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Randomized response (RR) is a well-known interview technique designed to eliminate evasive response bias that arises from asking sensitive questions. The most frequently asked questions in RR are either whether respondents were "ever" carriers of the sensitive characteristic, or whether they were carriers in a recent period, for instance, "last year". The present paper proposes a design in which both questions are asked, and derives a multinomial model for the joint analysis of these two questions. Compared to the separate analyses with the binomial model, the model makes a useful distinction between last year and former carriers of the sensitive characteristic, it is more efficient in estimating the prevalence of last year carriers, and it has a degree of freedom that allows for a goodness-of-fit test. Furthermore, it is easily extended to a multinomial logistic regression model to investigate the effects of covariates on the prevalence estimates. These benefits are illustrated in two studies on the use of anabolic androgenic steroids in the Netherlands, one using Kuk and one using both the Kuk and forced response. A salient result of our analyses is that the multinomial model provided ample evidence of response biases in the forced response condition. [ABSTRACT FROM AUTHOR]

A longitudinal study was conducted among bereaved parents to examine the relationship between the circumstances surrounding the death of their child and psychological adjustment. Two hundred nineteen couples participated at 6, 13, and 20 months post-loss. Examination was made of two categories of factors: those that were determined by the particular death circumstances (e.g., whether the parent was present at the death) versus those over which parents themselves could have influence (e.g., choice of cremation or burial). Results indicated that some but not all factors were related to adjustment over time. Importantly, the feeling of having said goodbye to the child and presenting the body for viewing at home were associated with lower levels of the parents' grief. Implications for supporting bereaved parents are discussed. (Contains 4 tables and 2 footnotes.)

Randomized response (RR) is a well-known method for measuring sensitive behavior. Yet this method is not often applied because: (i) of its lower efficiency and the resulting need for larger sample sizes which make applications of RR costly; (ii) despite its privacy-protection mechanism the RR design may not be followed by every respondent; and (iii) the incorrect belief that RR yields estimates only of aggregate-level behavior but that these estimates cannot be linked to individual-level covariates. This paper addresses the efficiency problem by applying item randomized-response (IRR) models for the analysis of multivariate RR data. In these models, a person parameter is estimated based on multiple measures of a sensitive behavior under study which allow for more powerful analyses of individual differences than available from univariate RR data. Response behavior that does not follow the RR design is approached by introducing mixture components in the IRR models with one component consisting of respondents who answer truthfully and another component consisting of respondents who do not provide truthful responses. An analysis of data from two large-scale Dutch surveys conducted among recipients of invalidity insurance benefits shows that the willingness of a respondent to answer truthfully is related to the educational level of the respondents and the perceived clarity of the instructions. A person is more willing to comply when the expected benefits of noncompliance are minor and social control is strong.

Asked Dutch university and Russian high school students to sort statements in terms of moral sophistication to investigate hierarchical stage structure of moral stages. Found that sorting statements representative of stages below one's own was straightforward; sorting statements above one's stage was difficult, suggesting that reflective abstraction can be used to operationalize and measure hierarchical nature of moral development. (Author/KB)

Given the rapid rate at which text data are being digitally gathered in the medical domain, there is growing need for automated tools that can analyze clinical notes and classify their sentences in electronic health records (EHRs). This study uses EHR texts to detect patients' disease history from clinical sentences. However, in EHRs, sentences are less topic-focused and shorter than that in general domain, which leads to the sparsity of co-occurrence patterns and the lack of semantic features. To tackle this challenge, current approaches for clinical sentence classification are dependent on external information to improve classification performance. However, this is implausible owing to a lack of universal medical dictionaries. This study proposes the ETM (enrichment by topic modeling) algorithm, based on latent Dirichlet allocation, to smoothen the semantic representations of short sentences. The ETM enriches text representation by incorporating probability distributions generated by an unsupervised algorithm into it. It considers the length of the original texts to enhance representation by using an internal knowledge acquisition procedure. When it comes to clinical predictive modeling, interpretability improves the acceptance of the model. Thus, for clinical sentence classification, the ETM approach employs an initial TFiDF (term frequency inverse document frequency) representation, where we use the support vector machine and neural network algorithms for the classification task. We conducted three sets of experiments on a data set consisting of clinical cardiovascular notes from the Netherlands to test the sentence classification performance of the proposed method in comparison with prevalent approaches. The results show that the proposed ETM approach outperformed state-of-the-art baselines. [ABSTRACT FROM AUTHOR]

For zero-truncated count data, as they typically arise in capture-recapture modelling, the nonparametric lower bound estimator of Chao is a frequently used estimator of population size. It is a simple, nonparametric estimator involving only counts of one and counts of two. The estimator is asymptotically unbiased if the count distribution is a member of the power series family and is providing a lower bound estimator if the distribution is a mixture of a member of the power series family. However, if there is one-inflation Chao's estimator can severely overestimate as we show here. This is also illustrated by routinely collected country-wide data on family violence in the Netherlands. A new lower bound estimator is developed which involves only counts of twos and threes, thus avoiding the overestimation caused by one-inflation. We show that the new estimator is asymptotically unbiased for a power series distribution with and without one-inflation and provides a lower bound estimator under a mixture of power series distributions with and without one-inflation. For all estimators bias-adjusted versions are developed that reduce the bias considerably when the sample size is small. A simulation study compares the modified Chao estimator with the conventional estimator as well as with an estimator suggested by Chiu and Chao more recently. [ABSTRACT FROM AUTHOR]

Understanding infection dynamics of respiratory diseases requires the identification and quantification of behavioural, social and environmental factors that permit the transmission of these infections between humans. Little empirical information is available about contact patterns within real-world social networks, let alone on differences in these contact networks between populations that differ considerably on a socio-cultural level. Here we compared contact network data that were collected in the Netherlands and Thailand using a similar online respondent-driven method. By asking participants to recruit contact persons we studied network links relevant for the transmission of respiratory infections. We studied correlations between recruiter and recruited contacts to investigate mixing patterns in the observed social network components. In both countries, mixing patterns were assortative by demographic variables and random by total numbers of contacts. However, in Thailand participants reported overall more contacts which resulted in higher effective contact rates. Our findings provide new insights on numbers of contacts and mixing patterns in two different populations. These data could be used to improve parameterisation of mathematical models used to design control strategies. Although the spread of infections through populations depends on more factors, found similarities suggest that spread may be similar in the Netherlands and Thailand. [ABSTRACT FROM AUTHOR]

Understanding how communities assemble is a central goal of ecology. This is particularly relevant for communities of arbuscular mycorrhizal fungi (AMF), because the community composition of these beneficial plant symbionts influences important ecosystem processes. Moreover, AMF may be used as sensitive indicators of ecological soil quality if they respond to environmental variation in a predictable way. Here, we use a molecular profiling technique (T-RFLP of 25S rRNA gene fragments) to test which factors determine AM fungal community composition in 40 agricultural soils in the Netherlands. In particular, we test whether species richness, dominance structure and community nestedness are influenced by management type (in pairs of organically and conventionally farmed fields), and we examine the contribution of crop species (maize vs. potato), soil type (sand vs. clay-textured soils) and habitat (plant root vs. bulk soil) on AMF community characteristics. AMF richness varied from 1 to 11 taxa per field. Communities from species-poor fields were found to be subsets of those in richer fields, indicating nestedness and a progressive 'loss' from the species pool. AMF taxa richness and occurrence in soil and plant roots were highly correlated, and richness was related to management intensity (phosphate availability and grass-cropping history together explained 32% and 50% of richness in roots and soils). Soil type together with soil chemical parameters explained only 17% of variance in AMF community structure. We synthesize these results by discussing the potential contribution of a 'bottleneck effect' on AMF communities through increased stochastic effects under environmental stress. [ABSTRACT FROM AUTHOR]

In the Netherlands, there is a research tradition that measures fraud against regulations by interviewing eligible individuals using a survey. In these studies the sensitive questions about fraud are posed by using a randomized response method. The paper describes the results of a Dutch study into the consequences of replacing home interviews by trained interviewers with Internet-delivered interviews in a survey on fraud in the area of disability benefits. Both surveys used computer-assisted self-interviews with randomized response questions. This study has three goals: first to present the research tradition that makes use of randomized response, second to compare the results of home interviews and the Internet survey and finally to introduce an adapted weighted logistic regression method to test the relationship between the probability of fraud and explanatory variables. The results show that there are no systematic differences between modes of interview, either for estimates of the prevalence of fraud or for the identification of associated variables. These outcomes result in the conclusion that the Internet survey is a useful and cost-effective instrument for measuring fraud in a population, and that it is unlikely that replacing home interviews with the Internet survey will result in a significant break with tradition. [ABSTRACT FROM AUTHOR]

Reports on the prevalence and incidence of hepatitis C virus (HCV) infections among dialysis patients in the Netherlands. Testing of patients recruited from dialysis centers for antibodies and HCV RNA in 1995 and 1997. Analysis of seronegative serum samples by reverse-transcriptase polymerase chain reaction; Indications of nosocomial transmission; Interdependent risk factors.

Introduction: Data from single-center series suggest that a delay in time to radical cystectomy (RC) more than 3 months after diagnosis of muscle-invasive bladder cancer (MIBC) is associated with pathological upstaging and decreased survival. However, limited data is available from population-based studies. In this study, the effect of delayed RC was assessed in a nationwide cohort.Materials and Methods: Patients who underwent RC between 2006 and 2010 with primary clinical T2-T4N0M0 urothelial bladder cancer were selected using the Netherlands Cancer Registry database. Data from the Netherlands Cancer Registry was supplemented with data from the Nationwide Network and Registry of Histo- and Cytopathology database in case of incomplete information. The cohort was divided in patients who underwent RC ≤3 months (group I) vs. patients who underwent RC >3 months (group II). Median time from MIBC diagnosis to RC, variables associated with delayed RC >3 and the effect of delayed RC on staging and overall survival (OS) were evaluated in patients who underwent neoadjuvant therapy and patients who did not.Results: A total of 1,782 patients were included. Median follow-up time was 5.1 years for living patients and 1.3 years for deceased patients. Median time from MIBC diagnosis to RC was 50 days (interquartile range: 27 days) and 93% of patients underwent RC≤3 months. Patients older than 75 years (odds ratio [OR] = 0.50; 95% CI: 0.32-0.77), referred for RC (OR = 0.41; 95% CI: 0.26-0.69), and treated in a university hospital (OR = 0.34; 95% CI: 0.21-0.56) were less likely to undergo RC≤3 months. Pathologic upstaging rate (43.9% vs. 42.1%) and node-positive disease rate (20.2% vs. 21.7%) did not differ for group I and II. Delayed RC>3 months was not associated with decreased OS adjusting for confounding variables (hazard ratio = 1.16; 95% CI: 0.91-1.48; P = 0.25). Median time from MIBC diagnosis to RC in patients that received neoadjuvant therapy (n = 105) was 133 days (interquartile range: 62 days). Adjusting for confounding variables, delayed RC>3 months was not associated with OS (hazard ratio = 0.90; 95% CI: 0.45-1.82).Conclusions: The vast majority of patient underwent RC within 3 months after diagnosis of MIBC, as recommended in the European Association of Urology MIBC guideline. Delayed RC for more than 3 months had no adverse effect on staging and survival. [ABSTRACT FROM AUTHOR]

Background: Controversy exists on whether urinary tract infection (UTI) is a risk factor for urinary bladder cancer (UBC). Here, the association is investigated using data from one of the largest bladder cancer case-control studies worldwide., Methods: Information on (i) history and age at onset of regular cystitis ('regular low-UTI') and (ii) number and age at onset of UTI treated with antibiotics ('UTI-ab') from 1809 UBC patients and 4370 controls was analysed. Odds ratios (ORs) and 95% confidence intervals (CI) adjusted for age, education, smoking, and use of aspirin/ibuprofen were generated, for men and women separately., Results: Regular low-UTI was associated with an increased UBC risk (men: OR (95% CI) 6.6 (4.2-11); women: 2.7 (2.0-3.5)), with stronger effects in muscle-invasive UBC. Statistically significant decreased risks (ORs ∼0.65) were observed for up to five UTI-ab, specifically in those who (had) smoked and experienced UTI-ab at a younger age. In women, UTI experienced after menopause was associated with a higher UBC risk, irrespective of the number of episodes., Conclusions: Regular cystitis is positively associated with UBC risk. In contrast, a limited number of episodes of UTI treated with antibiotics is associated with decreased UBC risk, but not in never-smokers and postmenopausal women.