Biomedical subjects

A O Coates

Publications and source records attributed to A O Coates.

6 recordsLinked to original sources

PubMed1999

Does nutritionist review of a self-administered food frequency questionnaire improve data quality?

OBJECTIVE: This study sought to evaluate the benefit of utilizing a nutritionist review of a self-administered food frequency questionnaire (FFQ), to determine whether accuracy could be improved beyond that produced by the self-administered questionnaire alone. DESIGN: Participants randomized into a dietary intervention trial completed both a FFQ and a 4-day food record (FR) at baseline before entry into the intervention. The FFQ was self-administered, photocopied and then reviewed by a nutritionist who used additional probes to help complete the questionnaire. Both the versions before nutritionist review and after nutritionist review - were individually compared on specific nutrients to the FR by means, correlations and per cent agreement into quintiles. SETTINGS AND SUBJECTS: Three hundred and twenty-four people, a subset of participants from the Polyp Prevention Trial - a randomized controlled trial examining the effect of a low-fat, high-fibre, high fruit and vegetable dietary pattern on the recurrence of adenomatous polyps - were recruited from clinical centres at the University of Utah, University of Buffalo, Memorial Sloan Kettering Cancer Center in New York and Kaiser Permanente Medical Program in Oakland. RESULTS: Reviewing the FFQ increased correlations with the FR for every nutrient, and per cent agreement into quintiles for all nutrients except calcium. Energy was underestimated in both versions of the FFQ but to a lesser degree in the version with review. CONCLUSIONS: One must further evaluate whether the increases seen with nutritionist review of the FFQ will enhance our ability to predict diet-disease relationships and whether it is cost-effective when participant burden and money spent utilizing trained personnel are considered.

Data Collection↗

PubMed1998

Comparison of the Block and the Willett self-administered semiquantitative food frequency questionnaires with an interviewer-administered dietary history.

The performances of two commonly used diet instruments, the Block and the Willett food frequency questionnaires, were compared with a longer, interviewer-administered diet history. Participants in a case-control study on diet and colon cancer were interviewed between 1990 and 1994 in northern California, Utah, and Minnesota by trained nutritionists using a validated diet history. Two separate subsamples of participants were asked to complete either the Block or the Willett questionnaire exactly 5 days after they completed the original diet history. Data were analyzed separately by subsample comparing either the Block or the Willett questionnaire with the original diet history by using means, correlations, quintile agreement, and odds ratios for the relation between several nutrients and colon cancer. The Block and the Willett questionnaires generally provided lower absolute intake estimates than did the original diet history; however, the Block questionnaire underestimated more than did that by Willett. Both correlations and quintile agreement were slightly better for the Willett questionnaire than for that by Block when compared with the original diet history. In general, point estimates obtained from either the Block or the Willett questionnaire fell within the confidence intervals of the estimates of the odds ratios obtained from the original diet history, and no real difference in significance levels appeared. Although the Block and Willett questionnaires differed slightly from each other and from our original diet history in estimating absolute nutrients and ranking or classifying individuals, they were very similar in their ability to predict disease outcome.

Adult↗

PubMed1998

Drugs and colon cancer.

In a case-control study of colon cancer conducted in three geographic regions of the United States, 1993 case subjects and 2410 control subjects were interviewed. In addition to queries regarding other known or suspected risk factors, subjects were asked about their use of eight drugs or drug groups. Two of these, aspirin and other nonsteroidal anti-inflammatory drugs (NSAIDs), have been inversely associated with risk in other studies. Three others--asthma medications, digitalis preparations, and phenmetrazine--were positively associated and the last three--diazepam, penicillin, and phenformin--were negatively associated with risk of colon cancer in an earlier study that screened pharmaceuticals for possible carcinogenic effects. Reported use of aspirin and NSAIDs were both inversely related to risk with essentially the same odds ratios (0.7, 95% confidence interval 0.6-0.8) for both drugs in both univariate and multivariate analyses controlling for use of each other and for other colon cancer risk factors. Subdivision by age at starting the drug, duration of use, latency interval, sex, race, family history of colon cancer, or proximal versus distal cancer revealed no substantial differences among subgroups for either aspirin or NSAIDs, but reduced risk was associated primarily with recent aspirin use. Phenformin showed a strong positive association but the data concerning this drug appeared to be inaccurate. The other drugs and drug groups showed essentially no association with colon cancer risk.

Journal Article↗

PubMed1998

Body size and the risk of colon cancer in a large case-control study.

OBJECTIVE: To investigate the risks of height, weight and body fat distribution associated with colon cancer in subcategories of gender, age and site in the colon. Interaction with family history of colorectal cancer is also examined. DESIGN: Case-control study of diet, anthropometry and colon cancer risk. SUBJECTS: Nineteen hundred and eighty-three colon cancer cases (age 30-79 y) and 2400 age and gender matched population controls. MEASUREMENTS: Height, weight and waist and hip circumferences were obtained by trained interviewers. Body Mass Index (BMI) and Waist-Hip Ratio (WHR) were calculated. RESULTS: Of all anthropometric measurements examined, only BMI was consistently associated with an increased risk of colon cancer. The test for trend for BMI was significant for men and women overall and for the majority of subgroups examined. In younger persons those with a family history of colorectal cancer had a greater risk of colon cancer associated with BMI (Men odds ratio (OR) = 7.76, 95% confidence interval (CI) 2.60, 23.1; Women OR = 4.85, 95% CI 2.33, 10.12) comparing the third tertile to the first, than those with no family history (Men OR = 1.70, 95% CI 1.25, 2.32; Women OR = 1.53, 95% CI 1.22, 1.92). WHR, after controlling for BMI was not associated with colon cancer in men, and was associated with a slight increase in women (primarily in those with distal tumors). CONCLUSION: This study contributes to mounting evidence that excess weight is associated with an increased risk of colon cancer.

Adult↗

PubMed1998

Differences in fertility associated with caffeinated beverage consumption.

OBJECTIVES: The effect of caffeine consumption on fertility was examined prospectively in 210 women. METHODS: Women reported on caffeinated beverage consumption and pregnancy status monthly. Odds ratios for becoming pregnant were calculated for both high and moderate vs low consumption. RESULTS: No significant association was found for any of the caffeinated beverages except tea. Drinking one-half cup or more of tea daily approximately doubled the odds of conception per cycle. CONCLUSIONS: These data suggest that caffeine may not be the responsible agent for variation in fertility associated with consumption of the beverages examined.

Adult↗

PubMed1997

Performance of a shortened telephone-administered version of a quantitative food frequency questionnaire.

PURPOSE: We evaluated the performance of a telephone-administered food frequency questionnaire in a study of 190 men and women, 30-79 years of age, who participated as controls in a study of colon cancer. METHODS: The telephone version of the questionnaire was modified from a longer food frequency questionnaire originally administered in person to each of the participants. One month later, the telephone questionnaire was administered to a subgroup of 190 participants and readministered to 169 members of the subgroup two weeks later to assess the reproducibility and comparative validity of the instrument. RESULTS: The unadjusted correlation for energy between the original in-person full food frequency questionnaire and the abbreviated telephone version was 0.69. The median energy intake from the telephone version was 17% lower in men and 23% lower in women. The energy and sex-adjusted correlation coefficients for other nutrients ranged from 0.45 for vitamin E to 0.78 for fiber. The intraclass correlation coefficients to measure reproducibility ranged from 0.62 for animal protein to 0.83 for folate. CONCLUSIONS: These data indicate that this brief, telephone-administered questionnaire is reproducible and provides a ranking of nutrient intake comparable to that provided by a full in-person interview.

Adult↗