Reproducibility and comparability of a computerized,self‐administered food frequency questionnaire

A self‐administered dietary assessment questionnaire was developed for the microcomputer to identify individuals whose dietary patterns may put them at risk for cancer. It was tested among 50 adult volunteers in a New York school district. The quantitative food frequency portion of the questionnaire (FFQ), administered twice one month apart, was reproducible for calories, fat, percentage of calories from fat, cholesterol, vitamin A, vitamin C, calcium, and dietary fiber (Spearman r = 0.56–0.87). To test for relative validity, individual nutrient intake calculated from each administration of the FFQ was compared with the nutrient intake calculated from seven‐day food records collected one month after the second FFQ administration. Nutrient intake from the first and second FFQ compared with food record nutrient intake yielded a Spearman's correlation coefficient of 0.58 and 0.62, respectively, for percentage of kilocalories from fat. No significant difference in mean intake of percentage of calories from fat was found between the FFQ 1 and FFQ 2 or between the FFQs and the food record. However, there were significant differences between mean food record and FFQ estimates of kilocalories, fat, vitamin A, vitamin C, calcium, and dietary fiber. We concluded that computerized nutrient assessment, which utilizes the subject in data entry, may be suitable for some clinical and educational uses and research studies of intake of fat as a percentage of calories among healthy adults.     

Diet-associated risks of disease and self-reported food consumption: how shall we treat partial nonresponse in a food frequency questionnaire?

Using data from a population-based case-control study on thyroid cancer, we studied two approaches of handling missing answers in a food frequency questionnaire when estimating food consumption and nutrient intakes. We analyzed the dietary reports of 165 cases and 248 control subjects. In the first approach, the omitted food items were considered as "null consumption." In the second approach, the missing answers were replaced with the median frequencies for subjects in the corresponding outcome category actually answering that specific food item. The results showed marginal differences between the two methods. In addition, the null consumption assumption was validated by means of complementary telephone interviews with a subsample of subjects who provided incomplete reports. Overall, the originally omitted answers actually corresponded to very rare consumption for 54.2% of cancer patients and for 54.7% of controls. However, this "true" proportion of null consumption varied greatly between different food items (range 0-96%) and between food groups (range 14-82%). To interpret the omitted self-reports of food consumption as indication of "zero consumption" is quite reasonable when the investigation does not focus on dietary items widely consumed in the source population.     

Development and relative validity of a food frequency questionnaire for the estimation of intake of retinol and β‐carotene

The aim of this study was to develop and validate a semiquantitative food frequency questionnaire to classify individuals according to their intakes of retinol and β‐carotene. Food items for the questionnaire were selected both on the basis of their contribution to total population intake of retinol and β‐carotene and on the proportion of between‐person variation explained, which was as calculated from data of two study populations in the Netherlands. Thus, 15 products containing retinol and 15 products containing β‐carotene were selected. These contributed over 90% to the total intake and explained 99% of the variation of retinol and β‐carotene, respectively. The questionnaire was validated against a dietary history in a population of 82 women (aged 30–49 years). The time elapsed between the two interviews was (on average) 25 days. Spearman rank‐order correlation coefficients comparing the questionnaire with the dietary history were 054, 0.59, and 0.64 for retinol, β‐carotene, and total vitamin A, respectively. The proportion of exact agreement in the two extreme categories of vitamin A intake, based on quintiles, was 56%. The corresponding gross misclassification (from 1 extreme category into the opposite) was 3%. These data indicate that a very short questionnaire can classify subjects into categories according to their vitamin A intake.     

The reproducibility of a food frequency questionnaire among controls participating in a case‐control study on cancer

This study was designed to test the reproducibility of a food frequency questionnaire used in a population‐based case‐control study on diet and pancreatic cancer. Repeat questionnaires covering the same time period were obtained using 63 male and female population controls, 35–79 years of age. For selected food items included in the case‐control study, the attenuation of the odds ratios due to random error was estimated. Using 54 male and female population controls, 35–79 years of age, we conducted a second study to examine the agreement between original and repeat interviews when the time interval between interview and the period of interest was constant.

In the first study, the median correlation coefficient was 0.72 for foods (ranging from 0.36 and 0.59 for subgroups of vegetables to 0.96 for alcoholic beverages) and 0.77 for nutrients (ranging from 0.62 for β‐carotene to 0.85 for energy and 0.91 for ethanol). In the second study, the median correlation coefficient was 0.68 for foods (ranging from 0.28 for eggs to 0.87 for alcoholic beverages) and 0.75 for nutrients (ranging from 0.48 for β‐carotene to 0.76 for energy).

We conclude that for most items the agreement between original and repeat estimates was moderate (r> 0.50) to high (r > 0.70). Moderate agreement was found for 28 of 33 food items (85%) and for all 21 nutrient items (100%) and high agreement for 19 of 33 of food items (56%) and 15 of 21 nutrient items (71 %). In the second study, agreement was somewhat lower but closely paralleled the results of the first study. On average, random error presumably attenuated most of the observed diet‐cancer relationships only moderately; i.e., an observed odds ratio of 1.5 and a correlation coefficient of 0. 70 yield an unattenuated odds ratio of 2.1.     

Healthy Eating Score–7 as a Measure of Diet Quality in a Military Population

ObjectiveIdentify potential revisions to the Healthy Eating Score (HES–5) that improve associations with the Healthy Eating Index (HEI) –2015 total and component scores.MethodsPearson r correlations were determined from soldiers’ (n = 433) survey data, including the HES, proposed additional questions, and the Block Food Frequency Questionnaire.ResultsAdding sugar-sweetened beverages and energy drink questions (HES–7) strengthened the HES and HEI–2015 correlation (HES–5; r = 0.42, n = 433, r² = 0.18, P < 0.001) (HES–7; r = 0.52, r² = 0.27, P < 0.001). The HES components and Block Food Frequency Questionnaire consumption correlations were as follows: quantity of fruit (r = 0.37, r² = 0.14, P < 0.001), vegetables (r = 0.41, r² = 0.17, P < 0.001), whole grains (r = 0.35, r² = 0.12 P < 0.001), dairy (r = 0.34, r² = 0.12, P < 0.001), fish (r = 0.31, r² = 0.10, P < 0.001), and energy drink (r = 0.59, r² = 0.35, P < 0.001).Conclusions and ImplicationsHES–7 had the strongest correlation with HEI–2015. Future studies can explore if including consumption quantity in the HES improves its representation of diet quality.     

Test–retest reliability of a questionnaire measuring perceptions of neighborhood food environment

There is a lack of validated and reliable instruments on perception of the food environment, in particular for rural environments. We estimated the test–retest reliability of a questionnaire assessing perceptions of the food environment. A total of 101 primary food shoppers in South Carolina were interviewed by phone to assess their perceptions of the food environment and presence of different food outlet types in their neighborhood. The survey was repeated approximately one month after the initial administration. The intra-class correlation (ICC) and Phi coefficient are reported as measures of reliability. The majority of questions on perceptions of the neighborhood food environment appear highly reliable (ICCs range from 0.55 to 0.71), including the 3-item scale on healthy food availability (ICC 0.71). Compared to participants in rural areas, those in urban areas demonstrated better reliability for questions on opportunities to purchase fast food and perceived presence of a supercenter. More research is needed to evaluate potential rural–urban differences in reliability.     

Validation of a semi-quantitative adolescent food frequency questionnaire applied at a public school in São Paulo,Brazil

OBJECTIVE: To develop a food frequency questionnaire for adolescents (AFFQ) and demonstrate its relative validity. DESIGN: The final version of the AFFQ was composed of 76 food items previously identified according to their contribution in nutrients and overall importance within the eating habits of this population group. The validation study, which was undertaken during a 6 month period (June to November 1999), was administered to a sample of 79 who answered at least three 24 h dietary recalls (R24 h) applied at intervals of 45 days and one AFFQ at the end of the study. Applying the paired t-test and calculating Pearson correlation coefficients on nutrient data, differences in the mean of nutrients were obtained. Correlation coefficients between the mean energy-adjusted nutrients computed by the two methods were calculated, and correction was made for within-person variability. Agreement was evaluated by distribution of the adolescents according to quartiles of consumption. LOCUS: A public school within the metropolitan region of S?o Paulo city. RESULTS: A high variability in the dietary intake of adolescents was observed, with high rates of variability for cholesterol, retinal and vitamin C. The Pearson correlation coefficients, after being adjusted and corrected for variability, ranged from 0.10 to 0.72 among females and from 0.16 and 0.91 among males. The mean correlation coefficient for the entire group was 0.52. CONCLUSIONS: These results indicate that the AFFQ provides a potentially reliable scale for categorizing individuals by level of past intake of most nutrients, excluding retinol and iron.     

Development of a food frequency questionnaire in a probabilistic sample of adults from Niterói, Rio de Janeiro, Brazil

With the purpose of generating a list of foods for a food-frequency questionnaire, data from 24h dietary recalls on a typical day from a probabilistic sample of 1,724 adults of Niterói, Rio de Janeiro, Brazil, were analyzed. The frequency of food intake, the total intake of energy and macronutrients and the relative contribution of each food item to total energy and macronutrient intake were calculated. The most frequently reported food items (> 50% of adults) were rice, coffee, beans, refined canesugar, and bread. Whole milk was consumed more frequently then skimmed milk or semi-skimmed milk. Beef was consumed by more adults than chicken, pork or fish. Approximately 90% of energy and macronutrients intake was explained by 65 food items. The list of food items generated in the present analysis is similar to those found in other samples of adults from urban areas in Brazil. It may be possible to generate a core list of common foods with addition of regional foods to be used nationally in urban areas of the country.     

Assessing the validity of a food frequency questionnaire among low-income women in São Paulo, southeastern Brazil

This study describes the validity of a food frequency questionnaire (FFQ) in 93 low-income women (20-65 years), participating in a case-control study in S?o Paulo, Brazil. Two FFQ (FFQ1 and FFQ2, 12 months apart) and three 24-hour dietary recalls (24hR) were conducted between 2003 and 2004 to estimate dietary intake during the past year. The Pearson correlation coefficients (crude, energy-adjusted and de-attenuated) were used for comparisons between FFQ and 24hR. The agreement between the methods was further examined by the Bland-Altman analysis. For the assessment of long-term reliability, the energy-adjusted intra-class correlation coefficients were mostly around 0.40, but higher for vitamin A and folate (0.50-0.56). Energy-adjusted, attenuation-corrected Pearson validity correlations between FFQ and DR ranged from 0.30-0.54 for macronutrients to 0.20-0.48 for micronutrients, with higher value for calcium (0.75). There were small proportions of grossly misclassified nutrient intakes, while Bland-Altman plots indicated that the FFQ is accurate in assessing nutrient intake at a group level.     

The influence of education in the validation process of a food frequency questionnaire for adults in Viçosa, Minas Gerais, Brazil

OBJECTIVE: To evaluate the educational influence in the relative validation of a semiquantitative food frequency questionnaire (FFQs) for adults in the city of Vi?osa, Brazil. DESIGN AND SUBJECTS: Four 24-h dietary recalls (reference method) were applied to a sample of 94 adults of both genders, at intervals of 1 month. At the end of the study, an FFQs consisting of 58 food items was also applied. Then, the individuals were divided into two main groups according to their educational level (lower and higher). The dietary data were calculated by the Diet Pro 4.0 software and analyzed according to differences of means or medians and Pearson's correlation coefficients. These coefficients were adjusted by the energy and corrected by the within-person variance for each educational group, considering the extreme quartiles of the data distribution. RESULTS: The intake of energy and nutrients, based on the 24 h dietary recalls, was inferior for the lower educational group (P < 0.05). For the FFQs, just the protein and calcium intakes were statistically different, suggesting interference of the education variable in this assessment. Over estimations in the FFQs were identified in the analyses of means and medians for vitamin C and retinol intakes in the lower education group and for retinol in the higher education one. However, when evaluated by correlation coefficients non-adjusted and adjusted, they were well correlated. On the other hand, lipid (r = 0.34) and calcium (r = 0.13) coefficients of the group with less instruction showed beneath the desirable values, suggesting weak consistence of the estimates provided by the FFQs for these nutrients. Correlation means of r = 0.65 and 0.54 were found for the higher and lower educational groups, respectively. CONCLUSIONS: The results indicate that FFQs showed acceptable performance on evaluating the habitual food consumption for most of the nutrients in the studied population. A tendency for better quantifications in the groups with higher education was observed, inferring its influence in the assessment of the dietary intake.     

Can a food frequency questionnaire be used to capture dietary intake data in a 4 week clinical intervention trial?

Collecting dietary data in the clinical research setting is labour intensive and can be burdensome for study participants. The aim of this study was to assess the agreement between data obtained from 2 different dietary assessment methods, a 74-item semi-quantitative food frequency questionnaire (FFQ) and 3-day weighed food records (WFR) used to estimate dietary intake over the preceding month. One hundred and fifty nine subjects, aged between 31 and 74 years (53 males, 65 females), enrolled in a clinical trial at the Commonwealth Scientific and Industrial Research Organisation, Division of Health Sciences and Nutrition, (CSIRO HSN) Adelaide, Australia. Group mean intakes and individual mean intakes estimated by the two measures were compared. One hundred and eighteen (91%) three-day WFR and their corresponding FFQ were analysed. Pearson correlation coefficients ranged from 0.22 for cholesterol to 0.78 for alcohol (median 0.41). Mean energy and nutrient intakes were within +/- 20% difference. The FFQ gave lower carbohydrate intake estimates, percentage energy from carbohydrate (P <0.001) and dietary fibre (P <0.05) and gave higher percentage energy from saturated fat estimates, poly-unsaturated fatty acids (P <0.001) and mono-unsaturated fatty acids (P <0.05). Subjects were also ranked into quintiles and the quintiles cross-tabulated. The FFQ classified more than two thirds of the subjects within +/-1 quintile difference for all nutrients. We conclude that this FFQ can capture similar information as WFR and may be used for estimation of dietary intakes over a relatively short time in clinical intervention trials.     

Sex- and age-specific trends in mortality from suicide and undetermined death in Germany 1991–2002

Background  

Over the last decade, significant downward linear time trends in suicide mortality were observed in most Western countries. To date, it is not established whether those favourable time trends developed homogeneously for sex and age groups and how they were affected by the number of undetermined deaths.     

Indoor allergen exposure in west and East Germany: a cause for different prevalences of asthma and atopy?

West and East Germans have been living in two different political systems for 40 years. These two populations have become a classic epidemiological example for the hypothesis that lifestyle changes accompanying the industrial and economic development of modern societies are responsible for an increase in the prevalence of atopic diseases. A higher prevalence of atopic sensitization, asthma, and hay fever was found in young West Germans after the unification. It has been hypothesized that this phenomenon was at least partially due to the installation of insulating windows and central heating systems in Western homes, favoring the growth of microorganisms like mites and moulds and increasing indoor allergen exposure. This review summarizes studies that have investigated reservoir concentrations of indoor allergens in public buildings and private homes in East and West Germany. Whereas a higher prevalence of atopic sensitization in West Germans was found for nearly all tested allergens (cat, mite, pollen), allergen exposure was higher only for cat allergens, but probably not for mite and cockroach allergens or moulds. The published data do not support the view that the differences in specific sensitization are caused by differences in the exposure to specific allergens.     

Everyday doings in a nursing home – described by residents and staff

Objective: For many groups of elderly people it is important to be active, which can be hindered by disabilities that come with age. Research has progressed in this area but mostly concerns the elderly living at home. The aim of this study was to examine how residents and staff at a nursing home described the residents’ everyday doings. Methods: A nursing home was selected in which 15 of the residents and six of the staff were interviewed about the residents’ activities during an ordinary day and week. Results: The material was analysed using qualitative content analysis in which two categories emerged: shared doings and individual doings. The shared doings were important for supporting the residents in their social and physical activities, but participation in these was often hampered by reduced functions. The individual doings, where the residents’ own interests can be promoted, were also hampered by their disabilities. Being able to be active and having something to do were emphasized, either continuing with previous activities or participating in shared activities at the nursing home. Conclusions: Receiving care and being forced to adjust to the context at the nursing home had a significant impact on the residents’ daily doings. Most of the residents needed help to be able to continue performing their activities or to find new ones. The social environment consisting of other residents and staff also influenced the residents’ activities.     

Long‐term (24‐year) recall reliability in cancer cases and controls using a 21‐item food frequency questionnaire

We have previously identified dietary patterns among 1,475 male and 780 female normal healthy control subjects in a case‐control study of cancer at various sites. In this paper we examine the presence, among persons exhibiting these dietary patterns, of individual health behaviors that may contribute to risks for cancer. Specifically we examine trimming of separable fat from meats, fats used in cooking and as additions to foods, alcohol consumption, and smoking. Results indicate that men and women differ in possession of these high‐risk behaviors. Women are more likely to trim fat from meat, consume less alcohol, and have lower exposures to smoking. Their dietary patterns are more independent of the fats used. Several eating patterns are positively associated with total fat intake but differ in their associations with high‐risk behaviors. These data suggest that assessing risk associated with dietary patterns sheds more light on disease relationships than studies of single nutrients.     

Inflammatory Potential of Diet and Risk of Ulcerative Colitis in a Case–Control Study from Iran

Diet and inflammation have been suggested to be important risk factors for ulcerative colitis (UC). In this case–control study conducted in Iran, we examined the ability of the dietary inflammatory index (DII) to predict UC. This study included 62 UC cases and 124 controls hospitalized for acute non-neoplastic diseases. The DII was computed based on dietary intake assessed by a previously validated food frequency questionnaire. Multivariable logistic regression models were used to estimate odds ratios (ORs) and the DII was analyzed as both continuous and as tertiles. Energy was adjusted using the residual method. Subjects with higher DII scores (i.e., with a more pro-inflammatory diet) had a higher risk of UC, with the DII being used as both a continuous variable (OR_continuous 1.55, 95% confidence interval (CI) 1.04–2.32; one unit increase corresponding to ≈8% of its range in the current study) and as tertiles (OR_{tertile3vstertile1} 2.58, 95% CI 1.03–6.48, P_trend| = |0.04). These results indicate that a pro-inflammatory diet is associated with increased risk of UC.     

Leisure time sports activity and all-cause mortality in West Germany (1984–1998)

Background Current data and available studies suggest that regular physical activity decreases overall mortality. In Germany corresponding findings are scarce. The aim of this data analysis was to clarify this issue for a German sample in men and women.Methods A total of 3,742 males and 3,445 females aged 30–69, who participated in a baseline questionnaire in 1984–1986, were followed-up to the year 1998.Results During the follow-up period, 300 women and 643 men died. The multivariate rate ratios (RR) for accumulated hours of leisure time sports activities (LTSA) per week and with an LTSA-index based on METs per week with the reference of sedentary lifestyle, showed a clearly protective impact in a dose-response relationship (p for trend <0.05). Similar trends were observed in women and men. More than 2 hours of LTSA per week produced a RR of 0.70 (95% confidence interval [CI]: 0.54–0.91) in men and 0.57 (95% CI: 0.35–0.94) in women. In the group with the highest LTSA-index, the RR was 0.61 (95% CI: 0.44–0.84) in men and 0.46 (95% CI: 0.25–0.85) in women.Conclusion LTSA is inversely associated with all-cause mortality in females and males.     

Low back pain and lumbago–sciatica in nurses and a reference group of clerks: results of a comparative prevalence study in Germany

OBJECTIVES: To gain more conclusive evidence on the question of work-related low-back disorders in German nurses, a comprehensive study with several methodological approaches was performed. METHODS: As part of this project, a cross-sectional study on working conditions and prevalence of low back pain, a sample of 3,332 nurses and 1,720 clerks as reference group was investigated by a questionnaire. In this article, final results referring to a sub-sample of 2,207 nurses and 1,177 clerks who had always worked in their profession, so that we could exclude confounding effects of former occupations, will be presented. Excluding the confounding effects of several covariates by logistic regression, we computed relative risks for different pain symptoms. RESULTS: The data suggest a considerably higher risk of low back pain for nurses than for the reference population of clerks. Results, however, differ markedly when specific pain symptoms are considered. With respect to lumbago-sciatica and sciatica - which have to be regarded as indicators for possible disc herniation - the study group's relative risk is the most elevated (2.88 for point prevalence of lumbago-sciatica/sciatica). Adjusting the results for several confounders and covariates leads to still higher estimations of nurses' relative risk.