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G A Colditz

Publications and source records attributed to G A Colditz.

At least 325 records · Page 18Linked to original sources
PubMed1995

Development and reproducibility of a food frequency questionnaire to assess diets of older children and adolescents.

OBJECTIVE: To develop a self-administered food frequency questionnaire for older children and adolescents and to demonstrate reproducibility over a 1-year period. DESIGN: The youth/adolescent questionnaire (YAQ) was based on the validated Nurses' Health Study food frequency questionnaire and was developed to reflect the eating habits of this age group. SUBJECTS: The multiethnic sample consisted of 179 youths (ages 9 to 18 years) who completed the questionnaire twice, 1 year apart. STATISTICAL ANALYSIS: Pearson correlation coefficients were calculated on nutrient data adjusted in relation to energy intake and on unadjusted food data. RESULTS: Reproducibility for nutrients ranged from .26 for protein and iron to .58 for calcium, and for foods it ranged from .39 for meats to .57 for soda. Mean reproducibility was higher among girls than boys for energy and nutrients and for foods; no consistent pattern was observed for age. CONCLUSION: A self-administered food frequency questionnaire has a reasonable ability to assess the eating habits of older children and adolescents over time.

Adolescent↗
PubMed1995

Relationship between bacille Calmette-Guérin (BCG) strains and the efficacy of BCG vaccine in the prevention of tuberculosis.

Bacille Calmette-Guérin (BCG) vaccination for the prevention of tuberculosis has been used in humans since 1921. Furthermore, for > 60 years it has been possible to separate BCG strains (defined here as a BCG vaccine maintained in a particular laboratory and used in a particular trial or set of trials) on the basis of in vitro and in vivo tests. Investigators have concluded that differences in the BCG strains used in efficacy trials on humans may be responsible for the wide range in levels of protection from tuberculosis reported in those trials. We review the development of the separate strains used in the trials included in a recent meta-analysis and examine data for and against the protective efficacy of different BCG strains. The difficulties in correlating results of in vitro and in vivo tests with protective efficacy in humans are discussed. The limited data available from human studies suggest that the BCG strain used for vaccination is not a significant determinant of the overall efficacy in the prevention of tuberculosis.

BCG Vaccine↗
PubMed1995

Bacille Calmette-Guérin vaccination for the prevention of tuberculosis in health care workers.

For 60 years vaccination with bacille Calmette-Guérin (BCG) has been used for the prevention of tuberculosis in health care workers. In 1988 the U.S. Advisory Committee on Immunization Practices removed the category of health care worker from the list of persons for whom vaccination with BCG should be considered. Nosocomial epidemics of tuberculosis, especially those caused by multidrug-resistant strains, have led to the reconsideration of vaccination with BCG for this population. We review the available studies of the efficacy of BCG vaccine in health care workers. Although the studies had too many methodological flaws to be combined in a quantitative meta-analysis, they suggest that vaccination with BCG is effective in reducing the incidence of tuberculosis among health care workers.

BCG Vaccine↗
PubMed1995

Geographic latitude and the efficacy of bacillus Calmette-Guérin vaccine.

In a meta-analysis of the efficacy of BCG vaccine for preventing tuberculosis, study sites at a greater distance from the equator were associated with a higher efficacy. In a random-effects regression analysis of prospective studies, geographic latitude alone accounted for 41% of the between-study variance. Many factors that vary with latitude may influence the effectiveness of BCG vaccine by modifying the susceptibility of human hosts, the pathogenecity of the organism, or host-agent interactions. These factors include socioeconomic conditions, genetic composition of the population, climate, exposure to sunlight, diet and nutrition, presence of nontuberculous mycobacteria in the environment, completeness of surveillance and follow-up in studies of BCG vaccine, virulence of locally prevalent strains of Mycobacterium tuberculosis, and storage and viability of BCG vaccine. This paper describes the biological plausibility, epidemiologic evidence, and other scientific data bearing on the influence of these factors on the efficacy of BCG vaccine.

Animals↗
PubMed1995

Body height and hip fracture: a cohort study of 90,000 women.

BACKGROUND: Hip fractures are a major public health problem. Recent studies have noted a connection between body height and hip fracture. METHODS: We investigated the relationship between body height and hip fracture using a prospective cohort of over 92,000 American, predominantly white, female nurses who were followed for 10 years, from June 1980 to June 1990. The women, participants in the Nurses Health Study, were aged 35-59 in 1980. RESULTS: Women 5'8" or taller were more than twice as likely as women under 5'2" to sustain a hip fracture, after accounting for age, body mass index, cigarette smoking and alcohol consumption (multivariate relative risk 2.40, 95% confidence interval: 1.43-4.02; P for trend < 0.0001). CONCLUSION: Height appears to be an important independent risk factor for hip fracture among American women. Height should be included as a confounder in studies of hip fracture, and taller, elderly women should be advised to consider preventive measures.

Adult↗
PubMed1995

Prospective study of physical activity and the risk of symptomatic diverticular disease in men.

The relationship between physical activity and risk of symptomatic diverticular disease has not been investigated directly. This association was examined in a prospective cohort of 47,678 American men, 40 to 75 years of age, and free of diagnosed diverticular disease, colon or rectal polyp, ulcerative colitis, and cancer before 1988. During four years of follow up, 382 newly diagnosed cases of symptomatic diverticular disease were documented. After adjustment for age, energy adjusted dietary fibre, and energy adjusted total fat, overall physical activity was inversely associated with the risk of symptomatic diverticular disease (for highest versus lowest extremes, relative risk (RR) = 0.63 (95% confidence interval (CI) 0.45, 0.88). Most of the inverse association was attributable to vigorous activity, for extreme categories RR = 0.60 (95% CI 0.41, 0.87). For activity that was not vigorous the RR was 0.93 (95% CI 0.67, 1.69). Several specific activities were inversely associated with the risk of diverticular disease, but jogging and running combined was the only individual activity that was statistically significant (p for trend = 0.03). For men in the lowest quintile for dietary fibre intake and total physical activity (compared with those in the opposite extreme), the RR was 2.56 (95% CI 1.36, 4.82). Physical activity, along with a high fibre diet, may be an important factor in the prevention of symptomatic diverticular disease.

Adult↗
PubMed1995

Childhood socioeconomic status and risk of cardiovascular disease in middle aged US women: a prospective study.

OBJECTIVE: To examine prospectively the relationship of childhood socioeconomic status and risk of cardiovascular disease in middle aged women. DESIGN: A prospective cohort of women with 14 years follow up data (1976-90). SUBJECTS: A total of 117,006 registered female nurses aged 30 to 55 years in 1976 and free of diagnosed coronary heart disease, stroke, and cancer at baseline. MAIN OUTCOME MEASURES: Incident fatal coronary heart disease, non-fatal myocardial infarction, and stroke (fatal and non-fatal). RESULTS: Low socioeconomic status in childhood was associated with a modestly increased risk of incident non-fatal myocardial infarction and total cardiovascular disease in adulthood. Compared with middle aged women from white collar childhood backgrounds, the age adjusted risk of total cardiovascular disease for women from blue collar backgrounds was 1.13 (95% CI 1.02, 1.24) and that of non-fatal myocardial infarction was 1.23 (95% CI 1.06, 1.42). No significant increase in risk was observed for stroke or fatal coronary heart disease. Adjustment for differences in family and personal past medical history, medication use, exercise, alcohol intake, diet, birth weight, being breastfed in infancy, and adult socioeconomic circumstance somewhat attenuated the increased risks observed for women from blue collar childhood socioeconomic backgrounds. In multivariate analysis, women whose fathers had been manual labourers had the highest relative risk of total coronary heart disease (RR = 1.53; 95% CI 1.09, 2.16) and non-fatal myocardial infarction (RR = 1.67; 95% CI 1.11, 2.53) when compared with women whose fathers had been employed in the professions. CONCLUSION: In this group lower childhood socioeconomic status was associated with a small but significant increase in the risk of total coronary heart disease as well as non-fatal myocardial infarction. For women from the most socioeconomically disadvantaged childhood backgrounds, the association is not explained by differences in a large number of cardiovascular risk factors, by differences in adult socioeconomic status, or by differences in indices of nutrition during gestation or infancy.

Adult↗
PubMed1995

The validity of recalled weight among younger women.

METHOD: The authors compared recalled weight at age 18 and self-reported current height among 118 participants in the Nurses' Health Study II cohort, aged 25-42 years in 1989, with records from physical examinations conducted at college or nursing school entrance. RESULTS: The correlation between recalled and measured past weight was 0.87 and between reported current height and measured past height was 0.94. Mean body mass index (BMI) values were 21.6 kg/m2 for BMI calculated using recalled weight and 22.1 kg/m2 using weight from medical records; the correlation was 0.84. Participants slightly under-reported weight at age 18 (mean difference = 1.4 kg). CONCLUSION: The validity of recalled weight at 18 years of age and self-reported height as an estimate of height at age 18 appears to be high among women in this cohort.

Adult↗
PubMed1995

Cancer prevention strategies for the future: risk identification and preventive intervention.

The knowledge base may be advanced by concentrating on primary prevention of cancer, which in turn will inform the development of effective and efficient intervention strategies for prevention that may substantially reduce cancer incidence. Several priority areas have been identified, and with new multidisciplinary approaches spanning the biological, epidemiological, social, behavioral, and economic sciences, new initiatives in primary cancer prevention may lead the way toward reducing cancer mortality through primary prevention.

Breast Neoplasms↗
PubMed1995

The efficacy of bacillus Calmette-Guérin vaccination of newborns and infants in the prevention of tuberculosis: meta-analyses of the published literature.

OBJECTIVE: To quantify the efficacy of vaccination of infants with bacillus Calmette-Guérin (BCG) against tuberculosis. DATA SOURCES: MEDLINE with index terms BCG vaccine, tuberculosis, and human; lists of all known studies provided by experts at the Centers for Disease Control and Prevention, the World Health Organization, and other organizations. STUDY SELECTION: A total of 1264 articles and abstracts were reviewed for details on BCG vaccination, the availability of concurrent vaccinated and unvaccinated groups, and a tuberculosis outcome. Seventy articles were reviewed in depth for method of vaccine allocation used to create comparable groups, age at vaccination of study participants, comparability of surveillance and follow-up of recipient and concurrent control groups in trials, an appropriately defined control group in case-control studies, and outcome measures (tuberculosis cases and/or deaths). Five prospective trials and eleven case-control studies of vaccination during infancy were included in the present analyses. DATA EXTRACTION: We recorded study design, age range of study population, number of patients enrolled, efficacy of vaccine, location of the study, and a series of items to assess the potential for bias in study design, follow-up, and diagnosis. We extracted or computed vaccine efficacy by years since vaccination wherever possible. At least two readers independently extracted data and evaluated data validity. DATA SYNTHESIS: The relative risk (RR) or odds ratio (OR) for tuberculosis in vaccinated versus unvaccinated infants was the measure of vaccine efficacy analyzed. A random-effects method estimated a weighted average RR or OR from data extracted from the trials and case-control studies. The protective effect was then computed by 1-RR or 1-OR. Overall, the protective effect of vaccination against cases of tuberculosis was 0.74 (95% confidence interval [95% CI], 0.62 to 0.83) when estimated from four randomized controlled trials, and 0.52 (95% CI, 0.38 to 0.64) when estimated from nine case-control studies. Five trials reporting deaths from tuberculosis showed a BCG protective effect of 0.65 (95% CI, 0.12 to 0.86), five studies reporting on meningitis showed a protective effect of 0.64 (95% CI, 0.30 to 0.82), and three studies of disseminated tuberculosis showed a protective effect of 0.78 (95% CI, 0.58 to 0.88). Three case-control studies included separate results for laboratory-confirmed cases of tuberculosis. These studies documented a protective effect of 0.83 (95% CI, 0.58 to 0.93). In a random-effects regression model of the nine case-control studies, study validity score explained 15% of the heterogeneity among study-estimated protective effects, suggesting that better studies reported greater efficacy. Three trials and six case-control studies provided some age-specific information that allowed us to examine the duration of BCG efficacy. Most of this evidence suggested that BCG efficacy may persist through 10 years after infant vaccination. CONCLUSION: BCG vaccination of newborns and infants significantly reduces the risk of tuberculosis--by over 50%, on average. Protection has been observed across many populations, study designs, and forms of tuberculosis. Rates of protection against cases that are confirmed by laboratory tests, reflecting reduced error in disease classification and consequently more accurate estimates of BCG efficacy, are highest at 83%.

BCG Vaccine↗
PubMed1995

Relation of body fat distribution to reproductive factors in pre- and postmenopausal women.

The cross-sectional relations of several reproductive characteristics with self-reported waist-to-hip circumference ratio were evaluated in 44,487 pre- and postmenopausal women 40 to 65 years of age who were free of cancer, cardiovascular disease, and diabetes. All results were adjusted for age, body mass index, cigarette smoking, physical activity, and alcohol intake. Current use of postmenopausal hormones was associated with a significantly lower waist-to-hip ratio than either past or never use independent of type of menopause (0.778 versus 0.784, p = 0.0001 and 0.787, p = 0.0001, respectively), although associations with type (unopposed estrogens versus combined estrogen and progesterone) and duration of hormone therapy were not noted. Waist-to-hip ratio did not differ between pre- and postmenopausal women, but demonstrated weak positive associations with age at menarche, parity, and age at first birth, and a weak inverse association with past duration of breast-feeding. These data confirm relations of several reproductive factors and use of hormone replacement therapy with body fat distribution. Epidemiologic studies relating body fat distribution to disease outcomes in women should consider these factors as potential confounders.

Adipose Tissue↗
PubMed1994

A prospective study of family history and the risk of colorectal cancer.

BACKGROUND: A family history of colorectal cancer is recognized as a risk factor for the disease. However, as a result of the retrospective design of prior studies, the strength of this association is uncertain, particularly as it is influenced by characteristics of the person at risk and the affected family members. METHODS: We conducted a prospective study of 32,085 men and 87,031 women who had not previously been examined by colonoscopy or sigmoidoscopy and who provided data on first-degree relatives with colorectal cancer, diet, and other risk factors for the disease. During the follow-up period, colorectal cancer was diagnosed in 148 men and 315 women. RESULTS: The age-adjusted relative risk of colorectal cancer for men and women with affected first-degree relatives, as compared with those without a family history of the disease, was 1.72 (95 percent confidence interval, 1.34 to 2.19). The relative risk among study participants with two or more affected first-degree relatives was 2.75 (95 percent confidence interval, 1.34 to 5.63). For participants under the age of 45 years who had one or more affected first-degree relatives, the relative risk was 5.37 (95 percent confidence interval, 1.98 to 14.6), and the risk decreased with increasing age (P for trend, < 0.001). CONCLUSIONS: A family history of colorectal cancer is associated with an increased risk of the disease, especially among younger people.

Adult↗
PubMed1994

Obesity and benign prostatic hyperplasia.

Abdominal obesity increases the estrogen-to-androgen ratio and may increase sympathetic nervous activity, both hypothesized to influence the development of benign prostatic hyperplasia and the severity of urinary obstructive symptoms. In 1986 and 1987, men aged 40-75 years who were participants in the Health Professionals Follow-up Study and who were without prior diagnosis of cancer or prostatectomy provided data on weight, height, and waist and hip circumferences. The men were followed for incidence of prostatectomy for benign prostatic hyperplasia up to January 1992. In addition, the frequency and severity of symptoms of urinary obstruction were assessed among respondents to a questionnaire in 1992. Among 25,892 men who provided complete information for both surgery and symptoms, 837 men had surgery for benign prostatic hyperplasia, and 2,581 of those without surgery reported frequent urinary symptoms. After adjustment for age, smoking, and body mass index, abdominal obesity was related to prostatectomy (odds ratio (OR) = 2.38, 95% confidence interval (CI) 1.42-3.99, for those with a waist circumference > or = 43 inches (109 cm) relative to those with a waist circumference < 35 inches (89 cm); p trend < 0.0001) and with frequent urinary symptoms among those without prostatectomy (OR = 2.00, 95% CI 1.47-2.72; p < 0.0001). Body mass index, hip circumference, and waist-to-hip ratio were not associated with benign prostatic hyperplasia independently of waist circumference. These results suggest that abdominal obesity in men may increase the frequency and severity of urinary obstructive symptoms and may increase the likelihood that such obese men will undergo a prostatectomy.

Anthropometry↗
PubMed1994

A prospective study of permanent hair dye use and hematopoietic cancer.

BACKGROUND: Use of permanent hair dye has been suggested as a risk factor for several types of cancer, although epidemiologic data have not generally supported this hypothesis. Retrospective studies have reported a possible association between hair dyes and hematopoietic cancers. PURPOSE: Our purpose was to investigate if permanent hair dye was associated with risks of incident lymphoma, leukemia, and multiple myeloma in the Nurses' Health Study, a prospective cohort study of 99,067 women aged 30-55 years in 1976. METHODS: Questionnaires regarding medical history and other health-related variables were sent to Nurses' Health Study participants every 2 years from 1976 to 1990. The follow-up for mortality in this cohort exceeds 98%. We identified 244 newly diagnosed cases of hematopoietic cancers, confirmed by pathology reports. Permanent hair dye use was ascertained over four cycles of questionnaires from 1976-1982; status of hair dye use established in 1982 was then used for the remainder of the follow-up time (through 1990). Age-specific incidence rates were calculated and used to compute relative risks (RRs) with 95% confidence intervals (CIs). RESULTS: We found no evidence of a positive association between ever use of permanent hair dye and all hematopoietic cancers (age-adjusted RR = 0.9; 95% CI = 0.7-1.2) or specific types (Hodgkin's lymphoma [RR = 0.9; 95% CI = 0.4-2.1], non-Hodgkin's lymphoma [RR = 1.1; 95% CI = 0.8-1.6], multiple myeloma [RR = 0.4; 95% CI = 0.2-0.9], chronic lymphocytic leukemia [RR = 0.6; 95% CI = 0.3-1.5], and other leukemias [RR = 0.8; 95% CI = 0.3-1.9]). Further examination of age at first use, duration, frequency, and time since first use and risk of all hematopoietic cancers or non-Hodgkin's lymphoma (the largest diagnostic group), indicated no material associations. CONCLUSION: In this prospective cohort study, permanent hair dye use is not adversely related to risks of hematopoietic cancers.

Adult↗
PubMed1994

Aspirin use and the risk for colorectal cancer and adenoma in male health professionals.

OBJECTIVE: To determine whether regular use of aspirin decreases the risk for colorectal cancer. DESIGN: Prospective cohort study. SETTING: Male health professionals throughout the United States. PATIENTS: 47,900 male respondents to a mailed questionnaire in 1986, who were 40 to 75 years of age. MEASUREMENTS: Questionnaires in 1986, 1988, and 1990 about use of aspirin and other variables including occurrence of cancer. RESULTS: 251 new patients were diagnosed with colorectal cancer during the study period. Regular users of aspirin (> or = 2 times per week) in 1986 had a lower risk for total colorectal cancer (relative risk [RR] = 0.68; 95% CI, 0.52 to 0.92) and advanced (metastatic and fatal) colorectal cancer (RR = 0.51; CI, 0.32 to 0.84) after controlling for age; history of polyp; previous endoscopy; parental history of colorectal cancer; smoking; body mass; physical activity; and intakes of red meat, vitamin E, and alcohol. The incremental association was greater among men who reported regular use of aspirin consistently on subsequent questionnaires. The total number of colorectal adenomas discovered among aspirin users was lower with or without overt or occult fecal blood. Thus, earlier diagnosis and treatment of adenomas did not account for the inverse association between aspirin and cancer. CONCLUSIONS: These results support laboratory, clinical, and other epidemiologic evidence that regular use of aspirin is associated with a decreased risk for colorectal cancer.

Adenoma↗
PubMed1994

Oral contraceptive use and mortality during 12 years of follow-up: the Nurses' Health Study.

OBJECTIVE: To examine prospectively the risk for mortality among women who had ever used oral contraceptives compared with those who had never used oral contraceptives. DESIGN: Prospective cohort study. SETTING: Nurses' Health Study. PARTICIPANTS: 166,755 women aged 30 to 55 years in 1976, followed through 1988 (1.3 million person-years of follow-up). RESULTS: On the basis of 2879 deaths, we found no overall difference in mortality among women who had ever used oral contraceptives compared with women who had never used oral contraceptives; the relative risk for ever-users, adjusted for age, body mass index, and cigarette smoking was 0.93 (95% CI, 0.85 to 1.01). We observed no trend in risk for total mortality with increasing duration of past use of oral contraceptives. After adjusting for age, body mass index, and cigarette smoking, women who had used oral contraceptives for 10 or more years had a relative risk of 1.06 (CI, 0.83 to 1.35). CONCLUSION: Use of oral contraceptives is safe; no evidence from this study indicates that long durations of oral contraceptive use adversely affect long-term risk for mortality.

Adult↗