY DESIGN: Twin pairs born at gestational age ≤ 32 weeks and admitted to a Level 3 neonatal intensive care unit (NICU) in 2010-2011 were retrospectively identified from the Canadian Neonatal Network™ database. A composite outcome representing neonatal mortality or any severe morbidity (intraventricular hemorrhage grades ≥ 3 or periventricular leukomalacia, retinopathy of prematurity stages ≥ 3, bronchopulmonary dysplasia, or necrotizing enterocolitis stages ≥ 2) was compared between twins conceived using assisted reproduction technologies (ARTs) or spontaneously (SP), and tested for association with sex concordance in individual-level and pair-wise multivariable logistic regression analyses. RESULTS: Study subjects included 1,508 twins from 216 ART (53 [25%] male-male, 104 [48%] male-female, and 59 [27%] female-female) and 538 SP (192 [36%] male-male, 123 [23%] male-female, and 223 [41%] female-female) pairs. No statistically significant association was detected between mode of conception and the composite outcome of mortality/morbidities. The composite outcome was significantly higher in same-sex than in opposite-sex twins (OR = 1.68; 95% CI = [1.09, 2.59]). This relationship was most pronounced in ART pairs (OR = 2.25; 95% CI = [1.02, 4.98]), with increased rates in one or both twins from male-male versus opposite-sex ART pairs (OR = 3.0; 95% CI = [1.07, 8.36]). CONCLUSION: Same-sex pairing was associated with higher mortality/morbidities in very preterm twins admitted to the NICU, and can be used in clinical practice to identify twins at higher risk of adverse neonatal outcomes.

Seasonal variations in healthcare-associated infection in neonates in Canada.

OBJECTIVE: To assess the seasonal pattern of healthcare-associated infections (HCAI) among neonates and to describe the trend of HCAI. DESIGN: Secondary analyses of database. SETTING: The Canadian Neonatal Network database (2003-2009). PARTICIPANTS: Neonates with HCAI defined as blood/cerebrospinal fluid positive with pathogenic organism in a symptomatic infant after 2 days of age. MAIN OUTCOME MEASURE: The incidence rate for HCAI per 1000 days with a 95% CI, for the 4 warmest months (June-September) was compared with the remaining 8 months, to calculate the incidence rate ratio (IRR). RESULTS: Of 75 629 total infants, 4305 (5.7%) had HCAI (3367 had 1 and 938 had >1 episodes). Infants who had HCAI were of lower gestation, birth weight and Apgar score; but had higher severity of illness scores and clinical chorioamnionitis. There was a borderline increase in all HCAI (IRR 1.05, 95% CI 1.00 to 1.11) and a significant increase in Gram-negative HCAI (IRR 1.20, 95% CI 1.04 to 1.39) during the summer months. Overall, there was a 20% reduction in HCAI from 4.45/1000 days in January 2003 to 3.54/1000 days in December 2009 (mean difference 0.91/1000 days (95% CI 0.89 to 0.92). CONCLUSIONS: Gram-negative infections were significantly increased during the summer months of the year compared with the rest of the year among neonates. Overall, there was a significant temporal reduction in HCAI rates over the study period.

Association between congenital anomalies and area-level deprivation among infants in neonatal intensive care units.

OBJECTIVE: To examine the relationship between area-level material deprivation and the risk of congenital anomalies in infants admitted to neonatal intensive care units (NICUs) across Canada. STUDY DESIGN: The Canadian Neonatal Network database was used to identify admitted infants who had congenital anomalies between 2005 and 2009. The association between congenital anomalies and material deprivation quintile was assessed using logistic regression analysis. RESULTS: Of 55,961 infants admitted to participating NICUs during the study period, 6002 (10.7%) had major, 6244 (11.2%) had minor, and 43,715 (78.1%) had no anomalies. There were higher odds of major anomalies (odds ratio [OR] 1.13, 95% confidence interval [CI] 1.03 to 1.24) but not minor anomalies (OR 1.01, 95% CI 0.93 to 1.11) in the highest-deprivation areas as compared with the lowest-deprivation area of maternal residence. Analyses of groups of major anomalies revealed higher odds for chromosomal (OR 1.48, 95% CI 1.05 to 2.10) and multiple-systems (OR 1.40, 95% CI 1.14 to 1.71) anomalies in the highest-deprivation areas compared with the lowest-deprivation areas. CONCLUSION: There are socioeconomic inequalities in the risk of major congenital anomalies, especially chromosomal and multiple-systems anomalies, in the NICU population with the highest rates in the most socioeconomically deprived areas.

The changing epidemiology of preterm twins and triplets admitted to neonatal intensive care units in Canada, 2003 to 2008.

We describe trends in the rates of admission of preterm twin and triplet infants to neonatal intensive care units (NICUs) across Canada and compare their neonatal outcomes over a 6-year period. Temporal trends of admission rates for 5193 twins and triplets < 33 weeks' gestational age to participating NICUs in the Canadian Neonatal Network between 2003 and 2008 were assessed. Trends in infant outcomes were evaluated using logistic regression. The proportion of twins increased from 26.1 to 28.0 per 100 admissions between 2003 and 2008 (7% increase, p = 0.02). In contrast, the proportion of triplets decreased from 5.0 to 3.3 per 100 admissions (34% reduction, p = 0.04). These trends were significant in mothers ≥ 35 years of age. Neonatal outcomes improved for preterm twins (mortality, p < 0.01; survival without any major morbidity, p < 0.01; severe neurological injury, p = 0.02; and severe retinopathy of prematurity, p = 0.03). Similar improvements were observed for triplets, but the sample size was insufficient to reach statistical significance. The rate of NICU admissions for preterm twins at < 33 weeks' gestation has increased in recent years, whereas for triplets it has gradually declined. Neonatal outcomes of preterm twins improved over the study period.

The relationship between temperature and ambulance response calls for heat-related illness in Toronto, Ontario, 2005.

BACKGROUND: Concern over the adverse effects of heat on human health has led to numerous studies assessing the relationship between heat and mortality. Few studies have quantified the impact of heat on morbidity, including ambulance response calls. This study describes the association between temperature and ambulance response calls for heat-related illness (HRI) in Toronto, Ontario, Canada during the summer of 2005. METHODS: Data sources included daily temperature, relative humidity and humidex information from Environment Canada, and Medical Priority Dispatch System data from Toronto Emergency Medical Services. Time series and regression analyses were used to examine the relationship between daily temperature and ambulance response calls for HRI during the summer (1 June to 31 August) of 2005. RESULTS: In 2005, there were 201 ambulance response calls for HRI. On average, for every one degree increase in maximum temperature (°C) there was a 29% increase in ambulance response calls for HRI (p<0.0001). For every one degree increase in mean temperature (°C) there was a 32% increase in ambulance response calls for HRI (p<0.0001). CONCLUSIONS: Given these associations, we urge further exploration of ambulance response calls as a source of HRI morbidity data particularly given the increasing health concerns associated with climate change.

Effectiveness of public health interventions in reducing morbidity and mortality during heat episodes: a structured review.

Increasing concern over the impact of hot weather on health has fostered the development of public health interventions to reduce heat-related health impacts. However, evidence of the effectiveness of such interventions is rarely cited for justification. Our objective was to review peer-reviewed and grey literature evaluating interventions aimed at reducing morbidity and/or mortality in populations during hot weather episodes. Among studies considering public risk perceptions, most respondents were aware when an extreme heat episode was occurring but did not necessarily change their practices, primarily due to a lack of self-perception as vulnerable and confusion about the appropriate actions to be taken. Among studies of health outcomes during and following heat episodes, studies were suggestive of positive impacts in reducing morbidity and mortality. While the limited evaluative work to date suggests a positive impact of public health interventions, concern persists about whether the most vulnerable groups, like the elderly and homeless, are being adequately reached.

Climate change and health in british columbia: projected impacts and a proposed agenda for adaptation research and policy.

This is a case study describing how climate change may affect the health of British Columbians and to suggest a way forward to promote health and policy research, and adaptation to these changes. After reviewing the limited evidence of the impacts of climate change on human health we have developed five principles to guide the development of research and policy to better predict future impacts of climate change on health and to enhance adaptation to these change in BC. We suggest that, with some modification, these principles will be useful to policy makers in other jurisdictions.

Temporal and spatial variation of heat-related illness using 911 medical dispatch data.

BACKGROUND: The adverse effect of hot weather on health in urban communities is of increasing public health concern, particularly given trends in climate change. OBJECTIVES: To demonstrate the potential public health applications of monitoring 911 medical dispatch data for heat-related illness (HRI), using historical data for the summer periods (June 1-August 31) during 2002-2005 in Toronto, Ontario, Canada. METHODS: The temporal distribution of the medical dispatch calls was described in relation to a current early warning system and emergency department data from the National Ambulatory Care Reporting System (NACRS). Geospatial methods were used to map the percentage of heat-related calls in each Toronto neighborhood over the study period. RESULTS: The temporal pattern of 911 calls for HRI was similar, and sometimes peaked earlier, than current heat health warning systems (HHWS). The pattern of calls was similar to NACRS HRI visits, with the exception of 2005 where 911 calls peaked earlier. Areas of the city with a relatively higher burden of HRI included low income inner-city neighborhoods, areas with high rates of street-involved individuals, and areas along the waterfront which include summer outdoor recreational activities. CONCLUSIONS: Identifying the temporal trends and geospatial patterns of these important environmental health events has the potential to direct targeted public health interventions to mitigate associated morbidity and mortality.