Questionnaires frequency analyses

In most studies, phytoestrogen intake has been estimated by direct methods that evaluate food intake either by recall (food-frequency questionnaires -FFQs) or by record (food diary), and subsequently by composition databases based on information of this kind. Food-frequency questionnaires are widely administered to subjects involved in epidemiological studies. Their validity and reproducibility is considered sufficient when statistically correlated to data obtained from dietary records (a properly-completed and comprehensive food diary) and from analysis of blood and urine samples (Kirk et ah, 1999 Huang et al, 2000 Yamamoto et al, 2001 Verkasalo et al, 2001). FFQs can be repeated several times a year and may be administered to large populations. Such an approach provides an easy and low-cost method of assessing the... 

There have been several attempts to estimate the quantities of PPT consumed, either by using diet diaries or food frequency questionnaires and data on the typical composition of individual commodities h -SQ- Cio8-ii3 j. analysis." " In comparison with the com-... 

Dermal/Ocular Effects. Dermatitis was found by a questionnaire survey to occur in persons living in homes treated with chlordane, with greater frequency than in a reference population (Menconi et al. 1988). The effects, however, cannot be attributed to chlordane alone, because aldrin and heptachlor were included in the analysis for chlordane in the residents indoor air. 

Shannon et al. (1996) is an example of a study limited in both of these ways. It doesn t have any variables on employees involvement with the company s financial returns, and it doesn t present the results of the analysis in a multivariate ftamewoik. The researchers examine a matched sample of questionnaires sent to firms in Ontario with data on those firms lost-time frequency rates (equivalent to the analysis of claim frequency given below). Survey questionnaires include responses from both workers and management. The paper discusses only univariate statistical analyses that compare various workplace practices to whether a firm has a low, medium, or high claim frequency. A multivariate regression analysis is mentioned but not reported on in the paper. 

Rothenberg, E., 1994, Validation of the food frequency questionnaire with the 4-day record method and analysis of 24-h urinary nitrogen. Ear. J. Clin. Nutr. 48 725-735. 

Research has shown a correlation between saturated fat intake and cancer risk. A reeent prospeetive eohort study performed by the European Prospective Investigation into Cancer projeet fonnd no association between breast cancer and satnrated fat intake measnred by a food-frequency questionnaire, but when nsing a food diary, a daily intake of 35 g of saturated fat doubles the risk of breast cancer in comparison to women who had a daily intake of 10 g or less. A greater intake of satnrated fat may increase the risk of esophageal adenocarcinoma and distal stomach cancCT. In addition, a meta-analysis of the association between dietary fat intake and breast cancer found significant summary relative risks for saturated fat. ... 

The qualitative evaluation of the questionnaires was performed taking the number of positive and negative comments about the CMS and frequency calculations into account. For the analysis of the distance estimation, a paired t— test was calculated. Analysis of Particularities Mentioned by the Subjects Positive comments... 

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