Dutch food bank recipients have poorer dietary intakes than the general and low-socioeconomic status Dutch adult population.

PURPOSE: Food-assistance program users are a specific group of nutritional concern, as they are often food insufficient and have poorer diet quality compared to non-food-assistance program users. The aim of our study was to assess dietary intake of Dutch food bank recipients (n = 167) and to compare this with dietary intake of a representative sample of the general population (Dutch National Food Consumption Survey (DNFCS-all): n = 1933), including a low-socioeconomic status (SES) sample (DNFCS-low SES: n = 312), using data from the DNFCS 2007-2010. METHODS: In this cross-sectional study, 12 food banks throughout The Netherlands participated. Food bank recipients' characteristics were assessed with a self-administered questionnaire. Dietary intake data were collected through three 24-h recalls. Habitual dietary intake (mean, percentiles, and 95% CI) was estimated for all samples. Differences between samples were determined by comparing the 95% CIs. RESULTS: Mean age of the study population (62.9% female) was 48.6 years (SD:10.1). Mean energy intake was 1986 (95% CI 1830-2089) kcal. The majority of the Dutch food bank recipients had lower intakes than dietary reference intakes for dietary fiber, fruit, vegetables, and fish (range 86.6-99.3%), and a higher intake for saturated fat [88.1% (95% CI 84.1-98.9)]. Furthermore, mean intakes of energy, fiber, fruit, and vegetables were significantly lower in Dutch food bank recipients than in the DNFCS-all and the DNFCS-low-SES [e.g., daily mean fruit intake (g) food bank recipients 62.8 (95% CI 45.5-76.5), DNFCS-all 105.8 (95% CI 105.4-117.9), and DNFCS-low-SES 85.1 (95% CI 78.7-100.2)]. Fish intake was significantly lower compared with the DNFCS-all, but not compared with the DNFCS-low-SES. CONCLUSIONS: Dutch food bank recipients, who largely rely on the content of food parcels, are not able to meet the nutritional guidelines for a healthy diet, and their dietary intake is poorer than the general as well as the low-SES sample of the Dutch adult population. More research is needed on how to improve the dietary intake of this vulnerable population subgroup, by, e.g., revising the content of the food parcels, and to develop effective intervention activities.

Seasonal patterns in time series of pertussis.

To gain insight into pertussis disease dynamics, we studied age-specific long-term periodicity and seasonality of pertussis in The Netherlands. Hierarchical time-series models were used to analyse the monthly reported pertussis incidence in January 1996-June 2006 by age group. The incidence of pertussis showed a slightly increasing long-term trend with highest incidence rates seen in 1996, 1999, 2001 and 2004. For all age groups the annual peak incidence was found in August, except for the 13-18 years age group where the peak occurred in November. Monthly trends in adults showed high correlation with trends in age groups 0-4 years (0.94) and 5-12 years (0.92). We found no evidence for a relationship between annual rises in pertussis and the opening of schools. Concurrent annual fluctuations of pertussis incidence in adults and infants suggest frequent transmission within and between these age groups. Studying trends offers insight into transmission dynamics and may facilitate decisions on future vaccination strategies.

Optimization of a monitoring network for sulfur dioxide.

In this study, we develop and apply a methodology to reduce an existing monitoring network to find an optimal configuration of a smaller network. We use a criterion based on locally weighted regression with two different weight functions. The methodology is applied to the Dutch national SO2 network and offers the possibility to include different politically relevant options in the model by weight criteria. Because full enumeration of all monitoring networks is impossible, a combinatorial search algorithm is applied to find a (sub)optimal solution. If different (optimal) monitoring networks result from different criteria, then the best can be selected.

Gaussian Quadrature is an efficient method for the back-transformation in estimating the usual intake distribution when assessing dietary exposure.

In dietary exposure assessment, statistical methods exist for estimating the usual intake distribution from daily intake data. These methods transform the dietary intake data to normal observations, eliminate the within-person variance, and then back-transform the data to the original scale. We propose Gaussian Quadrature (GQ), a numerical integration method, as an efficient way of back-transformation. We compare GQ with six published methods. One method uses a log-transformation, while the other methods, including GQ, use a Box-Cox transformation. This study shows that, for various parameter choices, the methods with a Box-Cox transformation estimate the theoretical usual intake distributions quite well, although one method, a Taylor approximation, is less accurate. Two applications--on folate intake and fruit consumption--confirmed these results. In one extreme case, some methods, including GQ, could not be applied for low percentiles. We solved this problem by modifying GQ. One method is based on the assumption that the daily intakes are log-normally distributed. Even if this condition is not fulfilled, the log-transformation performs well as long as the within-individual variance is small compared to the mean. We conclude that the modified GQ is an efficient, fast and accurate method for estimating the usual intake distribution.

Comparing four methods to estimate usual intake distributions.

BACKGROUND/OBJECTIVES: The aim of this paper was to compare methods to estimate usual intake distributions of nutrients and foods. As 'true' usual intake distributions are not known in practice, the comparison was carried out through a simulation study, as well as empirically, by application to data from the European Food Consumption Validation (EFCOVAL) Study in which two 24-h dietary recalls (24-HDRs) and food frequency data were collected. The methods being compared were the Iowa State University Method (ISU), National Cancer Institute Method (NCI), Multiple Source Method (MSM) and Statistical Program for Age-adjusted Dietary Assessment (SPADE). SUBJECTS/METHODS: Simulation data were constructed with varying numbers of subjects (n), different values for the Box-Cox transformation parameter (λ(BC)) and different values for the ratio of the within- and between-person variance (r(var)). All data were analyzed with the four different methods and the estimated usual mean intake and selected percentiles were obtained. Moreover, the 2-day within-person mean was estimated as an additional 'method'. These five methods were compared in terms of the mean bias, which was calculated as the mean of the differences between the estimated value and the known true value. The application of data from the EFCOVAL Project included calculations of nutrients (that is, protein, potassium, protein density) and foods (that is, vegetables, fruit and fish). RESULTS: Overall, the mean bias of the ISU, NCI, MSM and SPADE Methods was small. However, for all methods, the mean bias and the variation of the bias increased with smaller sample size, higher variance ratios and with more pronounced departures from normality. Serious mean bias (especially in the 95th percentile) was seen using the NCI Method when r(var) = 9, λ(BC) = 0 and n = 1000. The ISU Method and MSM showed a somewhat higher s.d. of the bias compared with NCI and SPADE Methods, indicating a larger method uncertainty. Furthermore, whereas the ISU, NCI and SPADE Methods produced unimodal density functions by definition, MSM produced distributions with 'peaks', when sample size was small, because of the fact that the population's usual intake distribution was based on estimated individual usual intakes. The application to the EFCOVAL data showed that all estimates of the percentiles and mean were within 5% of each other for the three nutrients analyzed. For vegetables, fruit and fish, the differences were larger than that for nutrients, but overall the sample mean was estimated reasonably. CONCLUSIONS: The four methods that were compared seem to provide good estimates of the usual intake distribution of nutrients. Nevertheless, care needs to be taken when a nutrient has a high within-person variation or has a highly skewed distribution, and when the sample size is small. As the methods offer different features, practical reasons may exist to prefer one method over the other.

A rationale for the appropriate amount of inoculum in ready biodegradability tests.

Several screening methods at the so-called ready biodegradability level are suitable to test poorly soluble substances. Typical for these tests is that mineralization is evaluated from monitoring oxygen uptake or carbon dioxide production. Unfortunately, they suffer from a rather low precision in the calculated percentage of mineralization caused by subtracting a too high inoculum control measurement from the response in the test system. Criteria for blank oxygen consumption, due to the metabolic activity of the inoculum, are proposed from which maximum amounts of activated sludge or secondary effluent per litre test medium can be derived to be used as an appropriate inoculum. Both for current and future standardized tests the precision of the method can be kept within acceptable margins. Inoculum material was sampled from 40 communal biological waste water treatment plants. From endogenous respiration rates it was derived that the concentration of secondary effluent in the Closed Bottle Test can be increased up to 50 mL/L but that in respirometry tests inoculated with activated sludge the appropriate concentration is 10 mg/L dry matter or below, depending of the design of the test system.

A quantitative evaluation of monitoring networks for region-specific nitrate reduction policies.

Modern environmental policy implementation in many developed countries is increasingly regionally oriented. Regional governments have undertaken measures designed for the specific needs of the region but, so far, the resulting change in environmental quality has hardly been monitored. This study develops a method for the quantitative evaluation of region-specific environmental policy. Two forms of monitoring are distinguished: monitoring of performance of policy measures and monitoring of environmental quality. This study investigates two regions in the Netherlands where region-specific policy has been implemented. Performance monitoring focused on reduction of nitrate leaching to groundwater. Leaching reductions were calculated with simple models or rules of thumb. Quality monitoring focused on nitrate concentrations under grassland and other land use. An analysis of variance showed significant differences between different soil units. Stratified kriging was applied for spatial interpolation, showing within-unit variability. The current monitoring network could be improved by using a more regular type of grid.