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Featured researches published by André Karch.


JAMA Pediatrics | 2016

Top 25 Global Causes of Disability-Adjusted Life-Years (DALYs) in Children Younger Than 5 Years, Both Sexes, 1990 and 2013

André Karch

IMPORTANCE The literature focuses on mortality among children younger than 5 years. Comparable information on nonfatal health outcomes among these children and the fatal and nonfatal burden of diseases and injuries among older children and adolescents is scarce. OBJECTIVE To determine levels and trends in the fatal and nonfatal burden of diseases and injuries among younger children (aged <5 years), older children (aged 5-9 years), and adolescents (aged 10-19 years) between 1990 and 2013 in 188 countries from the Global Burden of Disease (GBD) 2013 study. EVIDENCE REVIEW Data from vital registration, verbal autopsy studies, maternal and child death surveillance, and other sources covering 14,244 site-years (ie, years of cause of death data by geography) from 1980 through 2013 were used to estimate cause-specific mortality. Data from 35,620 epidemiological sources were used to estimate the prevalence of the diseases and sequelae in the GBD 2013 study. Cause-specific mortality for most causes was estimated using the Cause of Death Ensemble Model strategy. For some infectious diseases (eg, HIV infection/AIDS, measles, hepatitis B) where the disease process is complex or the cause of death data were insufficient or unavailable, we used natural history models. For most nonfatal health outcomes, DisMod-MR 2.0, a Bayesian metaregression tool, was used to meta-analyze the epidemiological data to generate prevalence estimates. FINDINGS Of the 7.7 (95% uncertainty interval [UI], 7.4-8.1) million deaths among children and adolescents globally in 2013, 6.28 million occurred among younger children, 0.48 million among older children, and 0.97 million among adolescents. In 2013, the leading causes of death were lower respiratory tract infections among younger children (905.059 deaths; 95% UI, 810,304-998,125), diarrheal diseases among older children (38,325 deaths; 95% UI, 30,365-47,678), and road injuries among adolescents (115,186 deaths; 95% UI, 105,185-124,870). Iron deficiency anemia was the leading cause of years lived with disability among children and adolescents, affecting 619 (95% UI, 618-621) million in 2013. Large between-country variations exist in mortality from leading causes among children and adolescents. Countries with rapid declines in all-cause mortality between 1990 and 2013 also experienced large declines in most leading causes of death, whereas countries with the slowest declines had stagnant or increasing trends in the leading causes of death. In 2013, Nigeria had a 12% global share of deaths from lower respiratory tract infections and a 38% global share of deaths from malaria. India had 33% of the worlds deaths from neonatal encephalopathy. Half of the worlds diarrheal deaths among children and adolescents occurred in just 5 countries: India, Democratic Republic of the Congo, Pakistan, Nigeria, and Ethiopia. CONCLUSIONS AND RELEVANCE Understanding the levels and trends of the leading causes of death and disability among children and adolescents is critical to guide investment and inform policies. Monitoring these trends over time is also key to understanding where interventions are having an impact. Proven interventions exist to prevent or treat the leading causes of unnecessary death and disability among children and adolescents. The findings presented here show that these are underused and give guidance to policy makers in countries where more attention is needed.


Brain | 2012

Cerebrospinal fluid biomarker supported diagnosis of Creutzfeldt-Jakob disease and rapid dementias: a longitudinal multicentre study over 10 years.

Katharina Stoeck; Pascual Sánchez-Juan; Joanna Gawinecka; Alison Green; Anna Ladogana; Maurizio Pocchiari; Raquel Sánchez-Valle; Eva Mitrova; Theodor Sklaviadis; Jerzy Kulczycki; D. Slivarichová; Albert Saiz; Miguel Calero; Richard Knight; Adriano Aguzzi; Jean-Louis Laplanche; Katell Peoc’h; Gabi Schelzke; André Karch; Cornelia van Duijn; Inga Zerr

To date, cerebrospinal fluid analysis, particularly protein 14-3-3 testing, presents an important approach in the identification of Creutzfeldt–Jakob disease cases. However, one special point of criticism of 14-3-3 testing is the specificity in the differential diagnosis of rapid dementia. The constant observation of increased cerebrospinal fluid referrals in the national surveillance centres over the last years raises the concern of declining specificity due to higher number of cerebrospinal fluid tests performed in various neurological conditions. Within the framework of a European Community supported longitudinal multicentre study (‘cerebrospinal fluid markers’) we analysed the spectrum of rapid progressive dementia diagnoses, their potential influence on 14-3-3 specificity as well as results of other dementia markers (tau, phosphorylated tau and amyloid-β1–42) and evaluated the specificity of 14-3-3 in Creutzfeldt–Jakob disease diagnosis for the years 1998–2008. A total of 29 022 cerebrospinal fluid samples were analysed for 14-3-3 protein and other cerebrospinal fluid dementia markers in patients with rapid dementia and suspected Creutzfeldt–Jakob disease in the participating centres. In 10 731 patients a definite diagnosis could be obtained. Protein 14-3-3 specificity was analysed for Creutzfeldt–Jakob disease with respect to increasing cerebrospinal fluid tests per year and spectrum of differential diagnosis. Ring trials were performed to ensure the comparability between centres during the reported time period. Protein 14-3-3 test specificity remained high and stable in the diagnosis of Creutzfeldt–Jakob disease during the observed time period across centres (total specificity 92%; when compared with patients with definite diagnoses only: specificity 90%). However, test specificity varied with respect to differential diagnosis. A high 14-3-3 specificity was obtained in differentiation to other neurodegenerative diseases (95–97%) and non-neurological conditions (91–97%). We observed lower specificity in the differential diagnoses of acute neurological diseases (82–87%). A marked and constant increase in cerebrospinal fluid test referrals per year in all centres did not influence 14-3-3 test specificity and no change in spectrum of differential diagnosis was observed. Cerebrospinal fluid protein 14-3-3 detection remains an important test in the diagnosis of Creutzfeldt–Jakob disease. Due to a loss in specificity in acute neurological events, the interpretation of positive 14-3-3 results needs to be performed in the clinical context. The spectrum of differential diagnosis of rapid progressive dementia varied from neurodegenerative dementias to dementia due to acute neurological conditions such as inflammatory diseases and non-neurological origin.


Molecular Neurobiology | 2015

Characteristic CSF prion seeding efficiency in humans with prion diseases.

Maria Cramm; Matthias Schmitz; André Karch; Saima Zafar; Daniela Varges; Eva Mitrova; Bjoern Schroeder; Alex J. Raeber; Franziska Kuhn; Inga Zerr

The development of in vitro amplification systems allows detecting femtomolar amounts of prion protein scrapie (PrPSc) in human cerebrospinal fluid (CSF). We performed a CSF study to determine the effects of prion disease type, codon 129 genotype, PrPSc type, and other disease-related factors on the real-time quaking-induced conversion (RT-QuIC) response. We analyzed times to 10,000 relative fluorescence units, areas under the curve and the signal maximum of RT-QuIC response as seeding parameters of interest. Interestingly, type of prion disease (sporadic vs. genetic) and the PRNP mutation (E200K vs. V210I and FFI), codon 129 genotype, and PrPSc type affected RT-QuIC response. In genetic forms, type of mutation showed the strongest effect on the observed outcome variables. In sporadic CJD, MM1 patients displayed a higher RT-QuIC signal maximum compared to MV1 and VV1. Age and gender were not associated with RT-QuIC signal, but patients with a short disease course showed a higher seeding efficiency of the RT-QuIC response. This study demonstrated that PrPSc characteristics in the CSF of human prion disease patients are associated with disease subtypes and rate of decline as defined by disease duration.


Alzheimers & Dementia | 2016

Comparative analysis of cerebrospinal fluid biomarkers in the differential diagnosis of neurodegenerative dementia

Franc Llorens; Matthias Schmitz; André Karch; Maria Cramm; Peter Lange; Kerim Gherib; Daniela Varges; Christian Schmidt; Inga Zerr; Katharina Stoeck

The analysis of cerebrospinal fluid biomarkers gains importance in clinical routine and is effective in substantiating dementia diagnosis in the differential diagnostic context.


Emerging Infectious Diseases | 2015

Ebola risk perception in Germany, 2014.

Nicole Rübsamen; Stefanie Castell; Johannes Horn; André Karch; Jördis J Ott; Heike Raupach-Rosin; Beate Zoch; Gérard Krause; Rafael T. Mikolajczyk

Knowledge about actual risks was poor, creating the potential for inappropriate behavior changes.


PLOS ONE | 2015

Effect of beta-blocker therapy on the risk of infections and death after acute stroke--a historical cohort study.

Ilko L. Maier; André Karch; Rafael T. Mikolajczyk; Mathias Bähr; Jan Liman

Background Infections are a frequent cause for prolonged hospitalization and increased mortality after stroke. Recent studies revealed a stroke-induced depression of the peripheral immune system associated with an increased susceptibility for infections. In a mice model for stroke, this immunosuppressive effect was reversible after beta-blocker administration. The aim of our study was to investigate the effect of beta-blocker therapy on the risk of infections and death after stroke in humans. Methods 625 consecutive patients with ischemic or hemorrhagic stroke, admitted to a university hospital stroke unit, were included in this historical cohort study. The effect of beta-blocker therapy on post-stroke pneumonia, urinary tract infections and death was investigated using multivariable Poisson and Cox regression models. Results 553 (88.3%) patients were admitted with ischemic stroke, the remaining 72 (11.7%) had a hemorrhagic stroke. Median baseline NIHSS was 8 (IQR 5–16) points. 301 (48.2%) patients received beta-blocker therapy. There was no difference in the risk of post-stroke pneumonia between patients with and without beta-blocker therapy (Rate Ratio = 1.00, 95%CI 0.77–1.30, p = 0.995). Patients with beta-blocker therapy showed a decreased risk for urinary tract infections (RR = 0.65, 95%CI 0.43–0.98, p = 0.040). 7-days mortality did not differ between groups (Hazard Ratio = 1.36, 95%CI 0.65–2.77, p = 0.425), while patients with beta-blocker therapy showed a higher 30-days mortality (HR = 1.93, 95%CI 1.20–3.10, p = 0.006). Conclusions Beta-blocker therapy did not reduce the risk for post-stroke pneumonia, but significantly reduced the risk for urinary tract infections. Different immune mechanisms underlying both diseases might explain these findings that need to be confirmed in future studies.


Neurology | 2015

Development of the Standards of Reporting of Neurological Disorders (Strond) Checklist: A Guideline for the Reporting of Incidence and Prevalence Studies in Neuroepidemiology

Derrick Bennett; Carol Brayne; Valery L. Feigin; Suzanne Barker-Collo; Michael Brainin; Daniel Davis; Valentina Gallo; N Jetté; André Karch; J F Kurtzke; Pablo M. Lavados; Giancarlo Logroscino; Gabriele Nagel; Preux P-M.; P M Rothwell; L W Svenson

Background: Incidence and prevalence studies of neurologic disorders play an important role in assessing the burden of disease and planning services. However, the assessment of disease estimates is hindered by problems in reporting for such studies. Despite a growth in published reports, existing guidelines relate to analytical rather than descriptive epidemiologic studies. There are also no user-friendly tools (e.g., checklists) available for authors, editors, and peer reviewers to facilitate best practice in reporting of descriptive epidemiologic studies for most neurologic disorders. Objective: The Standards of Reporting of Neurological Disorders (STROND) is a guideline that consists of recommendations and a checklist to facilitate better reporting of published incidence and prevalence studies of neurologic disorders. Methods: A review of previously developed guidance was used to produce a list of items required for incidence and prevalence studies in neurology. A 3-round Delphi technique was used to identify the “basic minimum items” important for reporting, as well as some additional “ideal reporting items.” An e-consultation process was then used in order to gauge opinion by external neuroepidemiologic experts on the appropriateness of the items included in the checklist. Findings: Of 38 candidate items, 15 items and accompanying recommendations were developed along with a user-friendly checklist. Conclusions: The introduction and use of the STROND checklist should lead to more consistent, transparent, and contextualized reporting of descriptive neuroepidemiologic studies resulting in more applicable and comparable findings and ultimately support better health care decisions.


Neurology | 2014

Autoimmune thyroiditis as a risk factor for stroke A historical cohort study

André Karch; Sara L Thomas

Objective: To investigate the effect of autoimmune thyroiditis (AIT) on risk of stroke and to assess whether any increased risk (1) varied by AIT duration, and (2) was independent of classic cardiovascular risk factors. Methods: This was a large historical cohort study using data from The Health Improvement Network Database. Rates of first stroke during follow-up in thyroxine-treated patients with AIT (n = 34,907) were compared with those in matched individuals without AIT (n = 149,632) using random-effects Poisson regression models. Results: There was strong evidence for a slightly increased risk of stroke in patients with AIT (adjusted rate ratio = 1.10, 95% confidence interval: 1.01–1.20). The observed increase was partly independent of cardiovascular risk factors. Higher effect sizes were identified in the first year after AIT diagnosis (rate ratio = 1.33, 95% confidence interval: 1.14–1.56) but not in the long-term, consistent with a residual effect of hypothyroidism. Conclusion: Our results support the hypothesis of a slightly increased risk of stroke in patients with AIT. The higher effect size found soon after AIT diagnosis suggests an increased cardiovascular risk due to thyroid-hormone deficiency rather than a cumulative effect of autoimmune pathology. Better screening and early treatment of patients with asymptomatic hypothyroid AIT could help reduce excess risk of stroke in the first year after diagnosis.


European Journal of Epidemiology | 2015

Development of the standards of reporting of neurological disorders (STROND) checklist: a guideline for the reporting of incidence and prevalence studies in neuroepidemiology

Derrick Bennett; Carol Brayne; Valery L. Feigin; Suzanne Barker-Collo; Michael Brainin; Daniel Davis; Valentina Gallo; N Jetté; André Karch; J F Kurtzke; Pablo M. Lavados; Giancarlo Logroscino; Gabriele Nagel; Preux P-M.; P M Rothwell; L W Svenson

Incidence and prevalence studies of neurological disorders play an important role in assessing the burden of disease and planning services. However, the assessment of disease estimates is hindered by problems in reporting for such studies. Despite a growth in published reports, existing guidelines relate to analytical rather than descriptive epidemiological studies. There are also no user-friendly tools (e.g., checklists) available for authors, editors and peer-reviewers to facilitate best practice in reporting of descriptive epidemiological studies for most neurological disorders. The Standards of Reporting of Neurological Disorders (STROND) is a guideline that consists of recommendations and a checklist to facilitate better reporting of published incidence and prevalence studies of neurological disorders. A review of previously developed guidance was used to produce a list of items required for incidence and prevalence studies in neurology. A three-round Delphi technique was used to identify the ‘basic minimum items’ important for reporting, as well as some additional ‘ideal reporting items’. An e-consultation process was then used in order to gauge opinion by external neuroepidemiological experts on the appropriateness of the items included in the checklist. Of 38 candidate items, 15 items and accompanying recommendations were developed along with a user-friendly checklist. The introduction and use of the STROND checklist should lead to more consistent, transparent and contextualised reporting of descriptive neuroepidemiological studies resulting in more applicable and comparable findings and ultimately support better healthcare decisions.


American Journal of Human Genetics | 2014

Ascertainment Bias Causes False Signal of Anticipation in Genetic Prion Disease

Eric Vallabh Minikel; Inga Zerr; Steven J. Collins; Claudia Ponto; Alison Boyd; Genevieve M. Klug; André Karch; Joanna Kenny; John Collinge; Leonel T. Takada; Sven Forner; Jamie Fong; Simon Mead; Michael D. Geschwind

Anticipation is the phenomenon whereby age of onset in genetic disease decreases in successive generations. Three independent reports have claimed anticipation in Creutzfeldt-Jakob disease (CJD) caused by the c.598G > A mutation in PRNP encoding a p.Glu200Lys (E200K) substitution in the prion protein. If confirmed, this finding would carry clear implications for genetic counseling. We analyzed pedigrees with this mutation from four prion centers worldwide (n = 217 individuals with the mutation) to analyze age of onset and death in affected and censored individuals. We show through simulation that selective ascertainment of individuals whose onset falls within the historical window since the mutations 1989 discovery is sufficient to create robust false signals both of anticipation and of heritability of age of onset. In our data set, the number of years of anticipation observed depends upon how strictly the data are limited by the ascertainment window. Among individuals whose disease was directly observed at a study center, a 28-year difference between parent and child age of onset is observed (p = 0.002), but including individuals ascertained retrospectively through family history reduces this figure to 7 years (p = 0.005). Applying survival analysis to the most thoroughly ascertained subset of data eliminates the signal of anticipation. Moreover, even non-CJD deaths exhibit 16 years anticipation (p = 0.002), indicating that ascertainment bias can entirely explain observed anticipation. We suggest that reports of anticipation in genetic prion disease are driven entirely by ascertainment bias. Guidelines for future studies claiming statistical evidence for anticipation are suggested.

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Inga Zerr

German Center for Neurodegenerative Diseases

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Matthias Schmitz

German Center for Neurodegenerative Diseases

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Jan Liman

University of Göttingen

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Mathias Bähr

University of Göttingen

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Franc Llorens

Instituto de Salud Carlos III

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Ilko L. Maier

University of Göttingen

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Michael Knauth

University of Göttingen

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Ewa Golanska

Medical University of Łódź

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