• Health-related locus of control and health behaviour among university students in North Rhine Westphalia, Germany

      Helmer, Stefanie M; Krämer, Alexander; Mikolajczyk, Rafael T (2012-12-29)
      Abstract Background Health control beliefs were postulated to be associated with health behaviour. However, the results of studies assessing these associations suggest that they might not be universal. Among young adults associations have been reported, but the evidence is limited. The objective of this analysis was to re-examine these associations in a sample of university students in Germany. Findings Data from a multicentre cross-sectional study among university students in North Rhine-Westphalia, Germany was used (N=3,306). The Multidimensional Health Locus of Control Scale with three dimensions (one internal and two external) and six aspects of health behaviour (smoking habits, alcohol use, drug consumption, being over-/ or underweight, physical activity, and importance of healthy nutrition) were evaluated. Students with stronger internal locus of control paid more attention to healthy nutrition and displayed a higher level of physical activity. Individuals with a stronger belief in health professionals were less likely to use drugs and paid more attention to healthy nutrition. Furthermore, higher scores in the second external locus of control dimension (beliefs in luck or chance) were associated with a higher likelihood of current smoking, lower physical activity and less attention to healthy nutrition. Conclusions Students engaged more strongly in unhealthy behaviour if they believed that luck determines health. In contrast, believing in having control over one’s own health was associated with more healthy behaviour. These findings support the need to consider health control beliefs while designing preventive strategies in this specific population.
    • Health-related locus of control and health behaviour among university students in North Rhine Westphalia, Germany.

      Helmer, Stefanie M; Krämer, Alexander; Mikolajczyk, Rafael T; Bremen Institute for Epidemiology and Prevention Research, University of Bremen, Bremen, Germany. rafael.mikolajczyk@helmholtz-hzi.de. (2012)
    • ["I cannot kiss my wife"- An Analysis of Daily Experiences of MRSA-carriers].

      Raupach-Rosin, H; Klett-Tammen, C J; Schmalz, O; Karch, A; Castell, S; Mikolajczyk, R; Helmholtz-Zentrum für Infektionsforschung GmbH, Inhoffenstr. 7, 38124 Braunschweig, Germany. (2016-12)
      Objectives: There are no data available on the quality of care after discharge from hospital and only limited data are available on the psychosocial effects of being an MRSA carrier within the German health system.Methods:Patients who tested positive for MRSA in the previous year were invited to take part in focus groups.Results:2 focus groups with a total of 9 MRSA-carriers were conducted. The level of knowledge about MRSA differed between participants. In some cases, lack of information led to uncertainty and inappropriate measures to counteract MRSA. Some participants restricted their social contacts, especially to children, in order to prevent transmission. Patients experienced stigmatization in the health care system more often in inpatient care than in the outpatient sector. Only in a few cases both eradication therapy and swabs for control purposes were carried out.Conclusions:Information about the appropriate treatment and management of MRSA should be made available to patients more easily; in particular, patients need to be informed that MRSA is no threat to healthy individuals. Despite the desire of MRSA-carriers to become MRSA negative, treatment and control of MRSA seem to have low priority in the ambulant health care sector in Germany.
    • Immune monitoring after pediatric liver transplantation - the prospective ChilSFree cohort study.

      Goldschmidt, Imeke; Karch, André; Mikolajczyk, Rafael; Mutschler, Frauke; Junge, Norman; Pfister, Eva Doreen; Möhring, Tamara; d'Antiga, Lorenzo; McKiernan, Patrick; Kelly, Deirdre; Debray, Dominique; McLin, Valérie; Pawlowska, Joanna; Hierro, Loreto; Daemen, Kerstin; Keil, Jana; Falk, Christine; Baumann, Ulrich; Helmholtz-Zentrum für Infektionsforschung GmbH, Inhoffenstr. 7, 38124 Braunschweig, Germany. (2018-05-16)
      Although trough levels of immunosuppressive drugs are largely used to monitor immunosuppressive therapy after solid organ transplantation, there is still no established tool that allows for a validated assessment of functional degree of immunosuppression or the identification of clinically relevant over- or under-immunosuppression, depending on graft homeostasis. Reliable non-invasive markers to predict biopsy proven acute rejection (BPAR) do not exist. Literature data suggest that longitudinal measurements of immune markers might be predictive of BPAR, but data in children are scarce. We therefore propose an observational prospective cohort study focusing on immune monitoring in children after liver transplantation. We aim to describe immune function in a cohort of children before and during the first year after liver transplantation and plan to investigate how the immune function profile is associated with clinical and laboratory findings. In an international multicenter prospective approach, children with end-stage liver disease who undergo liver transplantation are enrolled to the study and receive extensive immune monitoring before and at 1, 2, 3, 4 weeks and 3, 6, 12 months after transplantation, and whenever a clinically indicated liver biopsy is scheduled. Blood samples are analyzed for immune cell numbers and circulating levels of cytokines, chemokines and factors of angiogenesis reflecting immune cell activation. Statistical analysis will focus on the identification of trajectorial patterns of immune reactivity predictive for systemic non-inflammatory states, infectious complications or BPAR using joint modelling approaches. The ChilSFree study will help to understand the immune response after pLTx in different states of infection or rejection. It may provide insight into response mechanisms eventually facilitating immune tolerance towards the graft. Our analysis may yield an applicable immune panel for non-invasive early detection of acute cellular rejection, with the prospect of individually tailoring immunosuppressive therapy. The international collaborative set-up of this study allows for an appropriate sample size which is otherwise difficult to achieve in the field of pediatric liver transplantation.
    • Incidence and comparison of retrospective and prospective data on respiratory and gastrointestinal infections in German households.

      Schlinkmann, Kristin Maria; Bakuli, Abhishek; Mikolajczyk, Rafael T; Helmholtz Centre for infection research, Inhoffenstr. 7, 38124 Braunschweig, Germany. (2017-05-11)
      Acute respiratory infections (ARI) and acute gastrointestinal infections (AGI) are the most common childhood infections, and corresponding data can either be collected prospectively or retrospectively. The aim of this study was to estimate the incidence of respiratory and gastrointestinal episodes in German households with children attending day care and to compare results of prospective and retrospective data collection.
    • Incidence, prevalence and 1-year all-cause mortality of heart failure in Germany: a study based on electronic healthcare data of more than six million persons.

      Ohlmeier, Christoph; Mikolajczyk, Rafael T; Frick, Johann; Prütz, Franziska; Haverkamp, Wilhelm; Garbe, Edeltraut; Helmholtz Centre for infection research, Inhoffenstr. 7, 38124 Braunschweig, Germany. (2015-08)
      Heart failure (HF) continues to be a leading cause of morbidity and mortality in industrialized countries. Data on the epidemiology of HF are largely lacking for Germany. The aims of this study were to estimate the incidence and prevalence of HF in Germany, to estimate 1-year all-cause mortality in patients who received their first diagnosis of HF in hospital and to assess related risk factors.
    • Incidence, prevalence, and antithrombotic management of atrial fibrillation in elderly Germans.

      Ohlmeier, Christoph; Mikolajczyk, Rafael; Haverkamp, Wilhelm; Garbe, Edeltraut; Department of Clinical Epidemiology, Leibniz Institute for Prevention Research and Epidemiology - BIPS, Achterstraße 30, D - 28359 Bremen, Germany. (2013-10)
      Data on the epidemiology of atrial fibrillation (AF) and its antithrombotic management in elderly populations are scarce. The aims of this study were to estimate the incidence and prevalence of AF in the elderly in Germany and to describe antithrombotic management of AF cases.
    • Individual development of preschool children-prevalences and determinants of delays in Germany: a cross-sectional study in Southern Bavaria.

      Stich, Heribert L; Baune, Bernhard Th; Caniato, Riccardo N; Mikolajczyk, Rafael T; Krämer, Alexander (2012)
      Even minor abnormalities of early child development may have dramatic long term consequences. Accurate prevalence rates for a range of developmental impairments have been difficult to establish. Since related studies have used different methodological approaches, direct comparisons of the prevalence of developmental delays are difficult. The understanding of the key factors affecting child development, especially in preschool aged children remains limited. We used data from school entry examinations in Bavaria to measure the prevalence of developmental impairments in pre-school children beginning primary school in 1997-2009.
    • Infection prevention at preschool age - What is reasonable? [Infektionsprävention im Kindergartenalter -Was ist sinnvoll?]

      Schlinkmann, K.M.; Raupach-Rosin, H.; Hübner, J., (2016-01)
      Akute respiratorische und gastrointestinale Infektionen stellen die am weitesten verbreiteten Infektionserkrankungen im Kindesalter dar und generieren hohe Kosten. Bezüglich des Immunsystems ist neben der Infektionsabwehr auch die Immuntoleranz zu beachten. Daraus ergibt sich die Frage nach einer Ausgestaltung der Infektionsprävention, bei der negative Effekte auf die Immuntoleranz vermieden werden. Eine Handreichung dazu bieten die Hygienehypothese und die „old friends“ Theorie, die die Unterschiede in der Rolle der Pathogene für die Entwicklung des Immunsystems mit der gemeinsamen Evolution erklärt. Daraus lassen sich Implikationen für die Infektionsprävention ableiten: Bezüglich der Mikroorganismen, die für die Ausbildung der Toleranz verantwortlich sind (sog. old friends, z.B. Mikroorganismen, die das Mikrobiom bilden), können sich übertriebene Hygienemaßnahmen negativ auswirken. Pathogene, die eine dauerhafte Immunität auslösen oder tödlich verlaufen können (sog. crowd infections, z.B. Masern) haben diese Rolle nicht – angesichts der Risiken sollte hier eine spezifische Prävention mittels Impfung erfolgen. Die meisten akuten respiratorischen und gastrointestinalen Infektionen fallen in eine weitere Gruppe ohne bleibende Immunantwort (z.B. Rhinovirusinfektionen), deren Rolle für die Immuntoleranz bisher unklar ist. Für diese Infektionen können unspezifische Präventionsmaßnahmen eingesetzt werden. Gesicherte Evidenz liegt für die Effektivität von Handhygiene sowie von Barriere- und Isolationsmaßnahmen zur Verhinderung der Infektionsübertragung vor. Hingegen gibt es für Maßnahmen zur Stärkung der Immunität keine oder bestenfalls kontroverse Evidenz. Der traditionelle Zusammenhang zwischen Kälte und Erkältung erscheint fraglich und daher auch die Bedeutsamkeit der entsprechenden Präventionsmaßnahmen. Unklar ist, in welchem Umfang einzelne Maßnahmen von Eltern eingesetzt werden, und ob die Exposition gegenüber den leichten akuten Infektionen doch immunologisch eine Rolle spielt. 2
    • Influence of demographic changes on the impact of vaccination against varicella and herpes zoster in Germany - a mathematical modelling study.

      Horn, Johannes; Damm, Oliver; Greiner, Wolfgang; Hengel, Hartmut; Kretzschmar, Mirjam E; Siedler, Anette; Ultsch, Bernhard; Weidemann, Felix; Wichmann, Ole; Karch, André; Mikolajczyk, Rafael T; elmholtz-Zentrum für Infektionsforschung GmbH, Inhoffenstr. 7, 38124 Braunschweig, Germany. (2018)
      Epidemiological studies suggest that reduced exposure to varicella might lead to an increased risk for herpes zoster (HZ). Reduction of exposure to varicella is a consequence of varicella vaccination but also of demographic changes. We analyzed how the combination of vaccination programs and demographic dynamics will affect the epidemiology of varicella and HZ in Germany over the next 50 years.
    • Measuring inter-rater reliability for nominal data - which coefficients and confidence intervals are appropriate?

      Zapf, Antonia; Castell, Stefanie; Morawietz, Lars; Karch, André; Helmholtz Centre for infection research, Inhoffenstr. 7, 38124 Braunschweig, Germany. (2016)
      Reliability of measurements is a prerequisite of medical research. For nominal data, Fleiss' kappa (in the following labelled as Fleiss' K) and Krippendorff's alpha provide the highest flexibility of the available reliability measures with respect to number of raters and categories. Our aim was to investigate which measures and which confidence intervals provide the best statistical properties for the assessment of inter-rater reliability in different situations.
    • Mortality in the German Pharmacoepidemiological Research Database (GePaRD) compared to national data in Germany: results from a validation study.

      Ohlmeier, Christoph; Langner, Ingo; Hillebrand, Kathrin; Schmedt, Niklas; Riedel, Oliver; Garbe, Edeltraut (2015)
      Electronic healthcare databases are of increasing importance in health research and mortality is one of the most relevant outcomes. However, data in these databases need to be validated, since they are often generated for reimbursement purposes. The aims of this study were to compare mortality figures from the German Pharmacoepidemiological Research Database (GePaRD) on an aggregated level with external data from the Federal Statistical Office of Germany (FSOG) and to assess consistency of records of death from core data and hospital data within GePaRD.
    • Optimized Management of Endovascular Treatment for Acute Ischemic Stroke.

      Schregel, Katharina; Behme, Daniel; Tsogkas, Ioannis; Knauth, Michael; Maier, Ilko; Karch, André; Mikolajczyk, Rafael; Bähr, Mathias; Schäper, Jörn; Hinz, José; Liman, Jan; Psychogios, Marios-Nikos; HZI,Helmholtz-Zentrum für Infektionsforschung GmbH, Inhoffenstr. 7,38124 Braunschweig, Germany. (2018-01-18)
      This manuscript describes a streamlined protocol for the management of patients with acute ischemic stroke, which aims at the minimization of time from hospital admission to reperfusion. Rapid restoration of cerebral blood flow is essential for the outcomes of patients with acute ischemic stroke. Endovascular treatment (EVT) has become the standard of care to accomplish this in patients with acute stroke due to large vessel occlusion (LVO). To achieve reperfusion of ischemic brain regions as fast as possible, all in-hospital time delays have to be carefully avoided. Therefore, management of patients with acute ischemic stroke was optimized with an interdisciplinary standard operating procedure (SOP). Stroke neurologists, diagnostic as well as interventional neuroradiologists, and anesthesiologists streamlined all necessary processes from patient admission and diagnosis to EVT of eligible patients. Target times for every step were established. Actually achieved times were prospectively recorded along with clinical data and imaging scores for all endovascularly treated stroke patients. These data were regularly analyzed and discussed in interdisciplinary team meetings. Potential issues were evaluated and all staff involved was trained to adhere to the SOP. This streamlined patient management approach and enhanced interdisciplinary collaboration reduced time from patient admission to reperfusion significantly and was accompanied by a beneficial effect on clinical outcomes.
    • Partial verification bias and incorporation bias affected accuracy estimates of diagnostic studies for biomarkers that were part of an existing composite gold standard.

      Karch, Annika; Koch, Armin; Zapf, Antonia; Zerr, Inga; Karch, André; Helmholtz-Zentrum für Infektionsforschung GmbH, Inhoffenstr. 7, 38124 Braunschweig, Germany. (2016-10)
      To investigate how choice of gold standard biases estimates of sensitivity and specificity in studies reassessing the diagnostic accuracy of biomarkers that are already part of a lifetime composite gold standard (CGS).
    • Poor knowledge of vaccination recommendations and negative attitudes towards vaccinations are independently associated with poor vaccination uptake among adults - Findings of a population-based panel study in Lower Saxony, Germany.

      Akmatov, Manas K; Rübsamen, Nicole; Deyneko, Igor V; Karch, André; Mikolajczyk, Rafael T; Helmholtz-Zentrum für Infektionsforschung GmbH, Inhoffenstr. 7, 38124 Braunschweig, Germany. (2018)
      The aims of this study were to (a) assess knowledge of official vaccination recommendations and attitudes towards vaccinations among adults and (b) examine their association with vaccination uptake among adults.
    • Population-level impact, herd immunity, and elimination after human papillomavirus vaccination: a systematic review and meta-analysis of predictions from transmission-dynamic models.

      Brisson, Marc; Bénard, Élodie; Drolet, Mélanie; Bogaards, Johannes A; Baussano, Iacopo; Vänskä, Simopekka; Jit, Mark; Boily, Marie-Claude; Smith, Megan A; Berkhof, Johannes; Canfell, Karen; Chesson, Harrell W; Burger, Emily A; Choi, Yoon H; De Blasio, Birgitte Freiesleben; De Vlas, Sake J; Guzzetta, Giorgio; Hontelez, Jan A C; Horn, Johannes; Jepsen, Martin R; Kim, Jane J; Lazzarato, Fulvio; Matthijsse, Suzette M; Mikolajczyk, Rafael T; Pavelyev, Andrew; Pillsbury, Matthew; Shafer, Leigh Anne; Tully, Stephen P; Turner, Hugo C; Usher, Cara; Walsh, Cathal; Helmholtz Zentrum für Infektionsforschung GmbH, Inhoffenstr. 7, 38124 Braunschweig, Germany. (2016-11)
      Modelling studies have been widely used to inform human papillomavirus (HPV) vaccination policy decisions; however, many models exist and it is not known whether they produce consistent predictions of population-level effectiveness and herd effects. We did a systematic review and meta-analysis of model predictions of the long-term population-level effectiveness of vaccination against HPV 16, 18, 6, and 11 infection in women and men, to examine the variability in predicted herd effects, incremental benefit of vaccinating boys, and potential for HPV-vaccine-type elimination.
    • Predictors of the patient-centered outcomes of surgical carpal tunnel release - a prospective cohort study.

      Conzen, Catharina; Conzen, Michael; Rübsamen, Nicole; Mikolajczyk, Rafael; Helmholtz Centre for infection research, Inhoffenstr. 7, 38124 Braunschweig, Germany. (2016)
      Carpal tunnel syndrome (CTS) causes a substantial burden of disease in society. While CTS can be resolved by surgical carpal tunnel release, it still remains unclear as to what degree outcomes depend on patients' characteristics. This study assesses patient-centered outcomes after surgical carpal tunnel release in a large outpatient clinic in Germany.
    • Proposing an empirically justified reference threshold for blood culture sampling rates in intensive care units.

      Karch, André; Castell, Stefanie; Schwab, Frank; Geffers, Christine; Bongartz, Hannah; Brunkhorst, Frank M; Gastmeier, Petra; Mikolajczyk, Rafael T; Helmholtz Centre for infection research, Inhoffenstr. 7, 38124 Braunschweig, Germany. (2015-02)
      Early and appropriate blood culture sampling is recommended as a standard of care for patients with suspected bloodstream infections (BSI) but is rarely taken into account when quality indicators for BSI are evaluated. To date, sampling of about 100 to 200 blood culture sets per 1,000 patient-days is recommended as the target range for blood culture rates. However, the empirical basis of this recommendation is not clear. The aim of the current study was to analyze the association between blood culture rates and observed BSI rates and to derive a reference threshold for blood culture rates in intensive care units (ICUs). This study is based on data from 223 ICUs taking part in the German hospital infection surveillance system. We applied locally weighted regression and segmented Poisson regression to assess the association between blood culture rates and BSI rates. Below 80 to 90 blood culture sets per 1,000 patient-days, observed BSI rates increased with increasing blood culture rates, while there was no further increase above this threshold. Segmented Poisson regression located the threshold at 87 (95% confidence interval, 54 to 120) blood culture sets per 1,000 patient-days. Only one-third of the investigated ICUs displayed blood culture rates above this threshold. We provided empirical justification for a blood culture target threshold in ICUs. In the majority of the studied ICUs, blood culture sampling rates were below this threshold. This suggests that a substantial fraction of BSI cases might remain undetected; reporting observed BSI rates as a quality indicator without sufficiently high blood culture rates might be misleading.
    • Regional variation in caesarean deliveries in Germany and its causes.

      Mikolajczyk, Rafael T; Schmedt, Niklas; Zhang, Jun; Lindemann, Christina; Langner, Ingo; Garbe, Edeltraut; Department of Clinical Epidemiology, Leibniz Institute for Prevention Research and Epidemiology-BIPS, Bremen, Germany. Rafael.mikolajczyk@helmholtz-hzi.de. (2013)
      Determinants of regional variation in caesarean sections can contribute explanations for the observed overall increasing trend of caesarean sections. We assessed which mechanism explains the higher rate of caesarean sections in the former West than East Germany: a more liberal use of caesarean sections in the case of relative indications or more common caesarean sections without indications.
    • The Risk of Hospitalizations with Injury Diagnoses in a Matched Cohort of Children and Adolescents with and without Attention Deficit/Hyperactivity Disorder in Germany: A Database Study.

      Lindemann, Christina; Langner, Ingo; Banaschewski, Tobias; Garbe, Edeltraut; Mikolajczyk, Rafael T; Helmholtz-Zentrum für Infektionsforschung GmbH, Inhoffenstr.7, 38124 Braunschweig, Germany. (2017)
      Attention deficit/hyperactivity disorder (ADHD) is a common neuropsychiatric disorder in children and adolescents worldwide, and children with ADHD have elevated risk of injuries. Our aim was to assess the risk of hospitalizations with injury diagnoses and their various subtypes in children and adolescents with newly diagnosed ADHD compared to those without ADHD, as well as to study sex effects on this risk in the setting of the German health care system.