Biomedical subjects

Clyde Hertzman

Publications and source records attributed to Clyde Hertzman.

At least 19 recordsLinked to original sources

PubMed2007

Impact of the specificity of the exposure metric on exposure-response relationships.

BACKGROUND: Exposure misclassification may occur when nonspecific exposure indicators are used. Developing estimates of more specific measures may be difficult due to sampling limitations or a paucity of historical measurements and, thus, often requires substantial effort. We examine the impact on exposure-response relationships of moving from 2 measures of exposure mixtures (dust, chlorophenols) to more specific exposure indicators (wood dust, pentachlorophenol, tetrachlorophenol) in a retrospective cohort. METHODS: The study population consisted of 26,847 male sawmill workers (> or =1 year employment between 1950 and 1995) with linkage to national cancer registries. A subcohort (n = 11,273 employed more than 1 day between 1985 and 1995) was linked to hospital discharge records. We evaluated the shape (log-linear vs log-log models), goodness of fit, precision, and expected versus observed attenuation of the exposure-response relationships. RESULTS: The correlation between the cumulative exposure indices was moderately high (dust/wood dust, r = 0.68; total chlorophenol/pentachlorophenol, r = 0.88; total chlorophenol/tetrachlorophenol, r = 0.78). An increase in chronic obstructive pulmonary disease hospitalizations was found with wood dust but not with total dust. Stronger associations for non-Hodgkin lymphoma and kidney cancer incidence were observed with pentachlorophenol than with total chlorophenol; no association was observed with tetrachlorophenol. We observed greater attenuation than expected using total dust, but less than expected using total chlorophenol. CONCLUSIONS: The relationships between health outcomes were substantially attenuated when nonspecific exposure indicators were used. This study demonstrates the importance of developing exposure metrics as specific to the disease-causing agent as possible, particularly when the composition of mixed exposures varies by work areas.

British Columbia↗

PubMed2006

Towards an epidemiological understanding of the effects of long-term institutional changes on population health: a case study of Canada versus the USA.

This paper uses a comparative case study of Canada and the USA to argue that, in order to fully understand the associations between population health and the socioeconomic environment we must begin to place importance on the dynamic aspect of these factors--examining them as they evolve over time. In particular, for institutional and policy shifts that often unfold over decades, population health must attend to these big, slow moving processes by adopting a historical perspective to the knowledge base. We compare Canada and the USA on basic health outcomes and a range of determinants of health for which routine data have been collected for all or most of the period between 1950 and the present. During the analysis that follows, we are able to establish that, at the level of society (i) greater economic well being and spending on health care does not yield better health outcomes, that (ii) public provision and income redistribution trump economic success where population health is concerned, and (iii) that the gradual development of public provision represents the buildup of social infrastructure that has long-lasting effects on health status. Our case study shows what can be gleaned from a comparative perspective and a long-term view. The long view allows us to detect the gradual divergence in health status between these two societies and to trace potential institutional causes that would otherwise go unnoticed. The perspective introduced here, and in particular the comparison of Canada and the USA, provides strong support for the use of cross-national comparative work, and a historical perspective on the investigation of societies that successfully support population health.

Canada↗

PubMed2006

Associations of early growth and adult adiposity with patterns of salivary cortisol in adulthood.

CONTEXT: Early growth and obesity are associated with adult chronic disease. A suspected mediator is the hypothalamic-pituitary-adrenal axis and cortisol regulation. Our prior hypothesis was that cortisol levels are affected by anthropometry at several life stages. OBJECTIVE: The objective of the study was to assess whether prenatal and postnatal growth and adiposity are associated with adult cortisol levels, and whether early growth and adiposity are related to later cortisol through adult body size. DESIGN: Weight, head circumference (birth), height, and body mass index (BMI) (7 yr); and height, BMI (33 yr), and waist-hip ratio (WHR) (45 yr) were measured in the 1958 British birth cohort. SETTING: All study subjects were born in England, Scotland, and Wales in 1 wk in March 1958. PARTICIPANTS: A total of 6,470 participants with salivary cortisol were gathered from 12,069 invitees (54%) at 45 yr. MAIN OUTCOME MEASURES: Two saliva samples on 1 d were collected: 45 min postwaking (t1) and 3 h later (t2). Three cortisol outcomes were measured: t1 level, area-under-curve, and abnormal t1-t2 pattern. RESULTS: WHR was associated with all cortisol measures: among men over the WHR range 0.81-1.05, t1 cortisol decreased by approximately 3 nmol/liter, and the risk of an abnormal t1-t2 pattern increased by 77%; for women, over the WHR range 0.69-0.93, the risk of an abnormal t1-t2 pattern increased by 74%. For childhood measures, among males, increasing 7-yr BMI was associated with decreased t1 cortisol and increased risk of an abnormal t1-t2 pattern. Poorer prenatal growth in women, and postnatal growth in both sexes, was associated with increasing area-under-curve. CONCLUSIONS: Smaller head circumference, shorter stature, lower BMI, and WHR are associated with higher cortisol levels.

Adiposity↗

PubMed2006

Neonatal outcomes after prenatal exposure to selective serotonin reuptake inhibitor antidepressants and maternal depression using population-based linked health data.

CONTEXT: Prenatal exposure to selective serotonin reuptake inhibitor (SSRI) antidepressants and maternal depression both alter neonatal health, and distinguishing the effects of each influence remains challenging. OBJECTIVE: To determine whether exposure to SSRIs and depression differs from exposure to maternal depression alone. DESIGN: Using population health data, records of neonatal birth outcomes were linked to records of maternal health and prenatal maternal prescriptions for SSRIs. SETTING: Population of British Columbia, Canada. PARTICIPANTS: Mothers and their infants, representing all live births during a 39-month period (N = 119,547) (1998-2001). MAIN OUTCOME MEASURES: Outcomes from infants of depressed mothers treated with SSRIs (SE-D) were compared with outcomes from infants of depressed mothers not treated with medication (DE) and nonexposed controls. To control for maternal mental illness severity, propensity score matching was used to identify a comparison group of DE mothers who were similar to the SE-D mothers in characteristics in the year preceding and during pregnancy. RESULTS: Fourteen percent of mothers were diagnosed as having depression during their pregnancy, and the incidence of prenatal SSRI exposure increased from 2.3% to 5.0% during a 39-month period. Birth weight and gestational age for SE-D infants were significantly less than for DE infants, as was the proportion of infants born at less than 37 weeks (95% confidence interval [CI], -1 to -64, -0.25 to -0.45, and -0.009 to -0.04, respectively), although differences in the incidence of birth weight less than the 10th percentile for gestational age were not significant. An increased proportion of SE-D infants had neonatal respiratory distress (13.9% vs 7.8%), jaundice (9.4% vs 7.5%), and feeding problems (3.9% vs 2.4%) compared with DE infants (95% CI of difference, 0.042-0.079, 0.003-0.334, and 0.005-0.025, respectively). When outcomes were compared between SE-D and propensity score-matched DE neonates, SE-D was associated with increased incidence of birth weight below the 10th percentile and rates of respiratory distress. CONCLUSION: With linked population health data and propensity score matching, prenatal SE-D exposure was associated with an increased risk of low birth weight and respiratory distress, even when maternal illness severity was accounted for.

Birth Weight↗

PubMed2006

Cancer and occupational exposure to pentachlorophenol and tetrachlorophenol (Canada).

OBJECTIVE: The objective of this study is to assess the carcinogenicity of pentachlorophenol and tetrachlorophenol using data from the BC sawmill workers cohort study. METHODS: The cohort consisted of 27,464 men employed by 14 sawmills for 1 year or more between 1950 and 1995. Fatal (1950-1995) and incident (1969-1995) cancers were identified using national registries. Plant records and systematic interviews with senior employees were used to estimate dermal exposure. Comparisons were made with the general BC population and dose-response relationships were assessed using Poisson regression. RESULTS: There were 1,495 fatal cancer and 2,571 incident cancers. There were no large or statistically significant excesses of any of the specific cancers were observed compared to the general population. Internal analyses showed strong dose-response relationships for non-Hodgkin's lymphoma, multiple myeloma, and kidney cancer. These relationships were strongest when exposure was restricted to pentachlorophenol. The strength of the dose-response increased when exposure was lagged by 20 years. CONCLUSIONS: Dermal exposure to pentachlorophenol was associated with non-Hodgkin's lymphoma, multiple myeloma, and kidney cancer, but not with other cancers of a priori interest.

British Columbia↗

PubMed2006

Health care use associated with work-related musculoskeletal disorders among hospital workers.

INTRODUCTION: The purpose of this study was to investigate if work-related musculoskeletal disorders (WMSDs) are associated with increased health care use, over and above workers' compensation health care benefits, in the period prior to and following a workers' compensation claim indicating gradual progression and declining function associated with musculoskeletal morbidity. METHODS: This study employed secondary analysis of employment data, workers' compensation claim data and provincial (universal) medical services data for a cohort of health care workers; and investigated rates of medical care contacts among injured workers with a WMSD claim (n=549) compared to a matched group of non-claim workers. Predictors of health care contacts were estimated using general linear regression. RESULTS: WMSD injured workers had significantly higher rates of health care contacts associated with a claim compared to non-injured workers, over and above workers compensation health care benefits. In the final multi-variable model, a WMSD claim among injured workers was associated with an estimated 69% (95% CI, 1.50, 1.91) increase in health care use for the 12-month period immediately after the injury date compared to non injured workers. CONCLUSION: The pattern of visits for WMSDs suggests that workers visit general practitioners as part of an ongoing pattern of symptoms, resulting in frequent utilization of health services prior to work disability that is also reflected in health care contacts after return-to-work.

Adult↗

PubMed2006

The influence of birth weight and socioeconomic position on cognitive development: Does the early home and learning environment modify their effects?

OBJECTIVE: To establish whether effects of birth weight and socioeconomic position on cognition are explained or modified by home or learning environments. STUDY DESIGN: Prospective birth cohort (n = 13,980) with math tests at 7, 11, and 16 years of age and qualifications by 33 years of age. RESULTS: For 1 kg increase in birth weight, 7-year math Z score increased 0.23 (0.19 adjusted for parental interest in child's progress) and adult qualifications increased 0.22 (on a 5-point scale). Maternal reading benefited math less among lower than higher birth weights (p < .05). The birth weight effect remained unchanged 7 to 16 years of age. For each increment in social class (4 categories; IV&V to I&II), 7-year math increased 0.19 (0.12 adjusted for parental interest). Benefits of mother's reading and father's interest were greatest in classes IV&V (interaction p < .05). The difference in Z scores between classes I&II to IV&V was 0.57 at 7 years; 1.12 at 16 years of age. Estimates were little affected by home and school factors. Adult qualifications increased 0.40 per unit social class (0.33 adjusted for parental interest). Maternal interest reduced the chances of those from unskilled manual origins gaining few qualifications (p < .05). Similarly, interactions were seen for maternal reading and paternal interest. CONCLUSION: Influences in the home partly underlie associations between social background and cognition, but they do little to explain a birth weight/cognition association.

Adolescent↗

PubMed2006

Work organization and musculoskeletal injuries among a cohort of health care workers.

OBJECTIVES: This study investigated the relationship between work-organization factors (job control, job demands, and workload measures) and the risk of lower-body musculoskeletal injury among health care workers. METHODS: A four-year, retrospective cohort study of 3769 health care workers was carried out in one acute care hospital in the Canadian province of British Columbia. A job-exposure matrix was constructed for the work-organization factors from survey and administrative data and assigned to workers on the basis of their occupation and department of employment. Musculoskeletal injuries resulting in workers' compensation claims were ascertained from the injury database of the hospital's Occupational Health and Safety Department. RESULTS: In the final Poisson models adjusted for demographic and biomechanical factors, an increased risk for compensated musculoskeletal injuries of the lower back and lower limb was related to low job control [relative risk (RR) 1.64, 95% confidence interval (95% CI) 1.08-2.49] and workload defined by working during periods of high absenteeism within a department (RR 2.10, 95% CI 1.61-2.98). The risk also increased with more biomechanical demands in an occupation and with a recent previous injury. CONCLUSIONS: The results indicate that work-organization characteristics (job control and workload) were associated with an increased risk of musculoskeletal injuries resulting in a compensation claim. These associations remained after the effect of demographic and biomechanical factors was taken into consideration. The association with workload measured by departmental levels of absenteeism should be explored further in future studies as reverse causality (musculoskeletal symptoms resulting in absenteeism) could not be fully ruled out in the current study.

Absenteeism↗

PubMed2005

Occupational exposure to noise and mortality from acute myocardial infarction.

BACKGROUND: Exposure to noise is highly prevalent in the workplace, and an etiologic association with cardiovascular disease has been hypothesized. Although there is evidence of hypertension among noise-exposed workers, evidence of heart disease has been less conclusive. METHODS: We identified a cohort of 27,464 blue-collar workers from 14 lumber mills in British Columbia who worked at least 1 year between 1950 and 1995 and who were followed up over the same period. Cumulative noise exposure was quantitatively assessed. Vital status was ascertained from the Canadian Mortality Database. We estimated standardized mortality ratios using the general population as referents, and we estimated relative risks using an internal low-exposure group as controls. To examine acute effects of noise, we assessed relative risks during subjects' working years in lumber mills. Because of the possibility of exposure misclassification as a result of hearing-protector use, we investigated a subgroup that had been employed before widespread use of protectors. RESULTS: During the follow-up period, 2510 circulatory disease deaths occurred. Relative risks for acute myocardial infarction mortality were elevated in the full cohort, with a stronger association in the subgroup without hearing protection. There was an exposure-response trend, with a relative risk in the highest exposed group of 1.5 (95% confidence interval=1.1-2.2). The highest relative risks (2.0-4.0) were observed during subjects' working years. Smoking did not appear to confound these associations. CONCLUSIONS: Chronic exposure to noise levels typical of many workplaces was associated with excess risk for acute myocardial infarction death. Given the very high prevalence of excess noise exposure at work, this association deserves further attention.

British Columbia↗

PubMed2004

Beneath the calm surface: the changing face of physician-service use in British Columbia, 1985/86 versus 1996/97.

BACKGROUND: Although expenditures on health care are continually increasing and often said to be unsustainable, few studies have examined these trends at the level of services delivered to individual patients. We analyzed trends in the various components that contributed to changes in overall expenditures for physician services in British Columbia from 1985/86 to 1996/97. METHODS: We obtained data on all fee-for-service payments to physicians in each study year using the British Columbia Linked Health Data set and analyzed these at the level of individual patients. We disaggregated overall billing levels by year into the following components: number of physicians seen by each patient, number of visits per physician, number of services rendered on each visit and average price of those services. We removed the effect of inflation on fees by adjusting to those in 1988. We used direct age-standardization to isolate and measure the effect of demographic changes. We used the Consumer Price Index to determine the effects of inflation. RESULTS: Total payments to fee-for-service physicians in British Columbia rose 86.3% over the study period. The increase was entirely accounted for by the combined effects of population growth (28.9%), aging (2.1%) and general inflation (41.4%). Service use per capita rose 10.5%; this increase was offset by a decline of 9.4% in inflation-adjusted fees. The average cost of age-adjusted per-capita services rendered by general or family practitioners (GP/FPs) increased very little (3.3%) over the 11-year period, compared with a nearly one-third (31.8%) increase for medical specialists. Although there was a dramatic increase in the number of GP/FPs seen on average by each patient (32.9%), this increase was offset by the combination of decreases in the number of visits per physician (-14.9%), the number of services provided per visit (-8.0%) and the "real cost" of each service provided (-3.5%). Visits to medical specialists increased by about 20% over the study period in all age groups. However, for each person 65 years of age or over receiving any services, the average fee-adjusted expenditures increased 24.8%, almost 4 times the rate of increase for people younger than 65. The use of surgical services grew 26.5% for seniors while declining -2.0% for people under age 65. INTERPRETATION: These findings suggest a form of "homeostasis" in aggregate-level service use and cost. The supposed inflationary effects of population aging and increasing "abuse of the system" by patients were not found.

Adolescent↗

PubMed2004

Gaseous air pollutants and asthma hospitalization of children with low household income in Vancouver, British Columbia, Canada.

Associations of gaseous air pollutants (including carbon monoxide, sulfur dioxide, nitrogen dioxide, and ozone) with asthma hospitalization, stratified by sex and socioeconomic status, were examined among children 6-12 years of age in Vancouver, British Columbia, Canada, between 1987 and 1998. Relative risks for an exposure increment corresponding to the interquartile range for each gaseous air pollutant were estimated for asthma hospitalization after adjustment for weather conditions, including daily maximum and minimum temperatures as well as average relative humidity. Similar results were obtained by using locally weighted smoothing functions (LOESS) with default convergence criteria and by using natural cubic splines with a more stringent setting. Exposures to nitrogen dioxide were found to be significantly and positively associated with asthma hospitalization for males in the low socioeconomic group but not in the high socioeconomic group. For females, this same pattern of association was observed for exposures to sulfur dioxide. No significantly positive associations were found between carbon monoxide and ozone and asthma hospitalization in either low or high socioeconomic groups.

Air Pollutants↗

PubMed2004

A longitudinal study comparing the effort-reward imbalance and demand-control models using objective measures of physician utilization.

BACKGROUND: The objectives of this study were to compare the predictive validity of the demand-control and effort-reward imbalance models using objective measures of physician utilization. METHODS: Self-reports for psychosocial work conditions were obtained in interviews with 1,028 workers using the demand-control and effort-reward imbalance models. Physician utilization outcomes were obtained through linkage to the British Columbia Linked Health Database. Outcomes were any visit to a physician for mental health reasons and 30 or more physician visits for any reason. The predictive validity of both models was compared in a longitudinal study using logistic regression. RESULTS: Neither job strain nor effort-reward imbalance predicted either outcome. However, low esteem reward and low status control increased the risk for 30 or more physician visits by, respectively, approximately 60% and 30%. CONCLUSIONS: In a sample of middle-aged blue-collar current and ex-sawmill workers in Western Canada, followed prospectively, after controlling for sociodemographic and workplace confounders, and reducing the potential for adverse health selection into high-stress jobs, low esteem reward and low status control were associated with a significantly greater risk for 30 or more physician visits for any reason.

Adult↗

PubMed2003

A comparison between the effort-reward imbalance and demand control models.

BACKGROUND: To compare the predictive validity of the demand/control and reward/imbalance models, alone and in combination with each other, for self-reported health status and the self-reported presence of any chronic disease condition. METHODS: Self-reports for psychosocial work conditions were obtained in a sample of sawmill workers using the demand/control and effort/reward imbalance models. The relative predictive validity of task-level control was compared with effort/reward imbalance. As well, the predictive validity of a model developed by combining task-level control with effort/reward imbalance was determined. Logistic regression was utilized for all models. RESULTS: The demand/control and effort/reward imbalance models independently predicted poor self-reported health status. The effort-reward imbalance model predicted the presence of a chronic disease while the demand/control model did not. A model combining effort-reward imbalance and task-level control was a better predictor of self-reported health status and any chronic condition than either model alone. Effort reward imbalance modeled with intrinsic effort had marginally better predictive validity than when modeled with extrinsic effort only. CONCLUSIONS: Future work should explore the combined effects of these two models of psychosocial stress at work on health more thoroughly.

Adaptation, Psychological↗

PubMed2003

A time-series study of air pollution, socioeconomic status, and mortality in Vancouver, Canada.

We evaluated the relationship between daily levels of particulate and gaseous phase pollutants and mortality within a dynamic cohort of approximately 550,000 individuals whose vital status was ascertained between 1986 and 1999. Time-series methods were applied to evaluate whether there were differential pollutant effects on daily aggregated numbers of deaths in the cohort that was stratified into quintiles of income as defined by the 1991 and 1996 Canadian censuses. The percent change in all-cause, cardiovascular, respiratory, and cancer daily mortality was calculated in relation to short-term changes in levels of a number of particulate (PM(2.5), PM(10-2.5), total suspended particle co-efficient of haze PM(10), SO(4)) and gaseous (O(3), CO, SO(2), NO(2)) pollutants. The estimated effects of air pollution on mortality were adjusted for day of week effects, and several meteorologic variables including temperature, change in barometric pressure, and relative humidity. Several gaseous pollutants were associated with an increased risk of mortality. Specifically for an increase equivalent to the difference between the 90th and 10th percentiles, the estimated percent change in daily mortality based on the 3-day average of NO(2), and SO(2) was 4.0% and 1.3%, respectively. The corresponding changes in mortality associated with SO(2) were much higher when analyses were restricted to death from respiratory disease. Specifically, a difference between the 90th and 10th percentiles was associated with a 5.6% (95% CI= -0.7% to 12.3%). The daily mean coarse fraction (PM(10-2.5)) was associated with increased cardiovascular mortality (estimated change=5.9%, 95% CI=1.1-10.8%). PM(2.5) was not found to be an important predictor of mortality. For NO(2), CO, and SO(2), there was some suggestion of increased risk of all-cause and cardiovascular mortality at lower levels of socioeconomic status. However, these results should be interpreted cautiously due to the small number of deaths observed within each stratum of socioeconomic status.

Aged↗

PubMed2003

Health and human development: understandings from life-course research.

It is now well understood that life-course factors affect a diverse range of outcomes, from general well-being to physical functioning and chronic diseases. Exposure to both beneficial and adverse circumstances over the life course will vary for each individual and will constitute a unique life exposure trajectory, which will manifest as different expressions of health and well-being. Here, we present a 3-fold model of life-course influences on health: latency, cumulative, and pathway. By latency we mean relationships between an exposure at one point in the life course and the probability of health expressions years or decades later, irrespective of intervening experience. Cumulative refers to multiple exposures over the life course whose effects on health combine. Finally, pathways represent dependent sequences of exposures in which exposure at 1 stage of the life course influences the probability of other exposures later in the life course, as well as associated expressions. Evidence demonstrating these relationships suggests that, without a consideration of early life as well as adult life experience, policies designed to improve health status tend to overlook root causes.

Animals↗

PubMed2003

Conspicuous consumption: characterizing high users of physician services in one Canadian province.

OBJECTIVES: To examine medical care use and costs, patterns of morbidity and co-morbidity, and other patient characteristics of high users of physician services in British Columbia. METHODS: This population-based study uses physician claims, hospital discharge summaries and vital statistics data linked at the level of the individual to compare characteristics of high users, other users and non-users of physician services in the Province of British Columbia, Canada. The study included all enrolled adults in the universal health care plan during fiscal year 1996/97. High users were defined as the most costly 5% of users of fee-reimbursed services. Key variables included age, sex, an ecological socio-economic status indicator and a comprehensive set of morbidity indicators, derived from the diagnoses recorded on the utilization records. RESULTS: The top 5% of users consumed a disproportionate 30% of spending on physician services. High users were overwhelmingly characterized by a significant burden of morbidity. Over 80% had at least six different types of morbidity during the study year compared with fewer than 20% of other users. High users were also much more likely to have major diagnoses that were both acute and chronic in nature. Co-morbidity involving psychosocial and chronic medical conditions was also very common. CONCLUSIONS: High users of physician services are overwhelmingly characterized by multiple and complex health problems. Policy tools based on a philosophy of deterrence such as cost-sharing are unlikely to have much impact on their costs and will likely do considerable harm.

Adolescent↗

PubMed2002

Birth weight, childhood socioeconomic environment, and cognitive development in the 1958 British birth cohort study.

OBJECTIVES: To examine the combined effect of social class and weight at birth on cognitive trajectories during school age and the associations between birth weight and educational outcomes through to 33 years. DESIGN: Longitudinal, population based, birth cohort study. PARTICIPANTS: 10 845 males and females born during 3-9 March 1958 with information on birth weight, social class, and cognitive tests. MAIN OUTCOME MEASURES: Reading, maths, draw a man, copying designs, verbal and non-verbal ability tests at ages 7, 11, and 16, highest qualifications achieved by 33, and trajectories of maths standardised scores at 7-16 years. RESULTS: The outcome of all childhood cognitive tests and educational achievements improved significantly with increasing birth weight. Analysis of maths scores at 7 and of highest qualifications achieved by 33 showed that the relations were robust to adjustment for potential confounding factors. For each kilogram increase in birth weight, maths z score increased by 0.17 (adjusted estimate 0.15, 95% confidence interval 0.10 to 0.21) for males and 0.21 (0.20, 0.14 to 0.25) for females. Trajectories of maths z scores between 7 and 16 years diverged for different social class groups: participants from classes I and II increased their relative position on the score with increasing age, whereas classes IV and V showed a relative decline with increasing age. Birth weight explained much less of the variation in cognition than did social class (range 0.5-1.5% v 2.9-12.5%). CONCLUSIONS: The postnatal environment has an overwhelming influence on cognitive function through to early adulthood, but these strong effects do not explain the weaker but independent association with birth weight.

Adolescent↗

PubMedDate not supplied

Neighborhood income and physical and social disorder in Canada: associations with young children's competencies.

This study examined the association of census level, observational, and parent-reported neighborhood characteristics on the verbal and behavioral competencies of a national sample of Canadian preschoolers (N = 3,350). Children's verbal ability scores were positively associated with residing in neighborhoods with affluent residents and negatively associated with residing in neighborhoods with poor residents and in neighborhoods with low cohesion, even after controlling for family socioeconomic factors. Behavior problem scores were higher when children lived in neighborhoods that had fewer affluent residents, high unemployment rates, and neighborhoods with low cohesion, after controlling for family socioeconomic factors. These findings are discussed in light of neighborhood studies of children in the United States in the mid-1990s.

Aggression↗