Youlian Liao

Factors Explaining Excess Stroke Prevalence in the US Stroke Belt

Background and Purpose— Higher risk and burden of stroke have been observed within the southeastern states (the Stroke Belt) compared with elsewhere in the United States. We examined reasons for these disparities using a large data set from a nationwide cross-sectional study. Methods— Self-reported data from the 2005 and 2007 Behavioral Risk Factor Surveillance System were used (n=765 368). The potential contributors for self-reported stroke prevalence (n=27 962) were demographics (age, sex, geography, and race/ethnicity), socioeconomic status (education and income), common risk factors (smoking and obesity), and chronic diseases (hypertension, diabetes, and coronary heart disease). Multivariate logistic regression was used in the analysis. Results— The age- and sex-adjusted OR comparing self-reported stroke prevalence in the 11-state Stroke Belt versus non-Stroke Belt region was 1.25 (95% CI, 1.19 to 1.31). Unequal black/white distribution by region accounted for 20% of the excess prevalence in the Stroke Belt (OR reduced to 1.20; 1.15 to 1.26). Approximately one third (32%) of the excess prevalence was accounted either by socioeconomic status alone or by risk factors and chronic disease alone (OR, 1.12). The OR was further reduced to 1.07 (1.02 to 1.13) in the fully adjusted logistic model, a 72% reduction. Conclusions– Differences in socioeconomic status, risk factors, and prevalence of common chronic diseases account for most of the regional differences in stroke prevalence.

Hepatitis B Testing and Vaccination Among Vietnamese- and Cambodian-Americans

We determined hepatitis B virus (HBV) testing and vaccination levels and factors associated with testing and vaccination among Vietnamese- and Cambodian-Americans. We also examined factors associated with healthcare professional (HCP)-patient discussions about HBV. We analyzed 2006 Racial and Ethnic Approaches to Community Health (REACH) 2010 Risk Factor Survey data from four US communities. We used logistic regression to identify variables associated with HBV vaccination, testing, and HCP-patient discussions about HBV. Of the 2,049 Vietnamese- and Cambodian-American respondents, 60% reported being tested for HBV, 35% reported being vaccinated against hepatitis B, and 36% indicated that they had discussed HBV with a HCP. Cambodian-Americans were less likely than Vietnamese-Americans to have been tested for HBV, while respondents with at least a high school diploma were more likely to have been tested for HBV. Respondents born in the US, younger individuals, and respondents with at least some college education were more likely to have been vaccinated against hepatitis B. HBV testing and vaccination remain suboptimal among members of these populations. Culturally sensitive efforts that target Vietnamese- and Cambodian-Americans for HBV testing and vaccination are needed to identify chronic carriers of HBV, prevent new infections, and provide appropriate medical management. HCPs that serve these populations should be encouraged to discuss HBV with their patients.

Decreases in Smoking Prevalence in Asian Communities Served by the Racial and Ethnic Approaches to Community Health (REACH) Project

OBJECTIVES We examined trends in smoking prevalence from 2002 through 2006 in 4 Asian communities served by the Racial and Ethnic Approaches to Community Health (REACH) intervention. METHODS Annual survey data from 2002 through 2006 were gathered in 4 REACH Asian communities. Trends in the age-standardized prevalence of current smoking for men in 2 Vietnamese communities, 1 Cambodian community, and 1 Asian American/Pacific Islander (API) community were examined and compared with nationwide US and state-specific data from the Behavioral Risk Factor Surveillance System. RESULTS Prevalence of current smoking decreased dramatically among men in REACH communities. The reduction rate was significantly greater than that observed in the general US or API male population, and it was greater than reduction rates observed in the states in which REACH communities were located. There was little change in the quit ratio of men at the state and national levels, but there was a significant increase in quit ratios in the REACH communities, indicating increases in the proportions of smokers who had quit smoking. CONCLUSIONS Smoking prevalence decreased in Asian communities served by the REACH project, and these decreases were larger than nationwide decreases in smoking prevalence observed for the same period. However, disparities in smoking prevalence remain a concern among Cambodian men and non-English-speaking Vietnamese men; these subgroups continue to smoke at a higher rate than do men nationwide.

Cardiovascular Risk Factors and Knowledge of Symptoms Among Vietnamese Americans

BACKGROUNDThere are few population-based studies of cardiovascular risk factors, knowledge, and related behaviors among Vietnamese Americans.OBJECTIVETo describe cardiovascular risk factors, knowledge, and related behaviors among Vietnamese Americans and compare the results to non-Hispanic whites.DESIGNComparison of data from two population-based, cross-sectional telephone surveys.PARTICIPANTSVietnamese Americans in Santa Clara County, California, and non-Hispanic whites in California, aged 18 and older.MEASUREMENTSSurvey measures included sociodemographics, diagnoses, body mass index, fruit and vegetable intake, exercise, and tobacco use. Knowledge of symptoms of heart attack and stroke was collected for Vietnamese Americans.MAIN RESULTSCompared to non-Hispanic whites (n = 19,324), Vietnamese Americans (n = 4,254) reported lower prevalences of obesity, diabetes mellitus, coronary heart disease, and hypertension, and similar prevalences of stroke and hypercholesterolemia. Fewer Vietnamese Americans consumed fruits and vegetables five or more times daily (27.8% vs 16.3%, p < 0.05), and more reported no moderate or vigorous physical activity (12.1% vs 40.1%, p < 0.05). More Vietnamese men than non-Hispanic White men were current smokers (29.8% vs 19.0%, p < 0.05). Vietnamese Americans who spoke Vietnamese were more likely than those who spoke English to eat fruits and vegetables less frequently, engage in no moderate or vigorous physical activity, and, among men, be current smokers. Only 59% of Vietnamese Americans knew that chest pain was a symptom of heart attack.CONCLUSIONSThere are significant disparities in risk factors and knowledge of symptoms of cardiovascular diseases among Vietnamese Americans. Culturally appropriate studies and interventions are needed to understand and to reduce these disparities.

Decreasing disparity in cholesterol screening in minority communities—findings from the Racial and Ethnic Approaches to Community Health 2010

Background Highly controlled research projects demonstrated success in preventing and controlling cardiovascular diseases. Community-based programs have yet to demonstrate significant influence. Data on large-scale community-level interventions targeting minority communities are limited. The aim of this study is to measure the impact of the Racial and Ethnic Approaches to Community Health (REACH 2010) project, a community-based intervention to eliminate racial/ethnic disparities in blood cholesterol screening in minority communities. Methods Annual survey data from 2001 to 2006 were gathered in 22 communities. Trends in the prevalence of age-standardised blood cholesterol screening were examined for four racial/ethnic groups (black, Hispanic, Asian and American Indian/Alaska Native), stratified by education level, and compared with national data from the Behavioral Risk Factor Surveillance System. Results The prevalence of cholesterol screening increased among persons in black, Hispanic and Asian REACH communities (p<0.001), whereas prevalence decreased in the total US and Hispanic populations (p<0.001) and remained similar among blacks and Asians nationwide. The relative disparity between the total US population and most REACH communities decreased (p<0.05). Relative disparity in cholesterol screening related to education level decreased (p<0.05) within REACH communities, whereas relative disparity related to education level nationwide remained similar in blacks and increased (p<0.001) in Hispanics. Conclusion The REACH project decreased racial and ethnic disparities in cholesterol screening between REACH communities and the total US population, as well as disparities related to education level within REACH communities.

Models for count data with an application to Healthy Days measures: are you driving in screws with a hammer?

Introduction Count data are often collected in chronic disease research, and sometimes these data have a skewed distribution. The number of unhealthy days reported in the Behavioral Risk Factor Surveillance System (BRFSS) is an example of such data: most respondents report zero days. Studies have either categorized the Healthy Days measure or used linear regression models. We used alternative regression models for these count data and examined the effect on statistical inference. Methods Using responses from participants aged 35 years or older from 12 states that included a homeownership question in their 2009 BRFSS, we compared 5 multivariate regression models — logistic, linear, Poisson, negative binomial, and zero-inflated negative binomial — with respect to 1) how well the modeled data fit the observed data and 2) how model selections affect inferences. Results Most respondents (66.8%) reported zero mentally unhealthy days. The distribution was highly skewed (variance = 58.7, mean = 3.3 d). Zero-inflated negative binomial regression provided the best-fitting model, followed by negative binomial regression. A significant independent association between homeownership and number of mentally unhealthy days was not found in the logistic, linear, or Poisson regression model but was found in the negative binomial model. The zero-inflated negative binomial model showed that homeowners were 24% more likely than nonowners to have excess zero mentally unhealthy days (adjusted odds ratio, 1.24; 95% confidence interval, 1.08–1.43), but it did not show an association between homeownership and the number of unhealthy days. Conclusion Our comparison of regression models indicates the importance of examining data distribution and selecting models with appropriate assumptions. Otherwise, statistical inferences might be misleading.

Does Perceived Neighborhood Walkability and Safety Mediate the Association Between Education and Meeting Physical Activity Guidelines

The role of neighborhood walkability and safety in mediating the association between education and physical activity has not been quantified. We used data from the 2010 and 2012 Communities Putting Prevention to Work Behavioral Risk Factor Surveillance System and structural equation modeling to estimate how much of the effect of education level on physical activity was mediated by perceived neighborhood walkability and safety. Neighborhood walkability accounts for 11.3% and neighborhood safety accounts for 6.8% of the effect. A modest proportion of the important association between education and physical activity is mediated by perceived neighborhood walkability and safety, suggesting that interventions focused on enhancing walkability and safety could reduce the disparity in physical activity associated with education level.

Improving actions to control high blood pressure in Hispanic communities — Racial and Ethnic Approaches to Community Health Across the U.S. Project, 2009–2012

BACKGROUND Compared with the general population in the United States (U.S.), Hispanics with hypertension are less likely to be aware of their condition, to take antihypertensive medication, and to adopt healthy lifestyles to control high blood pressure. We examined whether a multi-community intervention successfully increased the prevalence of actions to control hypertension among Hispanics. METHODS Annual survey from 2009-2012 was conducted in six Hispanic communities in the Racial and Ethnic Approaches to Community Health (REACH) Across the U.S. PROJECT The survey used address based sampling design that matched the geographies of intervention program. RESULTS Age- and sex-standardized prevalences of taking hypertensive medication, changing eating habits, cutting down on salt, and reducing alcohol use significantly increased among Hispanics with self-reported hypertension in REACH communities. The 3-year relative percent increases were 5.8, 6.8, 7.9, and 35.2% for the four indicators, respectively. These favorable (healthier) trends occurred in both foreign-born and U.S.-born Hispanics. CONCLUSION This large community-based participatory intervention resulted in more Hispanic residents in the communities taking actions to control high blood pressure.

Summarizing health-related quality of life (HRQOL): development and testing of a one-factor model

BackgroundHealth-related quality of life (HRQOL) is a multi-dimensional concept commonly used to examine the impact of health status on quality of life. HRQOL is often measured by four core questions that asked about general health status and number of unhealthy days in the Behavioral Risk Factor Surveillance System (BRFSS). Use of these measures individually, however, may not provide a cohesive picture of overall HRQOL. To address this concern, this study developed and tested a method for combining these four measures into a summary score.MethodsExploratory and confirmatory factor analyses were performed using BRFSS 2013 data to determine potential numerical relationships among the four HRQOL items. We also examined the stability of our proposed one-factor model over time by using BRFSS 2001–2010 and BRFSS 2011–2013 data sets.ResultsBoth exploratory factor analysis and goodness of fit tests supported the notion that one summary factor could capture overall HRQOL. Confirmatory factor analysis indicated acceptable goodness of fit of this model. The predicted factor score showed good validity with all of the four HRQOL items. In addition, use of the one-factor model showed stability, with no changes being detected from 2001 to 2013.ConclusionInstead of using four individual items to measure HRQOL, it is feasible to study overall HRQOL via factor analysis with one underlying construct. The resulting summary score of HRQOL may be used for health evaluation, subgroup comparison, trend monitoring, and risk factor identification.

Reduced Prevalence of Obesity in 14 Disadvantaged Black Communities in the United States: A Successful 4-Year Place-Based Participatory Intervention

OBJECTIVES To assess the impact of a large-scale place-based intervention on obesity prevalence in Black communities. METHODS The Racial and Ethnic Approaches to Community Health across the United States (REACH US) project was conducted in 14 predominantly Black communities in California, Illinois, Massachusetts, New York, Ohio, Pennsylvania, South Carolina, Virginia, Washington, and West Virginia. We measured trends from 2009 to 2012 in the prevalence of obesity. We used Behavioral Risk Factor Surveillance System data to compare these trends with trends among non-Hispanic Whites and non-Hispanic Blacks in the United States and in the 10 states where REACH communities were located, and with a propensity score-matched national sample of non-Hispanic Blacks. RESULTS The age-standardized prevalence of obesity decreased in REACH US communities (P = .045), but not in the comparison populations (P = .435 to P = .996). The relative change was -5.3% in REACH US communities versus +2.4% in propensity score-matched controls (P value for the difference = .031). The net effect on the reduction of obesity prevalence was about 1 percentage point per year for REACH. CONCLUSIONS Obesity prevalence was reduced in 14 disadvantaged Black communities that participated in the REACH project.