Table of Contents

Women's Health Initiative Classification Criteria for Cardiovascular Disease Events
Cross-level Interaction Multiple Imputation Table S1 . Standardized mean differences of participant characteristics between complete cases and original eligible sample of women tracy86@example.net. Table S2 . Correlation Matrix of Socioeconomic Indicators. Table S3 . Baseline population characteristics by cardiovascular event incidence. Table S4 . Estimated hazard ratios for time to first cardiovascular event associated with 5 μg/m 3 higher exposure to PM 2.5 , by different levels of covariate adjustment and with additional adjustment for each socioeconomic measure. Table S5 . Estimated hazard ratios for time to first cardiovascular event associated with 5 μg/m 3 higher exposure to baseline PM 2.5 from multiple imputation analysis. Figure S1 . Scatter plot of first predicted annual average PM 2.5 by neighborhood socioeconomic status (NSES) score with a locally weighted scatterplot smoothing (LOWESS) curve. For most participants, the first available PM 2.5 prediction was the baseline prediction; otherwise, the next available non-missing PM 2.5 prediction was used. The outcome of interest in this study included time to first cardiovascular event (defined as myocardial infarction (MI), stroke, and death from coronary heart disease (CHD) or cerebrovascular disease). An algorithm that incorporated elements of the medical history, electrocardiogram readings, and results of cardiac enzyme/troponin determinations were used to identify and categorize MI's into definite or possible MI's. 21 Strokes included persistent neurological deficit of more than 24 hour duration, due to obstruction or rupture in the brain arterial system. Deaths due to coronary heart disease include deaths due to definite MI's and to definite or possible CHD. Definite fatal CHD were those with no known non-atherosclerotic cause and chest pain within the 72 hours of death and/or a history of chronic disease (with no valvular heart disease or non-ischemic cardiomyopathy). Possible atherosclerotic cardiac disease death was defined as those with no known non-atherosclerotic cause that were consistent with CHD as an underlying cause.
Cross-level interaction
Cross-level interactions were explored in sensitivity analyses. On the individual level, participant education (HS/trade school/GED or less vs. some college or more) and income (<$50,000 vs.
Cross-level interaction
$50,000 or more) were dichotomized. All neighborhood socioeconomic status (NSES) characteristics were dichotomized at the median. For each NSES characteristic and individual-level education or income, participants were categorized as low on both levels (low/low), low on one level and high on the other (low/high), and high on both levels. We were unable to separate out those who had discordant socioeconomic status (SES) levels as low individual SES/high NSES or vice versa due to small numbers. The relationship between long-term annual average PM2.5 exposure and time until incident cardiovascular events was assessed using Cox proportional hazards models. Potential effect modification by SES was investigated by fitting multiplicative interaction terms for different levels of the SES variable with PM2.5. All models except for the NSES score models adjusted for age, Figure S1 . There was no evidence that having low education and low NSES conferred greater disadvantage than having low SES on only one level. However, there is evidence that the association between PM2.5 and CVD is the greatest among those with low income and low NSES, even more so than those who have low SES on only one level.
Multiple imputation
Multiple imputation analyses included 60,744 women who did not have CVD at baseline and did not have missing baseline PM2.5 predictions. These analyses were conducted using baseline PM2.5
Multiple imputation
instead of time-weighted PM2.5 for computational feasibility. Missing values in all SES indicators and covariates were multiply imputed 5 times using chained equations in Stata 13 (StataCorp 2013). The relationship between long-term annual average PM2.5 exposure and time from enrollment until incident cardiovascular events was assessed using Cox proportional hazards models. The same baseline characteristics were controlled for as potential confounders as in the main analysis: age, race/ethnicity, diabetes, hypertension, hypercholesterolemia, smoking (smoking status, cigarettes per day, years smoked), and body mass index. Analyses were stratified by 5 year age categories, body mass index (5 categories), and diabetes status for a more thorough adjustment. 

{'paper_id': '4840882', 'title': 'Individual and Neighborhood Socioeconomic Status and the Association between Air Pollution and Cardiovascular Disease', 's2_url': 'https://api.semanticscholar.org/CorpusID:4840882', 'source': 'S2ORC'}