[Show abstract][Hide abstract] ABSTRACT: At present, most documentation forms and item catalogs in healthcare are not accessible to the public. This applies to assessment forms of routine patient care as well as case report forms (CRFs) of clinical and epidemiological studies. On behalf of the German chairs for Medical Informatics, Biometry and Epidemiology six recommendations to developers and users of documentation forms in healthcare were developed. Open access to medical documentation forms could substantially improve information systems in healthcare and medical research networks. Therefore these forms should be made available to the scientific community, their use should not be unduly restricted, they should be published in a sustainable way using international standards and sources of documentation forms should be referenced in scientific publications.
Methods of Information in Medicine 06/2015; 24(4). DOI:10.3414/ME15-05-0007 · 1.08 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Background
Cobalt contact sensitization in consecutively tested patients is common. The sources of exposure, and thus clinical relevance, are mostly unclear.Objective
To examine (i) long-term time trends of sensitization, (ii) risk factors that may point to relevant exposures, and (iii) coupling with nickel sensitization.Methods
Data of all patients patch tested with cobalt(II) chloride hexahydrate (1% pet.) between 1992 and 2012 (n = 185 050) in the Information Network of Departments of Dermatology (IVDK, www.ivkd.org) were subjected to descriptive stratified and Poisson regression analysis.ResultsThe overall prevalence of positive patch test reactions was 5.23% (95% confidence interal 5.13–5.33%). Regarding time trends, there were significant increases for males aged 18–44 years and for females aged ≥45 years, and a significant variation of co-reactivity with nickel over time. Female sex almost doubled the risk of sensitization; age ≥45 years was associated with a 30% decrease in the risk of positive patch test reactions to cobalt, and atopic eczema with an approximately 20% increase.Conclusions
Notwithstanding some diagnostic difficulties with the test preparation, a persistent, notable proportion of cobalt sensitization, isolated or coupled with nickel allergy, can be observed. This warrants further in-depth research into causative exposures, both at the workplace and in consumers.
[Show abstract][Hide abstract] ABSTRACT: A high number of melanocytic naevi is one of the major risk factors for cutaneous melanoma. Therefore, counting the number of acquired naevi could be a useful strategy to identify individuals at an increased risk for targeted skin cancer screening. The aim of this study was to assess agreement between naevus self-counts and counts of trained examiners as well as to analyse potential determinants of the magnitude of agreement. In a large cross-sectional survey (n=1772), university students counted their naevi on both arms and were additionally examined by specifically trained examiners in a mutually blinded manner. Further data on other melanoma risk factors such as skin phototype, hair colour or freckling were collected by a questionnaire. The relative difference between the two naevus counts and the ratio of the counts were calculated to quantify agreement. Regression modelling was performed to identify independent determinants of agreement. The overall agreement was moderate, with participants counting on average 14% more naevi than the examiners. In terms of the potential determinants associated with agreement, skin type and medical education showed a strong effect. The difference in naevus counts was significantly larger for individuals with lighter skin types compared with those with a dark skin (Fitzpatrick type IV), and medical students yielded a naevus count more similar to the examiner's count than nonmedical students. Naevus self-counts can only provide a rough estimate of the number of naevi, but may not be accurate enough to reliably identify a high-risk group for melanoma screening, especially in individuals with light skin types.
Melanoma Research 07/2014; 24(6). DOI:10.1097/CMR.0000000000000111 · 2.10 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Public health campaigns have improved knowledge on UVR-associated skin cancer risk and increased sun protection awareness. However, tanned skin is still a common beauty ideal. The relationship between knowledge, attitudes and protective behavior is not fully understood yet. A population-based survey was thus performed in the district of Erlangen involving 2,619 parents of 3- to 6-year old children. By means of a self-administered standardized questionnaire parental knowledge about risk factors for skin cancer, their attitudes towards tanning and details of protective measures taken for their children were assessed. The study analyzed specifically the impact of parental tanning attitudes on sun-protective measures for their children while controlling for parental knowledge about skin cancer risk factors. While parental knowledge was significantly (inversely) associated with agreement to the statement "Tanned skin is healthy skin", this was not the case for "Tanning makes me look better". Overall, tanning affirmative attitudes were inversely associated with protective measures taken for the children, whereas parental knowledge had a positive impact on sun protection at the beach only. Multivariable analyses provided evidence for an effect of parental attitude on protective behavior independent of parental knowledge. Tanning attitudes and tanned skin as the misguided ideal of beauty need to be addressed in future public health campaigns to enhance the effectiveness of preventive activities in changing sun protective behavior.
International Journal of Environmental Research and Public Health 05/2014; 11(5):4768-81. DOI:10.3390/ijerph110504768 · 2.06 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Boosting algorithms to simultaneously estimate and select predictor effects
in statistical models have gained substantial interest during the last decade.
This review article aims to highlight recent methodological developments
regarding boosting algorithms for statistical modelling especially focusing on
topics relevant for biomedical research. We suggest a unified framework for
gradient boosting and likelihood-based boosting (statistical boosting) which
have been addressed strictly separated in the literature up to now. Statistical
boosting algorithms have been adapted to carry out unbiased variable selection
and automated model choice during the fitting process and can nowadays be
applied in almost any possible type of regression setting in combination with a
large amount of different types of predictor effects. The methodological
developments on statistical boosting during the last ten years can be grouped
into three different lines of research: (i) efforts to ensure variable
selection leading to sparser models, (ii) developments regarding different
types of predictor effects and their selection (model choice), (iii) approaches
to extend the statistical boosting framework to new regression settings.
Methods of Information in Medicine 03/2014; 53(5). DOI:10.3414/ME13-01-0123 · 1.08 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The concept of boosting emerged from the field of machine learning. The basic
idea is to boost the accuracy of a weak classifying tool by combining various
instances into a more accurate prediction. This general concept was later
adapted to the field of statistical modelling. This review article attempts to
highlight this evolution of boosting algorithms from machine learning to
statistical modelling. We describe the AdaBoost algorithm for classification as
well as the two most prominent statistical boosting approaches, gradient
boosting and likelihood-based boosting. Although both appraoches are typically
treated separately in the literature, they share the same methodological roots
and follow the same fundamental concepts. Compared to the initial machine
learning algorithms, which must be seen as black-box prediction schemes,
statistical boosting result in statistical models which offer a
straight-forward interpretation. We highlight the methodological background and
present the most common software implementations.
Methods of Information in Medicine 03/2014; 53(5). DOI:10.3414/ME13-01-0122 · 1.08 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Background
Cosmetics for bleaching, waving/relaxing and dyeing hair contain well-known allergens, leading to a substantial number of cases of allergic contact dermatitis.Objective
To compare the frequency of important contact allergens (i) between two distinct groups of exposed patients, and (ii) with previous surveillance data.Methods
On the basis of data collected by the Information Network of Departments of Dermatology (IVDK; www.ivkd.org) between 2007 and 2012 in 824 female hairdressers and 2067 female clients, the current spectrum of contact sensitization to ingredients of hair cosmetics, as contained in different pertinent series, is described.ResultsA similar burden of sensitization as in previous analyses was observed, but with some increase in sensitization to oxidative hair dye components in clients. Some allergens mainly affected hairdressers, such as ammonium persulfate (18.7% positive) and glyceryl monothioglycolate (GMTG; still 4.7% positive, with a few cases also in young hairdressers, despite removal from the German market).Conclusions
Hair dyes remain important contact allergens, despite various attempts by the cosmetic industry to introduce hair dyes with lower allergenic potential. The re-emergence of GMTG as an occupational allergen should be considered as a warning signal (‘sentinel event’) prompting close monitoring.
[Show abstract][Hide abstract] ABSTRACT: Hydroxyisohexyl 3-cyclohexene carboxaldehyde (HICC) is a synthetic fragrance chemical and an important contact allergen, at least in Europe. Despite this importance, little is known about risk factors associated with this allergen.
To examine factors from the history and clinical presentation of patch tested patients associated with HICC sensitization.
Contact allergy surveillance data of 95 637 patients collected by the Information Network of Departments of Dermatology (IVDK, www.ivkd.org) in 2002-2011 were analysed. Point and interval estimates of the relative risk were derived from multifactorial logistic regression modelling.
The overall prevalence of HICC sensitization was 2.24%. The strongest risk factors were polysensitization and dermatitis of the axillae, followed by dermatitis at other sites. No consistent and significant time trend was observed in this analysis. As compared with the youngest patients, the odds of HICC sensitization increased approximately three-fold in the 52-67-year age group, and strongly declined with further increasing age.
The risk pattern with regard to age and affected anatomical site differed from that observed with other fragrance screening allergens. Cosmetic exposure, as broadly defined here, was a stronger and more prevalent individual risk factor than occupational exposure.
[Show abstract][Hide abstract] ABSTRACT: No observed event is a special, but not uncommon, result in patch test studies. The interpretation of such findings depends critically on the sample size (n) of the investigation, and is statistically addressed by the use of confidence intervals (CIs).
To define the statistically correct method of calculating a CI with a confidence level of 1 - α, where α denotes the tolerated statistical error probability, for an observed prevalence of 0%.
A literature survey and evaluation of the statistical methods was conducted. The popular statistical software packages spss™ and sas™ were examined with regard to the methods implemented, and the results obtained, for estimating such CIs in this special case.
The evaluation identified [0; 1 - α(1/n) ], which is well approximated by [0; 3/n] for α = 0.05, as an appropriate method to compute a CI with a confidence level of 1 - α. The resulting CI is an exact one, and more efficient than standard solutions. Popular statistical software such as spss™ and sas™ offers only various inefficient or even invalid procedures, but does not include this method.
It is easy to calculate a CI for an observed prevalence of 0% obtained in some studies. Such a CI facilitates the interpretation of such a finding, as it puts the observed zero result into adequate statistical perspective.
[Show abstract][Hide abstract] ABSTRACT: This study evaluated the psychometric properties of the German version of the 21-item Exercise Dependence Scale (EDS-G), which was administered in a large representative German sample (N = 1,611). In order to examine convergent validity, we also asked participants to answer the Eating Disorder Examination-Questionnaire (EDE-Q). To investigate the discriminant validity, clients of fitness centers (N = 129), sport students (N = 85), and medical students (N = 129) filled out the EDS-G. In this German population-based sample, the seven-factor structure suggested by the original authors as well as a higher-order model (7 + 1 factor model) were supported. The total EDS-G scale showed an excellent internal reliability and was positively related to the EDE-Q total and subscale scores. The EDS-G scores differentiated between samples with varying degrees of exercise. In summary, the results indicate that the EDS-G is a psychometrically sound and potentially valid brief measure for the assessment of exercise dependence symptoms. (PsycINFO Database Record (c) 2013 APA, all rights reserved)
European Journal of Psychological Assessment 07/2013; 29(3):213. DOI:10.1027/1015-5759/a000144 · 2.53 Impact Factor