Willaim Chan
Biographic Data
| ID | 120949 |
|---|---|
| NAME | Willaim Chan |
| GIVEN NAMES | Willaim |
| FAMILY NAME | Chan |
| SIGNATURE | CHAN W |
| AFFILIATIONS | The University of Texas Health Science Center at Houston |
| ORCID | 0000-0003-3329-5282 |
| VERIFIED | Yes |
| TOTAL WORKS | 21 |
| TOTAL CITATIONS | 4 |
| AUTHOR COUNT | 21 |
| EDITOR COUNT | 0 |
| FIRST PUBLICATION YEAR | 1996 |
| LATEST PUBLICATION YEAR | 2026 |
| H-INDEX | 1 |
Untangling Impacts of Socioeconomic Position, Chronic Disease, and Low-Level PM2.5 Exposure on Mortality Among Native American Medicare Beneficiaries
Ambient fine particulate matter (PM2.5) is associated with increased mortality at concentrations below current regulatory standards. Studies of low-level exposure often rely on large administrative cohorts whose geographic and demographic composition may influence observed associations. In a prior analysis, we observed an association between long-term PM2.5 and all-cause mortality among Native American Medicare beneficiaries living in zip codes w…
Low-Level PM2.5 Exposure and Mortality in the Medicare Cohort
Fine particulate matter (PM 2.5 ) has been associated with mortality at low concentrations, with higher per-unit risk at lower exposure levels, and no threshold of effect. We examined characteristics of Medicare decedents living in zip codes at the lowest end of the U.S. PM 2.5 exposure distribution to determine whether there is a demographic, health or exposure profile of beneficiaries for whom even low PM 2.5 exposure is associated with increas…
Domains of Housing Instability and Intimate Partner Violence Risk Among U.S. Tenants
While IPV is often studied as a predictor of housing insecurity, few U.S. studies explore how different forms of housing instability may contribute to intimate partner violence (IPV) risk. Using a mixed-methods approach and a cross-sectional design, this study examined the association between four housing instability domains and IPV among a sample of tenants that had either experienced eviction or were at high risk for eviction. Tenants in Harris…
Does hospital location matter? Association of neighborhood socioeconomic disadvantage with hospital quality in US metropolitan settings
An aspect of a hospital's location, such as its degree of socioeconomic disadvantage, could potentially affect quality ratings of the hospital; yet, few studies have granularly explored this relationship in United States (US) metropolitan areas characterized by a wide breadth of socioeconomic disparities across neighborhoods. An understanding of the effect of neighborhood socioeconomic disadvantage on hospital quality of care is informative for t…
Associations between Physiological Biomarkers and Psychosocial Measures of Pregnancy-Specific Anxiety and Depression with Support Intervention
Stress and anxiety significantly impact the hypothalamic-pituitary axis, and in pregnancy, the subsequent maternal-fetal response can lead to poor outcomes. The objective of this study was to assess the association between psychosocial measures of pregnancy-specific anxiety and physiologic inflammatory responses. Specifically, to determine the effectiveness of the Mentors Offering Maternal Support (M-O-M-S TM ) program to reduce psychosocial anxi…
A Mixed-Methods Study to Examine the Role of Psychosocial Stress and Air Pollution on Hypertension in Mexican-Origin Hispanics
Our findings add to the evidence of a positive association between individual and family stressors on hypertension among Hispanics and other racial/ethnic groups. Contrary to previous studies reporting positive associations, our results suggest that long-term exposure to O 3 may be inversely related to prevalent hypertension
Parent—Adolescent Relationship Education (Pare)
The first author recruited parent-adolescent dyads (N = 192) into after-school prevention education groups at middle schools in southeast Texas. This author placed participants in either (1) an Interactive Program (IP) in which they roleplayed, practiced resistance skills, and held parent-child discussions or (2) an Attention Control Program (ACP) that used the same curriculum but was delivered in a traditional, didactic format. Questionnaires ad…
Special Reviewers
Determinants of the demand for breast cancer screening among women veterans in the United States
Sexual Risk Attitudes and Intentions of Youth Aged 12—14 Years
In this study, the authors compared differences in sexual risk attitudes and intentions for three groups of youth (experimental program, n = 90; attention control, n = 80; and nonparticipant control, n = 634) aged 12-14 years. Two student groups participated with their parents in programs focused on strengthening family interaction and prevention of sexual risks, HIV, and adolescent pregnancy. Surveys assessed students' attitudes and intentions r…
Behavioral change for blood pressure control among urban and rural adults in Taiwan
In exploring the mechanisms of behavioral change for hypertension control, a study based on the transtheoretical model was carried out in Taiwan in 2000, with a sample of 350 hypertensive adults living in Taipei urban and rural areas. The relationships among stages of change, processes of change, and demographic factors were analyzed for six health behaviors: low-fat food consumption, alcohol use, smoking, physical activity, weight control and ro…
Utility of different body composition indicators
RMI, impedance or skinfold estimators are necessary for research requiring an accurate description of body composition changes during adolescence and for assessing the role of lean and fat tissue in disease aetiology. A 2-skinfold method is just as effective as the more complicated impedance. Mid-body circumferences are closely related to blood pressures and heart rates, suggesting their importance as indicators of abdominal fat in adolescents
Is obesity associated with poor sleep quality in adolescents
Obesity has reached epidemic proportions in the U.S. and more developed countries, particularly so among adolescents. A substantial impact on public health could be achieved if other factors causing obesity besides the conventional ones of diet and physical activity could be identified and acted upon. The present study investigates whether there is a link between low sleep quality and obesity in a tri‐ethnic, cross‐sectional sample (n = 383) of m…
Blood pressure and sexual maturity in adolescents
This study investigates sexual maturity as a predictor of resting blood pressures independent of other known predictors, in 179 boys and 204 girls 11-16 years of age from the Heartfelt Study. The sample included youth of African (n = 140), Mexican (n = 117), and European and "other" (n = 126) backgrounds. Sexual maturity was assessed during clinical examination of three standard indicators for each sex. Systolic and diastolic blood pressures were…
Blood pressure and sexual maturity in adolescents
This study investigates sexual maturity as a predictor of resting blood pressures independent of other known predictors, in 179 boys and 204 girls 11-16 years of age from the Heartfelt Study. The sample included youth of African (n = 140), Mexican (n = 117), and European and “other” (n = 126) backgrounds. Sexual maturity was assessed during clinical examination of three standard indicators for each sex. Systolic and diastolic blood pressures were…
Strategies for combining and scaling sexual maturity indicators
A single variable should suffice to describe sexual maturity at the studied ages, or variables could be combined in a (unstandardized) sexual maturity index (SMI): SMI (Girls)=0.998 x BREAST+0.900 x PUBIC HAIR + 1.815 x YEARS SINCE MENARCHE. SMI (Boys)= 1.104 x GENITAL + 1.328 x PUBIC HAIR + 5.997 x TESTES SIZE (mL)
Adolescent blood pressure, anger expression and hostility
An uncertain relation between health and angry/hostile behaviour exists in the literature on adolescents. With data from a pilot study, one possible reason for this is explored: health measures such as blood pressure as well as angry/hostile behaviours may change with, or depend upon physical maturity, body size and body fatness. The sample consists of 60 African-, Hispanic-, and Anglo-American adolescents (15 to 16 years of age) drawn from a pub…
Precision of measuring body fat distribution in adolescent African American girls from the ‘healthy growth study’
Precision estimates are given for anthropometric assessment of body fat distribution in participants (n = 86) of the Healthy Growth Study (total n = 154). This five year longitudinal study explored the psychosocial and biologic influences on activity levels in urban adolescent African American girls. The basic anthropometric data include height, weight, four body and limb circumferences, and five skinfold measurements. It is proposed that ratio i…
Conicity
"Conicity" (C) is an index of body fat distribution which expresses an individuals waist circumference relative to the circumference of a cylinder generated with that persons weight and height assuming a constant for body density (Valdez [1991] J. Clin. Epidemiol. 44:955-956). The more central a person is in fat distribution, the higher the value of C. In a pilot study of cardiovascular reactivity and dimensions of anger and hostility in 60 Afric…
Precision of measuring body fat distribution in adolescent African American girls from the ‘healthy growth study’
Precision estimates are given for anthropometric assessment of body fat distribution in participants (n = 86) of the Healthy Growth Study (total n = 154). This five year longitudinal study explored the psychosocial and biologic influences on activity levels in urban adolescent African American girls. The basic anthropometric data include height, weight, four body and limb circumferences, and five skinfold measurements. It is proposed that ratio i…
Conicity
“Conicity” (C) is an index of body fat distribution which expresses an individuals waist circumference relative to the circumference of a cylinder generated with that persons weight and height assuming a constant for body density (Valdez [1991] J. Clin. Epidemiol. 44:955–956). The more central a person is in fat distribution, the higher the value of C. In a pilot study of cardiovascular reactivity and dimensions of anger and hostility in 60 Afric…
Determinants of the demand for breast cancer screening among women veterans in the United States
Does hospital location matter? Association of neighborhood socioeconomic disadvantage with hospital quality in US metropolitan settings
An aspect of a hospital's location, such as its degree of socioeconomic disadvantage, could potentially affect quality ratings of the hospital; yet, few studies have granularly explored this relationship in United States (US) metropolitan areas characterized by a wide breadth of socioeconomic disparities across neighborhoods. An understanding of the effect of neighborhood socioeconomic disadvantage on hospital quality of care is informative for t…
Precision of measuring body fat distribution in adolescent African American girls from the ‘healthy growth study’
Precision estimates are given for anthropometric assessment of body fat distribution in participants (n = 86) of the Healthy Growth Study (total n = 154). This five year longitudinal study explored the psychosocial and biologic influences on activity levels in urban adolescent African American girls. The basic anthropometric data include height, weight, four body and limb circumferences, and five skinfold measurements. It is proposed that ratio i…
Conicity
"Conicity" (C) is an index of body fat distribution which expresses an individuals waist circumference relative to the circumference of a cylinder generated with that persons weight and height assuming a constant for body density (Valdez [1991] J. Clin. Epidemiol. 44:955-956). The more central a person is in fat distribution, the higher the value of C. In a pilot study of cardiovascular reactivity and dimensions of anger and hostility in 60 Afric…
Precision of measuring body fat distribution in adolescent African American girls from the ‘healthy growth study’
Precision estimates are given for anthropometric assessment of body fat distribution in participants (n = 86) of the Healthy Growth Study (total n = 154). This five year longitudinal study explored the psychosocial and biologic influences on activity levels in urban adolescent African American girls. The basic anthropometric data include height, weight, four body and limb circumferences, and five skinfold measurements. It is proposed that ratio i…
Conicity
“Conicity” (C) is an index of body fat distribution which expresses an individuals waist circumference relative to the circumference of a cylinder generated with that persons weight and height assuming a constant for body density (Valdez [1991] J. Clin. Epidemiol. 44:955–956). The more central a person is in fat distribution, the higher the value of C. In a pilot study of cardiovascular reactivity and dimensions of anger and hostility in 60 Afric…
Adolescent blood pressure, anger expression and hostility
An uncertain relation between health and angry/hostile behaviour exists in the literature on adolescents. With data from a pilot study, one possible reason for this is explored: health measures such as blood pressure as well as angry/hostile behaviours may change with, or depend upon physical maturity, body size and body fatness. The sample consists of 60 African-, Hispanic-, and Anglo-American adolescents (15 to 16 years of age) drawn from a pub…
Blood pressure and sexual maturity in adolescents
This study investigates sexual maturity as a predictor of resting blood pressures independent of other known predictors, in 179 boys and 204 girls 11-16 years of age from the Heartfelt Study. The sample included youth of African (n = 140), Mexican (n = 117), and European and "other" (n = 126) backgrounds. Sexual maturity was assessed during clinical examination of three standard indicators for each sex. Systolic and diastolic blood pressures were…
Blood pressure and sexual maturity in adolescents
This study investigates sexual maturity as a predictor of resting blood pressures independent of other known predictors, in 179 boys and 204 girls 11-16 years of age from the Heartfelt Study. The sample included youth of African (n = 140), Mexican (n = 117), and European and “other” (n = 126) backgrounds. Sexual maturity was assessed during clinical examination of three standard indicators for each sex. Systolic and diastolic blood pressures were…
Strategies for combining and scaling sexual maturity indicators
A single variable should suffice to describe sexual maturity at the studied ages, or variables could be combined in a (unstandardized) sexual maturity index (SMI): SMI (Girls)=0.998 x BREAST+0.900 x PUBIC HAIR + 1.815 x YEARS SINCE MENARCHE. SMI (Boys)= 1.104 x GENITAL + 1.328 x PUBIC HAIR + 5.997 x TESTES SIZE (mL)
Is obesity associated with poor sleep quality in adolescents
Obesity has reached epidemic proportions in the U.S. and more developed countries, particularly so among adolescents. A substantial impact on public health could be achieved if other factors causing obesity besides the conventional ones of diet and physical activity could be identified and acted upon. The present study investigates whether there is a link between low sleep quality and obesity in a tri‐ethnic, cross‐sectional sample (n = 383) of m…
Behavioral change for blood pressure control among urban and rural adults in Taiwan
In exploring the mechanisms of behavioral change for hypertension control, a study based on the transtheoretical model was carried out in Taiwan in 2000, with a sample of 350 hypertensive adults living in Taipei urban and rural areas. The relationships among stages of change, processes of change, and demographic factors were analyzed for six health behaviors: low-fat food consumption, alcohol use, smoking, physical activity, weight control and ro…
Utility of different body composition indicators
RMI, impedance or skinfold estimators are necessary for research requiring an accurate description of body composition changes during adolescence and for assessing the role of lean and fat tissue in disease aetiology. A 2-skinfold method is just as effective as the more complicated impedance. Mid-body circumferences are closely related to blood pressures and heart rates, suggesting their importance as indicators of abdominal fat in adolescents
Sexual Risk Attitudes and Intentions of Youth Aged 12—14 Years
In this study, the authors compared differences in sexual risk attitudes and intentions for three groups of youth (experimental program, n = 90; attention control, n = 80; and nonparticipant control, n = 634) aged 12-14 years. Two student groups participated with their parents in programs focused on strengthening family interaction and prevention of sexual risks, HIV, and adolescent pregnancy. Surveys assessed students' attitudes and intentions r…
Special Reviewers
Determinants of the demand for breast cancer screening among women veterans in the United States
Parent—Adolescent Relationship Education (Pare)
The first author recruited parent-adolescent dyads (N = 192) into after-school prevention education groups at middle schools in southeast Texas. This author placed participants in either (1) an Interactive Program (IP) in which they roleplayed, practiced resistance skills, and held parent-child discussions or (2) an Attention Control Program (ACP) that used the same curriculum but was delivered in a traditional, didactic format. Questionnaires ad…
A Mixed-Methods Study to Examine the Role of Psychosocial Stress and Air Pollution on Hypertension in Mexican-Origin Hispanics
Our findings add to the evidence of a positive association between individual and family stressors on hypertension among Hispanics and other racial/ethnic groups. Contrary to previous studies reporting positive associations, our results suggest that long-term exposure to O 3 may be inversely related to prevalent hypertension
Associations between Physiological Biomarkers and Psychosocial Measures of Pregnancy-Specific Anxiety and Depression with Support Intervention
Stress and anxiety significantly impact the hypothalamic-pituitary axis, and in pregnancy, the subsequent maternal-fetal response can lead to poor outcomes. The objective of this study was to assess the association between psychosocial measures of pregnancy-specific anxiety and physiologic inflammatory responses. Specifically, to determine the effectiveness of the Mentors Offering Maternal Support (M-O-M-S TM ) program to reduce psychosocial anxi…
Does hospital location matter? Association of neighborhood socioeconomic disadvantage with hospital quality in US metropolitan settings
An aspect of a hospital's location, such as its degree of socioeconomic disadvantage, could potentially affect quality ratings of the hospital; yet, few studies have granularly explored this relationship in United States (US) metropolitan areas characterized by a wide breadth of socioeconomic disparities across neighborhoods. An understanding of the effect of neighborhood socioeconomic disadvantage on hospital quality of care is informative for t…
Low-Level PM2.5 Exposure and Mortality in the Medicare Cohort
Fine particulate matter (PM 2.5 ) has been associated with mortality at low concentrations, with higher per-unit risk at lower exposure levels, and no threshold of effect. We examined characteristics of Medicare decedents living in zip codes at the lowest end of the U.S. PM 2.5 exposure distribution to determine whether there is a demographic, health or exposure profile of beneficiaries for whom even low PM 2.5 exposure is associated with increas…
Domains of Housing Instability and Intimate Partner Violence Risk Among U.S. Tenants
While IPV is often studied as a predictor of housing insecurity, few U.S. studies explore how different forms of housing instability may contribute to intimate partner violence (IPV) risk. Using a mixed-methods approach and a cross-sectional design, this study examined the association between four housing instability domains and IPV among a sample of tenants that had either experienced eviction or were at high risk for eviction. Tenants in Harris…
Untangling Impacts of Socioeconomic Position, Chronic Disease, and Low-Level PM2.5 Exposure on Mortality Among Native American Medicare Beneficiaries
Ambient fine particulate matter (PM2.5) is associated with increased mortality at concentrations below current regulatory standards. Studies of low-level exposure often rely on large administrative cohorts whose geographic and demographic composition may influence observed associations. In a prior analysis, we observed an association between long-term PM2.5 and all-cause mortality among Native American Medicare beneficiaries living in zip codes w…
Medicine (19 works) · Demography (16 works) · Psychology (10 works) · Internal Medicine (9 works) · Body mass index (8 works) · Environmental health (8 works) · Demography (7 works) · Developmental psychology (6 works) · Blood pressure (5 works) · Anthropometry (4 works)