David Ahn - Academia.edu (original) (raw)

Papers by David Ahn

Archives of Pediatrics and Adolescent Medicine

To provide national estimates of asthma prevalence in African-American, Mexican American and whit... more To provide national estimates of asthma prevalence in African-American, Mexican American and white (non-Latino) children and adolescents using several common definitions; to evaluate familial, sociodemographic, and environmental risk factors that are independently associated with current asthma in children; and to identify subgroups at particular risk for current asthma using 2 complementary data analytic approaches. Cross-sectional study, using the Third National Health and Nutrition Examination Survey, 1988-1994. Eighty-nine mobile examination centers in the United States. Twelve thousand three hundred eighty-eight African American, Mexican American, and white (non-Latino) children and adolescents, aged 2 months through 16 years, selected from a systematic random, population-based, nationally representative sample. Current asthma, defined by caregivers who reported that their child currently had doctor-diagnosed asthma. The overall prevalence of current asthma was 6.7% (95% confidence interval [CI], 5.6-7.8). Odds ratios for current asthma from the multiple regression analysis were 4.00 (95% CI, 2.90-5.52) for children with a parental history of asthma or hay fever, 1.94 (95% CI, 1.09-3.46) for children with body mass index (calculated as weight in kilograms divided by the square of height in meters) greater than or equal to the 85th percentile, and 1.64 (95% CI, 1.20-2.26) for children of African American ethnicity. African American and Mexican American children showed a consistent prevalence of current asthma across age while white children showed an increase in prevalence with age. The 2 highest-risk subgroups identified by the signal detection analysis were composed of children with a parental history of asthma or hay fever who were 10 years or older with a body mass index greater than or equal to the 85th percentile (31.0% current asthma), and children with a parental history who were 10 years or younger and of African American ethnicity (15.6% current asthma). The findings from this analysis show a strong independent association between obesity and current asthma in children and adolescents, and confirm previous reports of a parental history of asthma or hay fever and African American ethnicity as additional important risk factors.

Typescript (photocopy) Thesis (Ph. D.)--Stanford University, 1983. Bibliography: leaves 144-149.

Medicine & Science in Sports & Exercise, 2003

JAMA, 1998

Cardiovascular disease (CVD) risk factors are higher among ethnic minority women than among white... more Cardiovascular disease (CVD) risk factors are higher among ethnic minority women than among white women in the United States. However, because ethnic minority women are disproportionately poor, socioeconomic status (SES) may substantially explain these risk factor differences. To determine whether differences in CVD risk factors by ethnicity could be attributed to differences in SES. Third National Health and Nutrition Examination Survey conducted between 1988 and 1994. Eighty-nine mobile examination centers. A total of 1762 black, 1481 Mexican American, and 2023 white women, aged 25 to 64 years, who completed both the home questionnaire and medical examination. Ethnicity and years of education (SES) in relation to systolic blood pressure, cigarette smoking, body mass index (BMI, a measure of weight in kilograms divided by the square of height in meters), physical inactivity, non-high-density lipoprotein cholesterol (non-HDL-C [the difference between total cholesterol and HDL-C]), and non-insulin-dependent diabetes mellitus. As expected, most CVD risk factors were higher among ethnic minority women than among white women. After adjusting for years of education, highly significant differences in blood pressure, BMI, physical inactivity, and diabetes remained for both black and Mexican American women compared with white women (P<.001). In addition, women of lower SES from each of the 3 ethnic groups had significantly higher prevalences of smoking and physical inactivity and higher levels of BMI and non-HDL-C than women of higher SES (P<.001). These findings provide the greatest evidence to date of higher CVD risk factors among black and Mexican American women than among white women of comparable SES. The striking differences by both ethnicity and SES underscore the critical need to improve screening, early detection, and treatment of CVD-related conditions for black and Mexican American women, as well as for women of lower SES in all ethnic groups.

Cancer Epidemiology Biomarkers & Prevention, 2008

BACKGROUND-Discrimination has been shown as a major causal factor in health disparities, yet litt... more BACKGROUND-Discrimination has been shown as a major causal factor in health disparities, yet little is known about the relationship between perceived medical discrimination (vs. general discrimination outside medical settings) and cancer screening behaviors. We examined whether perceived medical discrimination is associated with lower screening rates for colorectal and breast cancers among racial and ethnic minority adult Californians.

Archives of Pediatrics & Adolescent Medicine, 2002

To provide national estimates of asthma prevalence in African-American, Mexican American and whit... more To provide national estimates of asthma prevalence in African-American, Mexican American and white (non-Latino) children and adolescents using several common definitions; to evaluate familial, sociodemographic, and environmental risk factors that are independently associated with current asthma in children; and to identify subgroups at particular risk for current asthma using 2 complementary data analytic approaches. Cross-sectional study, using the Third National Health and Nutrition Examination Survey, 1988-1994. Eighty-nine mobile examination centers in the United States. Twelve thousand three hundred eighty-eight African American, Mexican American, and white (non-Latino) children and adolescents, aged 2 months through 16 years, selected from a systematic random, population-based, nationally representative sample. Current asthma, defined by caregivers who reported that their child currently had doctor-diagnosed asthma. The overall prevalence of current asthma was 6.7% (95% confidence interval [CI], 5.6-7.8). Odds ratios for current asthma from the multiple regression analysis were 4.00 (95% CI, 2.90-5.52) for children with a parental history of asthma or hay fever, 1.94 (95% CI, 1.09-3.46) for children with body mass index (calculated as weight in kilograms divided by the square of height in meters) greater than or equal to the 85th percentile, and 1.64 (95% CI, 1.20-2.26) for children of African American ethnicity. African American and Mexican American children showed a consistent prevalence of current asthma across age while white children showed an increase in prevalence with age. The 2 highest-risk subgroups identified by the signal detection analysis were composed of children with a parental history of asthma or hay fever who were 10 years or older with a body mass index greater than or equal to the 85th percentile (31.0% current asthma), and children with a parental history who were 10 years or younger and of African American ethnicity (15.6% current asthma). The findings from this analysis show a strong independent association between obesity and current asthma in children and adolescents, and confirm previous reports of a parental history of asthma or hay fever and African American ethnicity as additional important risk factors.

American Journal of Preventive Medicine, 2006

A number of studies have established links between neighborhood social environments and health. I... more A number of studies have established links between neighborhood social environments and health. In a previous study of 8197 adults, death rates for adults with low socioeconomic status (SES) were highest in high-SES neighborhoods, lower in moderate-SES neighborhoods and lowest in low-SES neighborhoods. This study examines whether these findings extend to time to hospitalization. Population-based study of 1686 women and men, aged 25 to 74 at baseline, from 82 neighborhoods in four California cities. Participants were surveyed and medically examined in 1989-1990 and followed through the end of 2002. Neighborhood-level SES was defined by five census variables and divided into three levels. Individual-level SES was defined by household income and educational level and divided into tertiles (nine individual/neighborhood SES groups). There were 627 hospitalizations. The age- and gender-adjusted rates of any hospitalization between 1989-1990 and the end of 2002 for adults with low SES were highest for those living in high-SES neighborhoods (51% compared with 28% to 38% for adults from the other eight individual/neighborhood groups). For these adults, time to hospitalization, as indicated by survival curves, was significantly shorter compared with the other individual/neighborhood groups (p < 0.01, multilevel Cox proportional hazards model). Findings were not explained by baseline differences in individual-level sociodemographic characteristics, health behaviors or risk factors, health status, or proximity to neighborhood goods and services. These findings suggest that factors leading to increased mortality for adults with low SES in high-SES neighborhoods also affect hospitalization.

Cancer Epidemiology Biomarkers & Prevention

Data from a large, population-based case-control study were analyzed to investigate the relations... more Data from a large, population-based case-control study were analyzed to investigate the relationship between prenatal exposure to tobacco smoke and childhood brain tumors (CBTs). A total of 540 CBT patients, diagnosed between 1984 and 1991, were identified from population-based tumor registries in 19 West Coast counties that included Seattle, WA (13 counties), San Francisco, CA (5 counties), and Los Angeles, CA (1 county). Random digit dial was used to select 801 control subjects from the three geographical regions to obtain a case:control ratio of 1:2 in San Francisco and Seattle and 1:1 in Los Angeles. The data first were analyzed separately by geographical site and then were combined with adjustments made for gender, age at the time of diagnosis (or reference date of control subjects), birth year of the index child, and maternal race. No association was found between the risk of CBTs and maternal or paternal smoking before pregnancy and there was no association between CBTs and maternal smoking during pregnancy [odds ratio (OR) = 0.98; 95% confidence interval (CI) = 0.72-1.3]. A slightly increased OR for CBTs was found for paternal smoking during pregnancy in the absence of maternal smoking (OR = 1.2; 95% CI = 0.90-1.5) and for maternal exposure to passive smoke from any source (OR = 1.2; 95% CI = 0.95-1.6). The results of this analysis are consistent with results from several prior epidemiological studies that showed no significant association between CBTs and maternal smoking before or during pregnancy or maternal exposure to passive smoke during pregnancy.

American Journal of Epidemiology

A total of 452 women with cutaneous malignant melanoma and 930 control subjects aged 25-59 years ... more A total of 452 women with cutaneous malignant melanoma and 930 control subjects aged 25-59 years participated in a population-based case-control study carried out in the San Francisco Bay Area between 1981 and 1986. Interviews were conducted in the homes of the women. Questions were asked about various phenotypic characteristics, including eye, hair, and complexion color, presence of freckles, and number of nevi, as well as medical history, history of exposure to sunlight, ability to tan, occupation, use of cigarettes and alcohol, and demographic factors. Histologic type of melanoma was considered in the analysis: 355 (79%) women were diagnosed with superficial spreading melanoma, 61 (13%) had nodular melanoma, 13 (3%) had lentigo maligna melanoma, and 23 (5%) had other melanomas that could not be further classified. For all cutaneous melanoma subjects combined, univariate results related to host factors showed that risk increased with the presence of nevi greater than 5 mm in diame...

Cancer Research

In a case-control study, we explored a potential association between uveal melanoma and reproduct... more In a case-control study, we explored a potential association between uveal melanoma and reproductive factors in women. Responses from telephone interviews of 186 women diagnosed with uveal melanoma were compared with responses of 423 women without this disease. All women resided in 11 U.S. western states. We observed a decreased risk of uveal melanoma for women who had ever been pregnant [relative risk (RR) = 0.60, 95% confidence interval (CI) = 0.37 -0.95], with an increase in this protective effect with more live births after adjustment for age, menopausal status, eye color, and skin sensitivity to the sun (1-2 births, RR = 0.47,95% CI 0.29-0.78; 3-4 births, RR = 0.38, 95% CI = 0.22-0.64; 5 or more births, RR = 0.33, 95% CI = 0.15-0.71). The largest effect was observed between nulliparous and parous women. No other reproductive factors, including use of oral contraceptives or postmenopausal estrogens, were shown to be related to risk for uveal melanoma. We conclude that most repro...

American Journal of Clinical Pathology

The authors reviewed a series of fine-needle aspiration biopsy (FNAB) specimens of the liver to i... more The authors reviewed a series of fine-needle aspiration biopsy (FNAB) specimens of the liver to identify useful cytologic criteria to distinguish hepatocellular carcinoma (HCC) from nonneoplastic liver. Ten cytologic features were examined in this study: high cellularity, acinar pattern, trabecular pattern, hyperchromasia, pleomorphism, irregularly granular chromatin, uniformly prominent nucleoli, multiple nucleoli, increased nuclear/cytoplasmic ratio, and atypical naked hepatocytic nuclei. These features were examined in a series of 82 FNAB specimens from 52 patients with HCC and 30 patients with nonneoplastic lesions. With the use of a step-wise logistic regression analysis, three features were identified as predictive of HCC: increased nuclear/cytoplasmic ratio (P = 0.001), trabecular pattern (P = 0.002), and atypical naked hepatocytic nuclei (P = 0.03). When these three criteria were used, the sensitivity of diagnosing HCC by FNAB was 100%, and the specificity was 87%.

Cancer Research

We conducted a case-control interview study among 1277 subjects (407 patients, 870 controls selec... more We conducted a case-control interview study among 1277 subjects (407 patients, 870 controls selected by using random digit dial) in 11 western United States to determine whether uveal melanoma and cutaneous melanoma shared common risk factors. After adjustment for other factors, the risk of uveal melanoma was increased for those with green, gray, or hazel eyes [relative risk (RR) = 2.5, P less than 0.001] or blue eyes (RR = 2.2, P less than 0.001) when compared to brown. A tendency to sunburn after 0.5 h midday summer sun exposure increased risk for uveal melanoma (burn with tanning RR = 1.5, P = 0.02; burn with little tanning RR = 1.8, P less than 0.001; burn with no tanning RR = 1.7, P = 0.002); as did exposure to UV or black lights (RR = 3.7, P = 0.003); and welding burn, sunburn of the eye, or snow blindness (RR = 7.2, P less than 0.001). An association with uveal melanoma was also noted with an increasing number of large nevi (P = 0.04 for trend), although the individual risk e...

Cancer Research

Forty anal paraffin-embedded tissue specimens from 24 subjects were studied for the presence of h... more Forty anal paraffin-embedded tissue specimens from 24 subjects were studied for the presence of human papillomavirus (HPV) types 6, 11, 16, 18, 31, and 33, herpes simplex virus (HSV), Epstein-Barr virus, and cytomegalovirus DNA by using the polymerase chain reaction. These tissues ranged from histologically normal to invasive squamous cell carcinoma. HPV DNA was detected in the invasive anal cancer tissues of 11 of 13 subjects. HPV types were segregated by histopathological severity, with HPV 16 associated exclusively with high grade anal intraepithelial neoplasia and invasive cancer. HPV types 6 and 11 were associated with condyloma and low grade anal intraepithelial neoplasia. HPV DNA in situ hybridization studies confirmed the presence of HPV DNA in the invasive cancer tissues of 6 of 12 subjects. HPV DNA in these tissues was highly focal and primarily associated with invasive cell nests that demonstrated the greatest degree of squamous differentiation. HSV DNA was detected only ...

American Journal of Epidemiology

Oral contraceptive use and reproductive factors were investigated in a population-based case-cont... more Oral contraceptive use and reproductive factors were investigated in a population-based case-control study of 452 women aged 25-59 years who were diagnosed with cutaneous malignant melanoma during the period 1981-1986 and 930 controls. Ever use of oral contraceptives was reported by 72 percent of melanoma patients and 79 percent of control subjects in this San Francisco Bay Area study, although duration of use was slightly longer for women with superficial spreading melanoma (5.5 years) than for controls (4.3 years). While some subgroups had elevated or reduced odds ratios, no consistent association was observed between cutaneous melanoma risk and oral contraceptive use when use was examined by duration, latency, age at diagnosis, age at first use, and time period of first use. Neither number of live births nor age at birth of the first child was associated with risk for cutaneous melanoma; nor was a history of miscarriage, induced abortion, or endometriosis. No association was obse...

Cancer Epidemiology Biomarkers & Prevention

An analysis of the relationship between the anatomic site of cutaneous melanoma, sun exposure, an... more An analysis of the relationship between the anatomic site of cutaneous melanoma, sun exposure, and phenotype was conducted in 355 women with histologically confirmed superficial-spreading melanoma and in 935 control subjects. The most frequent site for superficial-spreading melanoma was the leg. However, when major sun-related and phenotype risk factors were examined by site, risk ratios were lowest for melanomas that occurred on the leg. A history of frequent sunburns during elementary or high school, increased number of self-assessed large nevi, and blond hair were more strongly associated with melanoma sites other than the leg. Tumors on the trunk were more likely than tumors at other sites to be associated with histological evidence of a preexisting nevus. Results of this work indicate that associations between melanoma phenotypic factors may differ by anatomic site.

American Journal of Epidemiology

A population-based case-control study of cutaneous malignant melanoma (CMM) was conducted in 452 ... more A population-based case-control study of cutaneous malignant melanoma (CMM) was conducted in 452 women with melanoma and 930 control subjects aged 25-59 years in five San Francisco Bay Area counties between 1981 and 1986. Women were interviewed in their homes with regard to history of sunlight exposure and sunburns during different periods in their lives, phenotypic and host characteristics, medical history, occupation, and demographic factors. Data were analyzed by the patients' histologic type of melanoma; 355 women were classified as having superficial spreading melanoma (SSM), 61 had nodular melanoma (NM), 13 had lentigo maligna melanoma, and 23 had other melanomas that could not be further classified upon histologic review by University of California dermatopathologists. Univariate results from analysis of factors related to sun exposure showed that the risk of all histologic types of CMM, SSM, and NM increased with increasing tendency of the subject to sunburn and with his...

American Journal of Epidemiology

To determine risk factors for Ewing's bone sarcoma, the authors interviewed mothers of 43 pat... more To determine risk factors for Ewing's bone sarcoma, the authors interviewed mothers of 43 patients diagnosed between January 1978 and August 1986 and 193 controls in the San Francisco Bay Area, California, regarding medical and occupational history of parents and other factors related to the subjects and their immediate families. Controls were selected by using random digit dial telephone methods. Adjusted relative risk estimates suggest that risks were elevated for children whose fathers were engaged in agricultural occupations during the period from 6 months prior to conception of the subject up to the time of diagnosis for the patients or interview for the controls (relative risk (RR) = 8.8, 95% confidence interval (CI) 1.8-42.7) and for children whose fathers had occupational exposure to herbicides, pesticides, or fertilizers (RR = 6.1, 95% CI 1.7-21.9, p = 0.002). Prior ingestion of poison or an overdose of medication was more common in patients than in controls (RR = 4.4, ...

Annals of internal medicine

To determine the hemopoietic effects of recombinant human granulocyte-macrophage colony-stimulati... more To determine the hemopoietic effects of recombinant human granulocyte-macrophage colony-stimulating factor (GM-CSF) in patients having autologous hemopoietic stem cell transplantation for Hodgkin or non-Hodgkin lymphoma. Placebo or GM-CSF was administered after bone marrow or peripheral blood stem cell transplantation or both in a randomized, double-blind phase III trial by daily intravenous infusion (10 micrograms/kg body weight) until absolute neutrophil counts reached greater than or equal to 1000/mm3 on 3 consecutive days. Bone marrow transplantation unit in a university hospital. Sixty-nine consecutive patients with Hodgkin or non-Hodgkin lymphoma received GM-CSF (36 patients) or placebo (33 patients). Patients who received GM-CSF achieved absolute neutrophil counts greater than or equal to 500/mm3 (median, 12 compared with 16 days, P = 0.02) and absolute neutrophil counts greater than or equal to 1000/mm3 (median, 15 compared with 24 days, P less than 0.001) more quickly than ...

There is a long history of epidemiologists using maps to examine relationships between environmen... more There is a long history of epidemiologists using maps to examine relationships between environments and health. As a result, Geographic Information Systems (GIS) are being increasingly used in epidemiologic research. To raise awareness among epidemiologists and the general public health audience of ways to integrate GIS tools in epidemiologic research, the authors illustrate six tools (defining neighborhood geographic boundaries, determining geographic representation of study participants, determining inclusion/exclusion criteria for analytic variables, calculating distance/density variables for analyses, visualizing change over time in neighborhood physical and demographic environments, and disseminating findings to study communities) that were recently applied in a series of population-based studies of neighborhood environments and cardiovascular disease and mortality. The authors discuss potential applications of each tool and relevant issues to consider. The ultimate aim is to i...

Archives of Pediatrics and Adolescent Medicine

To provide national estimates of asthma prevalence in African-American, Mexican American and whit... more To provide national estimates of asthma prevalence in African-American, Mexican American and white (non-Latino) children and adolescents using several common definitions; to evaluate familial, sociodemographic, and environmental risk factors that are independently associated with current asthma in children; and to identify subgroups at particular risk for current asthma using 2 complementary data analytic approaches. Cross-sectional study, using the Third National Health and Nutrition Examination Survey, 1988-1994. Eighty-nine mobile examination centers in the United States. Twelve thousand three hundred eighty-eight African American, Mexican American, and white (non-Latino) children and adolescents, aged 2 months through 16 years, selected from a systematic random, population-based, nationally representative sample. Current asthma, defined by caregivers who reported that their child currently had doctor-diagnosed asthma. The overall prevalence of current asthma was 6.7% (95% confidence interval [CI], 5.6-7.8). Odds ratios for current asthma from the multiple regression analysis were 4.00 (95% CI, 2.90-5.52) for children with a parental history of asthma or hay fever, 1.94 (95% CI, 1.09-3.46) for children with body mass index (calculated as weight in kilograms divided by the square of height in meters) greater than or equal to the 85th percentile, and 1.64 (95% CI, 1.20-2.26) for children of African American ethnicity. African American and Mexican American children showed a consistent prevalence of current asthma across age while white children showed an increase in prevalence with age. The 2 highest-risk subgroups identified by the signal detection analysis were composed of children with a parental history of asthma or hay fever who were 10 years or older with a body mass index greater than or equal to the 85th percentile (31.0% current asthma), and children with a parental history who were 10 years or younger and of African American ethnicity (15.6% current asthma). The findings from this analysis show a strong independent association between obesity and current asthma in children and adolescents, and confirm previous reports of a parental history of asthma or hay fever and African American ethnicity as additional important risk factors.

Typescript (photocopy) Thesis (Ph. D.)--Stanford University, 1983. Bibliography: leaves 144-149.

Medicine & Science in Sports & Exercise, 2003

JAMA, 1998

Cardiovascular disease (CVD) risk factors are higher among ethnic minority women than among white... more Cardiovascular disease (CVD) risk factors are higher among ethnic minority women than among white women in the United States. However, because ethnic minority women are disproportionately poor, socioeconomic status (SES) may substantially explain these risk factor differences. To determine whether differences in CVD risk factors by ethnicity could be attributed to differences in SES. Third National Health and Nutrition Examination Survey conducted between 1988 and 1994. Eighty-nine mobile examination centers. A total of 1762 black, 1481 Mexican American, and 2023 white women, aged 25 to 64 years, who completed both the home questionnaire and medical examination. Ethnicity and years of education (SES) in relation to systolic blood pressure, cigarette smoking, body mass index (BMI, a measure of weight in kilograms divided by the square of height in meters), physical inactivity, non-high-density lipoprotein cholesterol (non-HDL-C [the difference between total cholesterol and HDL-C]), and non-insulin-dependent diabetes mellitus. As expected, most CVD risk factors were higher among ethnic minority women than among white women. After adjusting for years of education, highly significant differences in blood pressure, BMI, physical inactivity, and diabetes remained for both black and Mexican American women compared with white women (P<.001). In addition, women of lower SES from each of the 3 ethnic groups had significantly higher prevalences of smoking and physical inactivity and higher levels of BMI and non-HDL-C than women of higher SES (P<.001). These findings provide the greatest evidence to date of higher CVD risk factors among black and Mexican American women than among white women of comparable SES. The striking differences by both ethnicity and SES underscore the critical need to improve screening, early detection, and treatment of CVD-related conditions for black and Mexican American women, as well as for women of lower SES in all ethnic groups.

Cancer Epidemiology Biomarkers & Prevention, 2008

BACKGROUND-Discrimination has been shown as a major causal factor in health disparities, yet litt... more BACKGROUND-Discrimination has been shown as a major causal factor in health disparities, yet little is known about the relationship between perceived medical discrimination (vs. general discrimination outside medical settings) and cancer screening behaviors. We examined whether perceived medical discrimination is associated with lower screening rates for colorectal and breast cancers among racial and ethnic minority adult Californians.

Archives of Pediatrics & Adolescent Medicine, 2002

To provide national estimates of asthma prevalence in African-American, Mexican American and whit... more To provide national estimates of asthma prevalence in African-American, Mexican American and white (non-Latino) children and adolescents using several common definitions; to evaluate familial, sociodemographic, and environmental risk factors that are independently associated with current asthma in children; and to identify subgroups at particular risk for current asthma using 2 complementary data analytic approaches. Cross-sectional study, using the Third National Health and Nutrition Examination Survey, 1988-1994. Eighty-nine mobile examination centers in the United States. Twelve thousand three hundred eighty-eight African American, Mexican American, and white (non-Latino) children and adolescents, aged 2 months through 16 years, selected from a systematic random, population-based, nationally representative sample. Current asthma, defined by caregivers who reported that their child currently had doctor-diagnosed asthma. The overall prevalence of current asthma was 6.7% (95% confidence interval [CI], 5.6-7.8). Odds ratios for current asthma from the multiple regression analysis were 4.00 (95% CI, 2.90-5.52) for children with a parental history of asthma or hay fever, 1.94 (95% CI, 1.09-3.46) for children with body mass index (calculated as weight in kilograms divided by the square of height in meters) greater than or equal to the 85th percentile, and 1.64 (95% CI, 1.20-2.26) for children of African American ethnicity. African American and Mexican American children showed a consistent prevalence of current asthma across age while white children showed an increase in prevalence with age. The 2 highest-risk subgroups identified by the signal detection analysis were composed of children with a parental history of asthma or hay fever who were 10 years or older with a body mass index greater than or equal to the 85th percentile (31.0% current asthma), and children with a parental history who were 10 years or younger and of African American ethnicity (15.6% current asthma). The findings from this analysis show a strong independent association between obesity and current asthma in children and adolescents, and confirm previous reports of a parental history of asthma or hay fever and African American ethnicity as additional important risk factors.

American Journal of Preventive Medicine, 2006

A number of studies have established links between neighborhood social environments and health. I... more A number of studies have established links between neighborhood social environments and health. In a previous study of 8197 adults, death rates for adults with low socioeconomic status (SES) were highest in high-SES neighborhoods, lower in moderate-SES neighborhoods and lowest in low-SES neighborhoods. This study examines whether these findings extend to time to hospitalization. Population-based study of 1686 women and men, aged 25 to 74 at baseline, from 82 neighborhoods in four California cities. Participants were surveyed and medically examined in 1989-1990 and followed through the end of 2002. Neighborhood-level SES was defined by five census variables and divided into three levels. Individual-level SES was defined by household income and educational level and divided into tertiles (nine individual/neighborhood SES groups). There were 627 hospitalizations. The age- and gender-adjusted rates of any hospitalization between 1989-1990 and the end of 2002 for adults with low SES were highest for those living in high-SES neighborhoods (51% compared with 28% to 38% for adults from the other eight individual/neighborhood groups). For these adults, time to hospitalization, as indicated by survival curves, was significantly shorter compared with the other individual/neighborhood groups (p < 0.01, multilevel Cox proportional hazards model). Findings were not explained by baseline differences in individual-level sociodemographic characteristics, health behaviors or risk factors, health status, or proximity to neighborhood goods and services. These findings suggest that factors leading to increased mortality for adults with low SES in high-SES neighborhoods also affect hospitalization.

Cancer Epidemiology Biomarkers & Prevention

Data from a large, population-based case-control study were analyzed to investigate the relations... more Data from a large, population-based case-control study were analyzed to investigate the relationship between prenatal exposure to tobacco smoke and childhood brain tumors (CBTs). A total of 540 CBT patients, diagnosed between 1984 and 1991, were identified from population-based tumor registries in 19 West Coast counties that included Seattle, WA (13 counties), San Francisco, CA (5 counties), and Los Angeles, CA (1 county). Random digit dial was used to select 801 control subjects from the three geographical regions to obtain a case:control ratio of 1:2 in San Francisco and Seattle and 1:1 in Los Angeles. The data first were analyzed separately by geographical site and then were combined with adjustments made for gender, age at the time of diagnosis (or reference date of control subjects), birth year of the index child, and maternal race. No association was found between the risk of CBTs and maternal or paternal smoking before pregnancy and there was no association between CBTs and maternal smoking during pregnancy [odds ratio (OR) = 0.98; 95% confidence interval (CI) = 0.72-1.3]. A slightly increased OR for CBTs was found for paternal smoking during pregnancy in the absence of maternal smoking (OR = 1.2; 95% CI = 0.90-1.5) and for maternal exposure to passive smoke from any source (OR = 1.2; 95% CI = 0.95-1.6). The results of this analysis are consistent with results from several prior epidemiological studies that showed no significant association between CBTs and maternal smoking before or during pregnancy or maternal exposure to passive smoke during pregnancy.

American Journal of Epidemiology

A total of 452 women with cutaneous malignant melanoma and 930 control subjects aged 25-59 years ... more A total of 452 women with cutaneous malignant melanoma and 930 control subjects aged 25-59 years participated in a population-based case-control study carried out in the San Francisco Bay Area between 1981 and 1986. Interviews were conducted in the homes of the women. Questions were asked about various phenotypic characteristics, including eye, hair, and complexion color, presence of freckles, and number of nevi, as well as medical history, history of exposure to sunlight, ability to tan, occupation, use of cigarettes and alcohol, and demographic factors. Histologic type of melanoma was considered in the analysis: 355 (79%) women were diagnosed with superficial spreading melanoma, 61 (13%) had nodular melanoma, 13 (3%) had lentigo maligna melanoma, and 23 (5%) had other melanomas that could not be further classified. For all cutaneous melanoma subjects combined, univariate results related to host factors showed that risk increased with the presence of nevi greater than 5 mm in diame...

Cancer Research

In a case-control study, we explored a potential association between uveal melanoma and reproduct... more In a case-control study, we explored a potential association between uveal melanoma and reproductive factors in women. Responses from telephone interviews of 186 women diagnosed with uveal melanoma were compared with responses of 423 women without this disease. All women resided in 11 U.S. western states. We observed a decreased risk of uveal melanoma for women who had ever been pregnant [relative risk (RR) = 0.60, 95% confidence interval (CI) = 0.37 -0.95], with an increase in this protective effect with more live births after adjustment for age, menopausal status, eye color, and skin sensitivity to the sun (1-2 births, RR = 0.47,95% CI 0.29-0.78; 3-4 births, RR = 0.38, 95% CI = 0.22-0.64; 5 or more births, RR = 0.33, 95% CI = 0.15-0.71). The largest effect was observed between nulliparous and parous women. No other reproductive factors, including use of oral contraceptives or postmenopausal estrogens, were shown to be related to risk for uveal melanoma. We conclude that most repro...

American Journal of Clinical Pathology

The authors reviewed a series of fine-needle aspiration biopsy (FNAB) specimens of the liver to i... more The authors reviewed a series of fine-needle aspiration biopsy (FNAB) specimens of the liver to identify useful cytologic criteria to distinguish hepatocellular carcinoma (HCC) from nonneoplastic liver. Ten cytologic features were examined in this study: high cellularity, acinar pattern, trabecular pattern, hyperchromasia, pleomorphism, irregularly granular chromatin, uniformly prominent nucleoli, multiple nucleoli, increased nuclear/cytoplasmic ratio, and atypical naked hepatocytic nuclei. These features were examined in a series of 82 FNAB specimens from 52 patients with HCC and 30 patients with nonneoplastic lesions. With the use of a step-wise logistic regression analysis, three features were identified as predictive of HCC: increased nuclear/cytoplasmic ratio (P = 0.001), trabecular pattern (P = 0.002), and atypical naked hepatocytic nuclei (P = 0.03). When these three criteria were used, the sensitivity of diagnosing HCC by FNAB was 100%, and the specificity was 87%.

Cancer Research

We conducted a case-control interview study among 1277 subjects (407 patients, 870 controls selec... more We conducted a case-control interview study among 1277 subjects (407 patients, 870 controls selected by using random digit dial) in 11 western United States to determine whether uveal melanoma and cutaneous melanoma shared common risk factors. After adjustment for other factors, the risk of uveal melanoma was increased for those with green, gray, or hazel eyes [relative risk (RR) = 2.5, P less than 0.001] or blue eyes (RR = 2.2, P less than 0.001) when compared to brown. A tendency to sunburn after 0.5 h midday summer sun exposure increased risk for uveal melanoma (burn with tanning RR = 1.5, P = 0.02; burn with little tanning RR = 1.8, P less than 0.001; burn with no tanning RR = 1.7, P = 0.002); as did exposure to UV or black lights (RR = 3.7, P = 0.003); and welding burn, sunburn of the eye, or snow blindness (RR = 7.2, P less than 0.001). An association with uveal melanoma was also noted with an increasing number of large nevi (P = 0.04 for trend), although the individual risk e...

Cancer Research

Forty anal paraffin-embedded tissue specimens from 24 subjects were studied for the presence of h... more Forty anal paraffin-embedded tissue specimens from 24 subjects were studied for the presence of human papillomavirus (HPV) types 6, 11, 16, 18, 31, and 33, herpes simplex virus (HSV), Epstein-Barr virus, and cytomegalovirus DNA by using the polymerase chain reaction. These tissues ranged from histologically normal to invasive squamous cell carcinoma. HPV DNA was detected in the invasive anal cancer tissues of 11 of 13 subjects. HPV types were segregated by histopathological severity, with HPV 16 associated exclusively with high grade anal intraepithelial neoplasia and invasive cancer. HPV types 6 and 11 were associated with condyloma and low grade anal intraepithelial neoplasia. HPV DNA in situ hybridization studies confirmed the presence of HPV DNA in the invasive cancer tissues of 6 of 12 subjects. HPV DNA in these tissues was highly focal and primarily associated with invasive cell nests that demonstrated the greatest degree of squamous differentiation. HSV DNA was detected only ...

American Journal of Epidemiology

Oral contraceptive use and reproductive factors were investigated in a population-based case-cont... more Oral contraceptive use and reproductive factors were investigated in a population-based case-control study of 452 women aged 25-59 years who were diagnosed with cutaneous malignant melanoma during the period 1981-1986 and 930 controls. Ever use of oral contraceptives was reported by 72 percent of melanoma patients and 79 percent of control subjects in this San Francisco Bay Area study, although duration of use was slightly longer for women with superficial spreading melanoma (5.5 years) than for controls (4.3 years). While some subgroups had elevated or reduced odds ratios, no consistent association was observed between cutaneous melanoma risk and oral contraceptive use when use was examined by duration, latency, age at diagnosis, age at first use, and time period of first use. Neither number of live births nor age at birth of the first child was associated with risk for cutaneous melanoma; nor was a history of miscarriage, induced abortion, or endometriosis. No association was obse...

Cancer Epidemiology Biomarkers & Prevention

An analysis of the relationship between the anatomic site of cutaneous melanoma, sun exposure, an... more An analysis of the relationship between the anatomic site of cutaneous melanoma, sun exposure, and phenotype was conducted in 355 women with histologically confirmed superficial-spreading melanoma and in 935 control subjects. The most frequent site for superficial-spreading melanoma was the leg. However, when major sun-related and phenotype risk factors were examined by site, risk ratios were lowest for melanomas that occurred on the leg. A history of frequent sunburns during elementary or high school, increased number of self-assessed large nevi, and blond hair were more strongly associated with melanoma sites other than the leg. Tumors on the trunk were more likely than tumors at other sites to be associated with histological evidence of a preexisting nevus. Results of this work indicate that associations between melanoma phenotypic factors may differ by anatomic site.

American Journal of Epidemiology

A population-based case-control study of cutaneous malignant melanoma (CMM) was conducted in 452 ... more A population-based case-control study of cutaneous malignant melanoma (CMM) was conducted in 452 women with melanoma and 930 control subjects aged 25-59 years in five San Francisco Bay Area counties between 1981 and 1986. Women were interviewed in their homes with regard to history of sunlight exposure and sunburns during different periods in their lives, phenotypic and host characteristics, medical history, occupation, and demographic factors. Data were analyzed by the patients' histologic type of melanoma; 355 women were classified as having superficial spreading melanoma (SSM), 61 had nodular melanoma (NM), 13 had lentigo maligna melanoma, and 23 had other melanomas that could not be further classified upon histologic review by University of California dermatopathologists. Univariate results from analysis of factors related to sun exposure showed that the risk of all histologic types of CMM, SSM, and NM increased with increasing tendency of the subject to sunburn and with his...

American Journal of Epidemiology

To determine risk factors for Ewing's bone sarcoma, the authors interviewed mothers of 43 pat... more To determine risk factors for Ewing's bone sarcoma, the authors interviewed mothers of 43 patients diagnosed between January 1978 and August 1986 and 193 controls in the San Francisco Bay Area, California, regarding medical and occupational history of parents and other factors related to the subjects and their immediate families. Controls were selected by using random digit dial telephone methods. Adjusted relative risk estimates suggest that risks were elevated for children whose fathers were engaged in agricultural occupations during the period from 6 months prior to conception of the subject up to the time of diagnosis for the patients or interview for the controls (relative risk (RR) = 8.8, 95% confidence interval (CI) 1.8-42.7) and for children whose fathers had occupational exposure to herbicides, pesticides, or fertilizers (RR = 6.1, 95% CI 1.7-21.9, p = 0.002). Prior ingestion of poison or an overdose of medication was more common in patients than in controls (RR = 4.4, ...

Annals of internal medicine

To determine the hemopoietic effects of recombinant human granulocyte-macrophage colony-stimulati... more To determine the hemopoietic effects of recombinant human granulocyte-macrophage colony-stimulating factor (GM-CSF) in patients having autologous hemopoietic stem cell transplantation for Hodgkin or non-Hodgkin lymphoma. Placebo or GM-CSF was administered after bone marrow or peripheral blood stem cell transplantation or both in a randomized, double-blind phase III trial by daily intravenous infusion (10 micrograms/kg body weight) until absolute neutrophil counts reached greater than or equal to 1000/mm3 on 3 consecutive days. Bone marrow transplantation unit in a university hospital. Sixty-nine consecutive patients with Hodgkin or non-Hodgkin lymphoma received GM-CSF (36 patients) or placebo (33 patients). Patients who received GM-CSF achieved absolute neutrophil counts greater than or equal to 500/mm3 (median, 12 compared with 16 days, P = 0.02) and absolute neutrophil counts greater than or equal to 1000/mm3 (median, 15 compared with 24 days, P less than 0.001) more quickly than ...

There is a long history of epidemiologists using maps to examine relationships between environmen... more There is a long history of epidemiologists using maps to examine relationships between environments and health. As a result, Geographic Information Systems (GIS) are being increasingly used in epidemiologic research. To raise awareness among epidemiologists and the general public health audience of ways to integrate GIS tools in epidemiologic research, the authors illustrate six tools (defining neighborhood geographic boundaries, determining geographic representation of study participants, determining inclusion/exclusion criteria for analytic variables, calculating distance/density variables for analyses, visualizing change over time in neighborhood physical and demographic environments, and disseminating findings to study communities) that were recently applied in a series of population-based studies of neighborhood environments and cardiovascular disease and mortality. The authors discuss potential applications of each tool and relevant issues to consider. The ultimate aim is to i...