Showing papers by "Arthur Schatzkin published in 2001"

Design and Serendipity in Establishing a Large Cohort with Wide Dietary Intake Distributions The National Institutes of Health–American Association of Retired Persons Diet and Health Study

Abstract: In 1995-1996, the authors mailed a food frequency questionnaire to 3.5 million American Association of Retired Persons members who were aged 50-69 years and who resided in one of six states or two metropolitan areas with high-quality cancer registries. In establishing a cohort of 567,169 persons (340,148 men and 227,021 women), the authors were fortunate in that a less-than-anticipated baseline response rate (threatening inadequate numbers of respondents in the intake extremes) was offset by both a shifting and a widening of the intake distributions among those who provided satisfactory data. Reported median intakes for the first and fifth intake quintiles, respectively, were 20.4 and 40.1 (men) and 20.1 and 40.0 (women) percent calories from fat, 10.3 and 32.0 (men) and 8.7 and 28.7 (women) g per day of dietary fiber, 3.1 and 11.6 (men) and 2.8 and 11.3 (women) servings per day of fruits and vegetables, and 20.7 and 156.8 (men) and 10.5 and 97.0 (women) g per day of red meat. After 5 years of follow-up, the cohort is expected to yield nearly 4,000 breast cancers, more than 10,000 prostate cancers, more than 4,000 colorectal cancers, and more than 900 pancreatic cancers. The large size and wide intake range of the cohort will provide ample power for examining a number of important diet and cancer hypotheses.

Empirical Evidence of Correlated Biases in Dietary Assessment Instruments and Its Implications

Abstract: Multiple-day food records or 24-hour recalls are currently used as "reference" instruments to calibrate food frequency questionnaires (FFQs) and to adjust findings from nutritional epidemiologic studies for measurement error. The common adjustment is based on the critical requirements that errors in the reference instrument be independent of those in the FFQ and of true intake. When data on urinary nitrogen level, a valid reference biomarker for nitrogen intake, are used, evidence suggests that a dietary report reference instrument does not meet these requirements. In this paper, the authors introduce a new model that includes, for both the FFQ and the dietary report reference instrument, group-specific biases related to true intake and correlated person-specific biases. Data were obtained from a dietary assessment validation study carried out among 160 women at the Dunn Clinical Nutrition Center, Cambridge, United Kingdom, in 1988-1990. Using the biomarker measurements and dietary report measurements from this study, the authors compare the new model with alternative measurement error models proposed in the literature and demonstrate that it provides the best fit to the data. The new model suggests that, for these data, measurement error in the FFQ could lead to a 51% greater attenuation of true nutrient effect and the need for a 2.3 times larger study than would be estimated by the standard approach. The implications of the results for the ability of FFQ-based epidemiologic studies to detect important diet-disease associations are discussed.

A Prospective Study of Diet Quality and Mortality in Women

Abstract: Results There were 2065 deaths due to all causes in the cohort. The RFS was inversely associated with all-cause mortality. Compared with those in the lowest quartile, subjects in the upper quartiles of the RFS had relative risks for all-cause mortality of 0.82 (95% confidence interval [CI], 0.73-0.92) for quartile 2, 0.71 (95% CI, 0.620.81) for quartile 3, and 0.69 (95% CI, 0.61-0.78) for quartile 4 adjusted for education, ethnicity, age, body mass index, smoking status, alcohol use, level of physical activity, menopausal hormone use, and history of disease (x 2 1 for trend=35.64, P,.001

Hormone Replacement Therapy and Colorectal Adenoma Recurrence Among Women in the Polyp Prevention Trial

Abstract: Background Epidemiologic studies have suggested that estrogen may protect against the development of colorectal cancers and adenomatous polyps. We conducted a prospective study to evaluate the association between hormone replacement therapy (HRT) and adenoma recurrence among perimenopausal and postmenopausal women participating in the Polyp Prevention Trial, a randomized dietary intervention study of individuals with colorectal adenomas. Methods We used a questionnaire and interviews to collect detailed information, at baseline and at each of four annual study visits, from 620 women regarding hormone use, menopausal status, diet, alcohol consumption, and other risk factors. Adenoma recurrence was ascertained by complete colonoscopy at baseline and after 1 and 4 years. Logistic regression models were used to evaluate the association between hormone use and adenoma recurrence after adjusting for intervention group and for age and body mass index at baseline. All statistical tests were two-sided. Results Adenomas recurred in 200 women. There was no overall association between adenoma recurrence and either overall hormone use (odds ratio [OR] = 1.01; 95% confidence interval [CI] = 0.70 to 1.45), combined estrogen and progestin use (OR = 0.94; 95% CI = 0.57 to 1.56), or unopposed estrogen use (OR = 1.04; 95% CI = 0.68 to 1.59). HRT use was associated with a reduction in risk for recurrence of distal adenomas (OR = 0.56; 95% CI = 0.32 to 1.00) and a statistically nonsignificant increase in risk for recurrence of proximal adenomas (OR = 1.39; 95% CI = 0.85 to 2.26). We observed a statistically significant interaction between the HRT-adenoma recurrence association and age (P =.02). HRT was associated with a 40% reduced risk of adenoma recurrence among women older than 62 years (OR = 0.58; 95% CI = 0.35 to 0.97) but with an increased risk among women younger than 62 years (OR = 1.99; 95% CI = 1.11 to 3.55). Conclusions HRT was not associated with a reduced risk for overall adenoma recurrence in this trial cohort, although there was a suggestion of an age interaction. The effect of age on the association needs to be confirmed in other adenoma recurrence trials.

Bone Mass and the Risk of Colon Cancer among Postmenopausal Women The Framingham Study

Abstract: Although postmenopausal estrogen use has been associated with a lower risk of colon cancer in women, some studies do not confirm such findings. No known study has examined the effect of cumulative estrogen exposure on colon cancer risk. Bone mass has been proposed as a marker of cumulative exposure to endogenous and exogenous estrogens. By using data on 1,394 Massachusetts women in the Framingham Study who underwent hand radiography in 1967-1970, the authors examined the association between bone mass (from relative areas of the second metacarpal) and colon cancer incidence. Over 27 years of follow-up, 44 incident colon cancer cases occurred. Colon cancer incidence decreased from 2.19 per 1,000 person-years among the women in the lowest age-specific tertile of bone mass to 1.59 and 1.08 among women in the middle and the highest tertiles, respectively. After adjustment for age and other potential confounding factors, the rate ratios of colon cancer were 1.0, 0.7 (95% confidence interval: 0.3, 1.3), and 0.4 (95% confidence interval: 0.2, 0.9) from the lowest to the highest tertile (p for trend = 0.033). No association was found between bone mass and rectal cancer. The findings suggest that women with higher bone mass, perhaps reflecting greater cumulative estrogen exposure, have a decreased risk of colon cancer.