Rafael Mikolajczyk | Hannover Medical School (original) (raw)

Papers by Rafael Mikolajczyk

Research paper thumbnail of Awareness and knowledge of sexually transmitted diseases (STDs) among school-going adolescents in Europe: a systematic review of published literature

BMC Public Health, 2011

Background: Sexually transmitted diseases (STDs) are a major health problem affecting mostly youn... more Background: Sexually transmitted diseases (STDs) are a major health problem affecting mostly young people, not only in developing, but also in developed countries. We conducted this systematic review to determine awareness and knowledge of school-going male and female adolescents in Europe of STDs and if possible, how they perceive their own risk of contracting an STD. Results of this review can help point out areas where STD risk communication for adolescents needs to be improved.

Research paper thumbnail of Normatives Feedback als Präventionskonzept bei Substanzkonsum – eine Übersicht

Das Gesundheitswesen, 2011

Research paper thumbnail of Social norms of polydrug use in Europe: Project Snipe

Research paper thumbnail of An Algorithm for Parameter Estimation in Nosocomial Infections

Mathematical Modeling of Biological Systems, Volume II, 2008

Page 1. 3 An Algorithm for Parameter Estimation in Nosocomial Infections Nico Stollenwerk1 and Ra... more Page 1. 3 An Algorithm for Parameter Estimation in Nosocomial Infections Nico Stollenwerk1 and Rafael Mikolajczyk2 ... J. Comp. Phys., 28, 395–407 (1978). 23. Feistel, R.: Betrachtung der Realisierung stochastischer Prozesse aus automatentheoretis-cher Sicht. Wiss. ...

Research paper thumbnail of Spousal Violence against Women and its Association with Women’s Mental Health in Pakistan

Health Care For Women International

Research paper thumbnail of Do university students support a ban on smoking in university buildings? A comparison of seven european countries

Background: Tobacco use is a major health risk behavior among young adults, including university ... more Background: Tobacco use is a major health risk behavior among young adults, including university students. Because smoking bans are effective in reducing cigarette consumption, we compare smoking behaviors in university students from seven European countries and their attitudes towards a ban on smoking at the university. Methods: The sample consists of 5,342 students from 7 universities in Bulgaria, Denmark, Germany, Lithuania, Poland, Spain, and Turkey. Students were asked about their smoking frequency in the last three months. All students were asked about their attitudes towards a ban on smoking in university buildings, using a four-point Likert scale ranging from fully agree to disagree with a ban. Results: Daily smoking ranged from 34% in Spain to 10% in Poland. In Denmark and Germany, there were little differences in daily smoking by gender. In the remaining countries, daily smoking was more common among males, with the exception of Bulgaria and Spain. In Bulgaria, 16% of male...

Research paper thumbnail of Estimations of worldwide prevalence of chronic hepatitis B virus infection: a systematic review of data published between 1965 and 2013

The Lancet, 2015

The quantification of the burden of disease attributable to hepatitis B virus (HBV) infection and... more The quantification of the burden of disease attributable to hepatitis B virus (HBV) infection and the adaptation of prevention and control measures requires knowledge on its prevalence in the general population. For most countries such data are not routinely available. We estimated the national, regional, and global prevalence of chronic HBV infection. For this systematic review and pooled analysis, we searched for data on prevalence of chronic HBV infection published between Jan 1, 1965, and Oct 23, 2013, in the databases Medline, Embase, CAB Abstracts (Global health), Popline, and Web of Science. We included studies reporting the hepatitis B surface antigen (HBsAg) serological marker of chronic HBV infection in non-high-risk groups and extracted data into a customised database. For each country, we calculated HBsAg prevalence estimates and 95% CIs weighted by study size. We extrapolated prevalence estimates to population sizes in 2010 to obtain the number of individuals with chronic HBV infection. Of the 17 029 records screened, 1800 report on the prevalence of HBsAg covering 161 countries were included. HBsAg seroprevalence was 3·61% (95% CI 3·61-3·61) worldwide with highest endemicity in countries of the African region (total 8·83%, 8·82-8·83) and Western Pacific region (total 5·26%, 5·26-5·26). Within WHO regions, prevalence ranged from 0·20% (0·19-0·21; Mexico) to 13·55% (9·00-19·89; Haiti) in the Americas, to 0·48% (0·12-1·90; the Seychelles) to 22·38% (20·10-24·83; South Sudan) in the African region. We estimated that in 2010, globally, about 248 million individuals were HBsAg positive. This first global assessment of country-level population prevalence of chronic HBV infection found a wide variation between countries and highlights the need for continued prevention and control strategies and the collection of reliable epidemiologic data using standardised methodology. World Health Organization.

Research paper thumbnail of Factors associated with low vaccination coverage among children in the Former Soviet countries: An example of Kyrgyzstan

Background Factors associated with low vaccination coverage were extensively investigated both in... more Background Factors associated with low vaccination coverage were extensively investigated both in developing and developed countries. It is not clear which factors affect vaccination coverage in former Soviet countries which experience intensive economic and health care system transition process. Methods We conducted a cross-sectional study among parents of first-year school children (n=934) from eight primary schools in the capital of, Bishkek in September 2006 using a self-administered questionnaire. The questionnaire included three major dimensions (parents’ attitudes towards vaccine safety and knowledge about vaccination, access to health care facilities and socio-demographic factors) which may have potential effects on vaccination coverage. Multilevel logistic regression analysis was conducted to identify factors independently associated with child’s vaccination status against hepatitis B and measles (in separate models) using PROC GLIMMIX in SAS 9.1.3. Results The coverage wit...

Research paper thumbnail of Klinische und experimentelle Untersuchungen zur Physiologie der Tuba Eustachii

Hno, 2009

Zusammenfassung Hintergrund Bei der Pathogenese chronisch-rezivierender Mittelohrentzündungen sp... more Zusammenfassung Hintergrund Bei der Pathogenese chronisch-rezivierender Mittelohrentzündungen spielt die Physiologie der Tuba Eustachii eine wesentliche Rolle. Wir haben ein Tiermodell etabliert, mit dem der Einfluss des extraösophagealen Reflux (EÖR) auf die Tubenfunktion untersucht werden kann. Wir konnten zeigen, dass EÖR über die Tube in das Mittelohr gelangen kann. Daher könnte EÖR ein pathogenetischer Faktor für eine gestörte Tubenfunktion sein. Neben bislang

Research paper thumbnail of Mortality in the German Pharmacoepidemiological Research Database (GePaRD) compared to national data in Germany: results from a validation study

BMC Public Health, 2015

Background: Electronic healthcare databases are of increasing importance in health research and m... more Background: 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. Methods: The study population comprised insurants of four statutory health insurances providing data for GePaRD with either continuous insurance coverage from January 1 st to December 31 st 2006 or until death. The sex-specific mortality rate, stratified and standardized by age, and the percentage of hospital deaths among all deaths was compared with data from the FSOG. Furthermore, the agreement between the dates of death according to hospital data and core data was assessed within GePaRD. Results: The study population comprised 12,033,622 insurants. Compared to FSOG data, the age-standardised mortality rate in GePaRD was 21 % and 29 % lower in women and men, respectively. Regional analyses also indicated lower mortality rates in all federal states except for Bremen, where the age-standardised mortality rate was similar to FSOG data for both sexes. The percentage of hospital deaths among all deaths corresponded well with external data. The proportion of inpatient deaths also recorded in the health insurance core data was 98.5 %. Furthermore, 94 % of dates of death documented in hospital agreed with the dates of death according to the health insurance core data. Conclusions: The lower mortality rates in almost all federal states might result from the higher socioeconomic status of the GePaRD study population compared to the overall population in Germany. In the federal state of Bremen, where socioeconomic representativeness is higher due to additional inclusion of two local health insurances, the mortality rates were in good accordance with external data. Agreement of the percentage of hospital deaths among all deaths between GePaRD and national statistics suggested completeness of outpatient mortality information.

Research paper thumbnail of What is the optimal rate of caesarean section at population level? A systematic review of ecologic studies

Reproductive Health, 2015

In 1985, WHO stated that there was no justification for caesarean section (CS) rates higher than ... more In 1985, WHO stated that there was no justification for caesarean section (CS) rates higher than 10-15 % at population-level. While the CS rates worldwide have continued to increase in an unprecedented manner over the subsequent three decades, concern has been raised about the validity of the 1985 landmark statement. We conducted a systematic review to identify, critically appraise and synthesize the analyses of the ecologic association between CS rates and maternal, neonatal and infant outcomes. Four electronic databases were searched for ecologic studies published between 2000 and 2014 that analysed the possible association between CS rates and maternal, neonatal or infant mortality or morbidity. Two reviewers performed study selection, data extraction and quality assessment independently. We identified 11,832 unique citations and eight studies were included in the review. Seven studies correlated CS rates with maternal mortality, five with neonatal mortality, four with infant mortality, two with LBW and one with stillbirths. Except for one, all studies were cross-sectional in design and five were global analyses of national-level CS rates versus mortality outcomes. Although the overall quality of the studies was acceptable; only two studies controlled for socio-economic factors and none controlled for clinical or demographic characteristics of the population. In unadjusted analyses, authors found a strong inverse relationship between CS rates and the mortality outcomes so that maternal, neonatal and infant mortality decrease as CS rates increase up to a certain threshold. In the eight studies included in this review, this threshold was at CS rates between 9 and 16 %. However, in the two studies that adjusted for socio-economic factors, this relationship was either weakened or disappeared after controlling for these confounders. CS rates above the threshold of 9-16 % were not associated with decreases in mortality outcomes regardless of adjustments. Our findings could be interpreted to mean that at CS rates below this threshold, socio-economic development may be driving the ecologic association between CS rates and mortality. On the other hand, at rates higher than this threshold, there is no association between CS and mortality outcomes regardless of adjustment. The ecological association between CS rates and relevant morbidity outcomes needs to be evaluated before drawing more definite conclusions at population level.

Research paper thumbnail of Systematic review of models assessing the economic value of routine varicella and herpes zoster vaccination in high-income countries

BMC Public Health, 2015

Background: A systematic review was conducted to assess the cost-effectiveness of routine varicel... more Background: A systematic review was conducted to assess the cost-effectiveness of routine varicella and herpes zoster (HZ) vaccination in high-income countries estimated by modelling studies. Methods: A PubMed search was performed to identify relevant studies published before October 2013. Studies were included in the review if they (i) evaluated the cost-effectiveness of routine childhood or adolescent varicella vaccination and/or HZ vaccination targeting the elderly, and if they (ii) reported results for high-income countries. Results: A total of 38 model-based studies were identified that fulfilled the inclusion criteria. Routine childhood or adolescent varicella vaccination was cost-effective or cost-saving from a payer perspective and always cost-saving from a societal perspective when ignoring its potential impact on HZ incidence due to reduced or absent exogenous boosting. The inclusion of the potential impact of childhood varicella vaccination on HZ led to net quality-adjusted life-year (QALY) losses or incremental cost-effectiveness ratios exceeding commonly accepted thresholds. Additional HZ vaccination could partially mitigate this effect. Studies focusing only on the evaluation of HZ vaccination reported a wide range of results depending on the selected target age-group and the vaccine price, but most found HZ vaccination to be a cost-effective or marginally cost-effective intervention. Cost-effectiveness of HZ vaccination was strongly dependent on the age at vaccination, the price of the vaccine, the assumed duration of protection and the applied cost per QALY threshold. Conclusions: While HZ vaccination is mostly considered cost-effective, cost-effectiveness of varicella vaccination primarily depends on the in-or exclusion of exogenous boosting in the model. As a consequence, clarification on the role of exogenous boosting is crucial for decision-making regarding varicella vaccination. Ultsch et al. [39] 50 No vaccination EUR 37,173/QALY; EUR 1,587/HZ case avoided; EUR 32,545/PHN case avoided EUR 30,901/QALY; EUR 1,320/HZ case avoided; EUR 27,054/PHN case avoided 55 No vaccination EUR 32,480/QALY; EUR 1,518/HZ case avoided; EUR 26,194/PHN case avoided EUR 28,244/QALY; EUR 1,320/HZ case avoided; EUR 22,777/PHN case avoided 60 No vaccination EUR 30,212/QALY; EUR 1,525/HZ case avoided; EUR 22,337/PHN case avoided EUR 28,146/QALY; EUR 1,419/HZ case avoided; EUR 20,809/PHN case avoided 65 No vaccination EUR 30,807/QALY; EUR 1,655/HZ case avoided; EUR 20,951/PHN case avoided EUR 29,526/QALY; EUR 1,586/HZ case avoided; EUR 20,079/PHN case avoided 70 No vaccination EUR 42,190/QALY; EUR 2,732/HZ case avoided; EUR 22,813/PHN case avoided EUR 41,942/QALY; EUR 2,716/HZ case avoided; EUR 22,679/PHN case avoided 75 No vaccination EUR 55,171/QALY; EUR 3,939/HZ case avoided; EUR 27,396/PHN case avoided EUR 54,940/QALY; EUR 3,923/HZ case avoided; EUR 27,281/PHN case avoided 80 No vaccination EUR 92,734/QALY; EUR 9,433/HZ case avoided; EUR 35,717/PHN case avoided EUR 92,541/QALY; EUR 9,414/HZ case avoided; EUR 35,643/PHN case avoided

Research paper thumbnail of Methods and Concepts of Epidemiology

Statistics for Biology and Health, 2009

The purpose of this chapter is to review the basic concepts of epidemiology, including definition... more The purpose of this chapter is to review the basic concepts of epidemiology, including definitions of measures of disease occurrence and measures of association, brief descriptions of study designs and ethical principles of epidemiological research. Additionally, the theory and criteria of causation, systematic and random errors in epidemiological studies and methodological issues related to diagnostic tests are discussed. The concepts

Research paper thumbnail of Verknüpfung von Routinedaten der Gesetzlichen Krankenversicherung mit Daten eines Krankenhausinformationssystems: Machbar, aber auch „nützlich“?

Das Gesundheitswesen, 2015

Aim: Administrative data are increasingly being linked with other data sources for research purpo... more Aim: Administrative data are increasingly being linked with other data sources for research purposes in the field of epidemiology and health services research abroad. In Germany, the direct linkage of routine data of statutory health insurance (SHI) providers with other data sources is complicated due to strict data protection requirements. The aim of this analysis was to evaluate an indirect linkage of SHI routine data with data of a hospital information system (HIS). Methods: The dataset comprised data from 2004 to 2010 from 2 sickness funds and one HIS. In both data sources, hospitalisations were restricted to admissions into one hospital with at least one diagnosis of heart failure. The 2 data sources were linked, in cases of the agreement of the admission and discharge dates, as well as the agreement of at least a certain percentage of diagnoses in HIS data when compared to SHI data (full coding depth). Based on the direct linkage using the pseudonymised insurance number as gold standard, the proposed linkage approach was evaluated by means of test statistics. Furthermore, the completeness of relevant information of the HIS was described. Results: The dataset contained 3 731 hospitalisations from the HIS and 8 172 hospitalisations from the SHI routine data. The sensitivity of the linkage approach was 86.7% in the case of an agreement of at least 30% of the diagnoses and decreased to 41.7% in the case of 100% agreement in the diagnoses. The specificity was almost 100% at all studied cut-offs of agreement. Anthropometric measures and diagnostic information were available only for a small fraction of cases in the data of the HIS, whereas information on the health status and on laboratory information was comparatively complete. Conclusion: For the linkage of SHI routine data with complementary data sources, indirect linkage methods can be a valuable alternative in comparison to direct linkage, which is time-consuming with regard to planning and application. Since the proposed approach was used in a relatively small sample and a restricted patient population, a replication using nation-wide data without respective restrictions would require an extension of the algorithm. Furthermore, the large administrative effort seems questionable considering the comparatively high amount of missing values in interesting information in the HIS.

Research paper thumbnail of Personal and Perceived Peer Use of and Attitudes Toward Alcohol Among University and College Students in Seven EU Countries: Project SNIPE

Journal of Studies on Alcohol and Drugs, 2015

Objective: The objective of this study was to explore perceptions of peer substance use and relat... more Objective: The objective of this study was to explore perceptions of peer substance use and related attitudes among European students. Challenging perceptions about peer substance use has become the basis of a form of prevention and intervention known as the social norms approach, which can be delivered using personalized online feedback. This article reports baseline alcohol use and attitudes data for university students across Europe collected as part of the Social Norms Intervention for the prevention of Polydrug usE project (Project SNIPE). Method: Students from universities in Belgium, Denmark, Germany, the Slovak Republic, Spain, Turkey, and the United Kingdom were recruited to take part in an online survey by the use of email invitations, social media, classroom announcements, flyers, and stalls in social areas, such as in cafeterias and bars on campus. A total of 4,482 students agreed to participate. Results: Overall, respondents reported both perceived alcohol use and perceived acceptance of alcohol use among their peers that were higher than their own use or acceptance. Perceived peers' behaviors and attitudes were found to be predictive of personal behaviors and attitudes, with some variation across countries and by sex.

Research paper thumbnail of Infektionen im Kindesalter

Public Health Forum, 2014

ABSTRACT Infancy and early childhood represent the most sensitive period of life with respect to ... more ABSTRACT Infancy and early childhood represent the most sensitive period of life with respect to both, development of the immune system and exposure to infectious diseases. Therefore, numerous efforts have been and are being taken to study the associations between infections, immune response and long-term outcomes. New findings are expected from birth cohorts dedicated to infection research.

Research paper thumbnail of Wer fördert Public Health Forschungsprojekte international?

Public Health Forum, 2006

Research paper thumbnail of Drogenkonsum von Studierenden – Ergebnisse des Gesundheitssurveys NRW

Public Health Forum, 2010

Research paper thumbnail of Contact profiles in eight European countries and implications for modelling the spread of airborne infectious diseases

PloS one, 2009

For understanding the spread of infectious diseases it is crucial to have knowledge of the patter... more For understanding the spread of infectious diseases it is crucial to have knowledge of the patterns of contacts in a population during which the infection can be transmitted. Besides contact rates and mixing between age groups, the way individuals distribute their contacts across different locations may play an important role in determining how infections spread through a population. Representative surveys were performed in eight countries to assess the number of social contacts (talking to another person at close distance either with or without physical contact), using a diary approach in which participants recorded individual contacts. The overall sample size was 7290 respondents. We analyzed the reported numbers of contacts per respondent in six different settings (household, work, school, leisure, transportation and others) to define different contact profiles. The identification of the profiles and classification of respondents according to these profiles was conducted using a ...

Research paper thumbnail of 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

Clinical research in cardiology : official journal of the German Cardiac Society, Jan 17, 2015

Heart failure (HF) continues to be a leading cause of morbidity and mortality in industrialized c... more 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. The study was based on data for the years 2004-2006 from three German statutory health insurance providers, comprising data of more than six million people. The study sample was not restricted to a specific age group. The incidence rate of HF in 2006 was assessed in patients who did not have a diagnosis of HF or had not received medications for HF in the previous 2 years. One-year all-cause mortality in patients who received their first diagnosis of HF in hospital was analysed using Kaplan-Meier method and Cox proportional hazard model. Case identification was based on confirmed outpatient di...

Research paper thumbnail of Awareness and knowledge of sexually transmitted diseases (STDs) among school-going adolescents in Europe: a systematic review of published literature

BMC Public Health, 2011

Background: Sexually transmitted diseases (STDs) are a major health problem affecting mostly youn... more Background: Sexually transmitted diseases (STDs) are a major health problem affecting mostly young people, not only in developing, but also in developed countries. We conducted this systematic review to determine awareness and knowledge of school-going male and female adolescents in Europe of STDs and if possible, how they perceive their own risk of contracting an STD. Results of this review can help point out areas where STD risk communication for adolescents needs to be improved.

Research paper thumbnail of Normatives Feedback als Präventionskonzept bei Substanzkonsum – eine Übersicht

Das Gesundheitswesen, 2011

Research paper thumbnail of Social norms of polydrug use in Europe: Project Snipe

Research paper thumbnail of An Algorithm for Parameter Estimation in Nosocomial Infections

Mathematical Modeling of Biological Systems, Volume II, 2008

Page 1. 3 An Algorithm for Parameter Estimation in Nosocomial Infections Nico Stollenwerk1 and Ra... more Page 1. 3 An Algorithm for Parameter Estimation in Nosocomial Infections Nico Stollenwerk1 and Rafael Mikolajczyk2 ... J. Comp. Phys., 28, 395–407 (1978). 23. Feistel, R.: Betrachtung der Realisierung stochastischer Prozesse aus automatentheoretis-cher Sicht. Wiss. ...

Research paper thumbnail of Spousal Violence against Women and its Association with Women’s Mental Health in Pakistan

Health Care For Women International

Research paper thumbnail of Do university students support a ban on smoking in university buildings? A comparison of seven european countries

Background: Tobacco use is a major health risk behavior among young adults, including university ... more Background: Tobacco use is a major health risk behavior among young adults, including university students. Because smoking bans are effective in reducing cigarette consumption, we compare smoking behaviors in university students from seven European countries and their attitudes towards a ban on smoking at the university. Methods: The sample consists of 5,342 students from 7 universities in Bulgaria, Denmark, Germany, Lithuania, Poland, Spain, and Turkey. Students were asked about their smoking frequency in the last three months. All students were asked about their attitudes towards a ban on smoking in university buildings, using a four-point Likert scale ranging from fully agree to disagree with a ban. Results: Daily smoking ranged from 34% in Spain to 10% in Poland. In Denmark and Germany, there were little differences in daily smoking by gender. In the remaining countries, daily smoking was more common among males, with the exception of Bulgaria and Spain. In Bulgaria, 16% of male...

Research paper thumbnail of Estimations of worldwide prevalence of chronic hepatitis B virus infection: a systematic review of data published between 1965 and 2013

The Lancet, 2015

The quantification of the burden of disease attributable to hepatitis B virus (HBV) infection and... more The quantification of the burden of disease attributable to hepatitis B virus (HBV) infection and the adaptation of prevention and control measures requires knowledge on its prevalence in the general population. For most countries such data are not routinely available. We estimated the national, regional, and global prevalence of chronic HBV infection. For this systematic review and pooled analysis, we searched for data on prevalence of chronic HBV infection published between Jan 1, 1965, and Oct 23, 2013, in the databases Medline, Embase, CAB Abstracts (Global health), Popline, and Web of Science. We included studies reporting the hepatitis B surface antigen (HBsAg) serological marker of chronic HBV infection in non-high-risk groups and extracted data into a customised database. For each country, we calculated HBsAg prevalence estimates and 95% CIs weighted by study size. We extrapolated prevalence estimates to population sizes in 2010 to obtain the number of individuals with chronic HBV infection. Of the 17 029 records screened, 1800 report on the prevalence of HBsAg covering 161 countries were included. HBsAg seroprevalence was 3·61% (95% CI 3·61-3·61) worldwide with highest endemicity in countries of the African region (total 8·83%, 8·82-8·83) and Western Pacific region (total 5·26%, 5·26-5·26). Within WHO regions, prevalence ranged from 0·20% (0·19-0·21; Mexico) to 13·55% (9·00-19·89; Haiti) in the Americas, to 0·48% (0·12-1·90; the Seychelles) to 22·38% (20·10-24·83; South Sudan) in the African region. We estimated that in 2010, globally, about 248 million individuals were HBsAg positive. This first global assessment of country-level population prevalence of chronic HBV infection found a wide variation between countries and highlights the need for continued prevention and control strategies and the collection of reliable epidemiologic data using standardised methodology. World Health Organization.

Research paper thumbnail of Factors associated with low vaccination coverage among children in the Former Soviet countries: An example of Kyrgyzstan

Background Factors associated with low vaccination coverage were extensively investigated both in... more Background Factors associated with low vaccination coverage were extensively investigated both in developing and developed countries. It is not clear which factors affect vaccination coverage in former Soviet countries which experience intensive economic and health care system transition process. Methods We conducted a cross-sectional study among parents of first-year school children (n=934) from eight primary schools in the capital of, Bishkek in September 2006 using a self-administered questionnaire. The questionnaire included three major dimensions (parents’ attitudes towards vaccine safety and knowledge about vaccination, access to health care facilities and socio-demographic factors) which may have potential effects on vaccination coverage. Multilevel logistic regression analysis was conducted to identify factors independently associated with child’s vaccination status against hepatitis B and measles (in separate models) using PROC GLIMMIX in SAS 9.1.3. Results The coverage wit...

Research paper thumbnail of Klinische und experimentelle Untersuchungen zur Physiologie der Tuba Eustachii

Hno, 2009

Zusammenfassung Hintergrund Bei der Pathogenese chronisch-rezivierender Mittelohrentzündungen sp... more Zusammenfassung Hintergrund Bei der Pathogenese chronisch-rezivierender Mittelohrentzündungen spielt die Physiologie der Tuba Eustachii eine wesentliche Rolle. Wir haben ein Tiermodell etabliert, mit dem der Einfluss des extraösophagealen Reflux (EÖR) auf die Tubenfunktion untersucht werden kann. Wir konnten zeigen, dass EÖR über die Tube in das Mittelohr gelangen kann. Daher könnte EÖR ein pathogenetischer Faktor für eine gestörte Tubenfunktion sein. Neben bislang

Research paper thumbnail of Mortality in the German Pharmacoepidemiological Research Database (GePaRD) compared to national data in Germany: results from a validation study

BMC Public Health, 2015

Background: Electronic healthcare databases are of increasing importance in health research and m... more Background: 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. Methods: The study population comprised insurants of four statutory health insurances providing data for GePaRD with either continuous insurance coverage from January 1 st to December 31 st 2006 or until death. The sex-specific mortality rate, stratified and standardized by age, and the percentage of hospital deaths among all deaths was compared with data from the FSOG. Furthermore, the agreement between the dates of death according to hospital data and core data was assessed within GePaRD. Results: The study population comprised 12,033,622 insurants. Compared to FSOG data, the age-standardised mortality rate in GePaRD was 21 % and 29 % lower in women and men, respectively. Regional analyses also indicated lower mortality rates in all federal states except for Bremen, where the age-standardised mortality rate was similar to FSOG data for both sexes. The percentage of hospital deaths among all deaths corresponded well with external data. The proportion of inpatient deaths also recorded in the health insurance core data was 98.5 %. Furthermore, 94 % of dates of death documented in hospital agreed with the dates of death according to the health insurance core data. Conclusions: The lower mortality rates in almost all federal states might result from the higher socioeconomic status of the GePaRD study population compared to the overall population in Germany. In the federal state of Bremen, where socioeconomic representativeness is higher due to additional inclusion of two local health insurances, the mortality rates were in good accordance with external data. Agreement of the percentage of hospital deaths among all deaths between GePaRD and national statistics suggested completeness of outpatient mortality information.

Research paper thumbnail of What is the optimal rate of caesarean section at population level? A systematic review of ecologic studies

Reproductive Health, 2015

In 1985, WHO stated that there was no justification for caesarean section (CS) rates higher than ... more In 1985, WHO stated that there was no justification for caesarean section (CS) rates higher than 10-15 % at population-level. While the CS rates worldwide have continued to increase in an unprecedented manner over the subsequent three decades, concern has been raised about the validity of the 1985 landmark statement. We conducted a systematic review to identify, critically appraise and synthesize the analyses of the ecologic association between CS rates and maternal, neonatal and infant outcomes. Four electronic databases were searched for ecologic studies published between 2000 and 2014 that analysed the possible association between CS rates and maternal, neonatal or infant mortality or morbidity. Two reviewers performed study selection, data extraction and quality assessment independently. We identified 11,832 unique citations and eight studies were included in the review. Seven studies correlated CS rates with maternal mortality, five with neonatal mortality, four with infant mortality, two with LBW and one with stillbirths. Except for one, all studies were cross-sectional in design and five were global analyses of national-level CS rates versus mortality outcomes. Although the overall quality of the studies was acceptable; only two studies controlled for socio-economic factors and none controlled for clinical or demographic characteristics of the population. In unadjusted analyses, authors found a strong inverse relationship between CS rates and the mortality outcomes so that maternal, neonatal and infant mortality decrease as CS rates increase up to a certain threshold. In the eight studies included in this review, this threshold was at CS rates between 9 and 16 %. However, in the two studies that adjusted for socio-economic factors, this relationship was either weakened or disappeared after controlling for these confounders. CS rates above the threshold of 9-16 % were not associated with decreases in mortality outcomes regardless of adjustments. Our findings could be interpreted to mean that at CS rates below this threshold, socio-economic development may be driving the ecologic association between CS rates and mortality. On the other hand, at rates higher than this threshold, there is no association between CS and mortality outcomes regardless of adjustment. The ecological association between CS rates and relevant morbidity outcomes needs to be evaluated before drawing more definite conclusions at population level.

Research paper thumbnail of Systematic review of models assessing the economic value of routine varicella and herpes zoster vaccination in high-income countries

BMC Public Health, 2015

Background: A systematic review was conducted to assess the cost-effectiveness of routine varicel... more Background: A systematic review was conducted to assess the cost-effectiveness of routine varicella and herpes zoster (HZ) vaccination in high-income countries estimated by modelling studies. Methods: A PubMed search was performed to identify relevant studies published before October 2013. Studies were included in the review if they (i) evaluated the cost-effectiveness of routine childhood or adolescent varicella vaccination and/or HZ vaccination targeting the elderly, and if they (ii) reported results for high-income countries. Results: A total of 38 model-based studies were identified that fulfilled the inclusion criteria. Routine childhood or adolescent varicella vaccination was cost-effective or cost-saving from a payer perspective and always cost-saving from a societal perspective when ignoring its potential impact on HZ incidence due to reduced or absent exogenous boosting. The inclusion of the potential impact of childhood varicella vaccination on HZ led to net quality-adjusted life-year (QALY) losses or incremental cost-effectiveness ratios exceeding commonly accepted thresholds. Additional HZ vaccination could partially mitigate this effect. Studies focusing only on the evaluation of HZ vaccination reported a wide range of results depending on the selected target age-group and the vaccine price, but most found HZ vaccination to be a cost-effective or marginally cost-effective intervention. Cost-effectiveness of HZ vaccination was strongly dependent on the age at vaccination, the price of the vaccine, the assumed duration of protection and the applied cost per QALY threshold. Conclusions: While HZ vaccination is mostly considered cost-effective, cost-effectiveness of varicella vaccination primarily depends on the in-or exclusion of exogenous boosting in the model. As a consequence, clarification on the role of exogenous boosting is crucial for decision-making regarding varicella vaccination. Ultsch et al. [39] 50 No vaccination EUR 37,173/QALY; EUR 1,587/HZ case avoided; EUR 32,545/PHN case avoided EUR 30,901/QALY; EUR 1,320/HZ case avoided; EUR 27,054/PHN case avoided 55 No vaccination EUR 32,480/QALY; EUR 1,518/HZ case avoided; EUR 26,194/PHN case avoided EUR 28,244/QALY; EUR 1,320/HZ case avoided; EUR 22,777/PHN case avoided 60 No vaccination EUR 30,212/QALY; EUR 1,525/HZ case avoided; EUR 22,337/PHN case avoided EUR 28,146/QALY; EUR 1,419/HZ case avoided; EUR 20,809/PHN case avoided 65 No vaccination EUR 30,807/QALY; EUR 1,655/HZ case avoided; EUR 20,951/PHN case avoided EUR 29,526/QALY; EUR 1,586/HZ case avoided; EUR 20,079/PHN case avoided 70 No vaccination EUR 42,190/QALY; EUR 2,732/HZ case avoided; EUR 22,813/PHN case avoided EUR 41,942/QALY; EUR 2,716/HZ case avoided; EUR 22,679/PHN case avoided 75 No vaccination EUR 55,171/QALY; EUR 3,939/HZ case avoided; EUR 27,396/PHN case avoided EUR 54,940/QALY; EUR 3,923/HZ case avoided; EUR 27,281/PHN case avoided 80 No vaccination EUR 92,734/QALY; EUR 9,433/HZ case avoided; EUR 35,717/PHN case avoided EUR 92,541/QALY; EUR 9,414/HZ case avoided; EUR 35,643/PHN case avoided

Research paper thumbnail of Methods and Concepts of Epidemiology

Statistics for Biology and Health, 2009

The purpose of this chapter is to review the basic concepts of epidemiology, including definition... more The purpose of this chapter is to review the basic concepts of epidemiology, including definitions of measures of disease occurrence and measures of association, brief descriptions of study designs and ethical principles of epidemiological research. Additionally, the theory and criteria of causation, systematic and random errors in epidemiological studies and methodological issues related to diagnostic tests are discussed. The concepts

Research paper thumbnail of Verknüpfung von Routinedaten der Gesetzlichen Krankenversicherung mit Daten eines Krankenhausinformationssystems: Machbar, aber auch „nützlich“?

Das Gesundheitswesen, 2015

Aim: Administrative data are increasingly being linked with other data sources for research purpo... more Aim: Administrative data are increasingly being linked with other data sources for research purposes in the field of epidemiology and health services research abroad. In Germany, the direct linkage of routine data of statutory health insurance (SHI) providers with other data sources is complicated due to strict data protection requirements. The aim of this analysis was to evaluate an indirect linkage of SHI routine data with data of a hospital information system (HIS). Methods: The dataset comprised data from 2004 to 2010 from 2 sickness funds and one HIS. In both data sources, hospitalisations were restricted to admissions into one hospital with at least one diagnosis of heart failure. The 2 data sources were linked, in cases of the agreement of the admission and discharge dates, as well as the agreement of at least a certain percentage of diagnoses in HIS data when compared to SHI data (full coding depth). Based on the direct linkage using the pseudonymised insurance number as gold standard, the proposed linkage approach was evaluated by means of test statistics. Furthermore, the completeness of relevant information of the HIS was described. Results: The dataset contained 3 731 hospitalisations from the HIS and 8 172 hospitalisations from the SHI routine data. The sensitivity of the linkage approach was 86.7% in the case of an agreement of at least 30% of the diagnoses and decreased to 41.7% in the case of 100% agreement in the diagnoses. The specificity was almost 100% at all studied cut-offs of agreement. Anthropometric measures and diagnostic information were available only for a small fraction of cases in the data of the HIS, whereas information on the health status and on laboratory information was comparatively complete. Conclusion: For the linkage of SHI routine data with complementary data sources, indirect linkage methods can be a valuable alternative in comparison to direct linkage, which is time-consuming with regard to planning and application. Since the proposed approach was used in a relatively small sample and a restricted patient population, a replication using nation-wide data without respective restrictions would require an extension of the algorithm. Furthermore, the large administrative effort seems questionable considering the comparatively high amount of missing values in interesting information in the HIS.

Research paper thumbnail of Personal and Perceived Peer Use of and Attitudes Toward Alcohol Among University and College Students in Seven EU Countries: Project SNIPE

Journal of Studies on Alcohol and Drugs, 2015

Objective: The objective of this study was to explore perceptions of peer substance use and relat... more Objective: The objective of this study was to explore perceptions of peer substance use and related attitudes among European students. Challenging perceptions about peer substance use has become the basis of a form of prevention and intervention known as the social norms approach, which can be delivered using personalized online feedback. This article reports baseline alcohol use and attitudes data for university students across Europe collected as part of the Social Norms Intervention for the prevention of Polydrug usE project (Project SNIPE). Method: Students from universities in Belgium, Denmark, Germany, the Slovak Republic, Spain, Turkey, and the United Kingdom were recruited to take part in an online survey by the use of email invitations, social media, classroom announcements, flyers, and stalls in social areas, such as in cafeterias and bars on campus. A total of 4,482 students agreed to participate. Results: Overall, respondents reported both perceived alcohol use and perceived acceptance of alcohol use among their peers that were higher than their own use or acceptance. Perceived peers' behaviors and attitudes were found to be predictive of personal behaviors and attitudes, with some variation across countries and by sex.

Research paper thumbnail of Infektionen im Kindesalter

Public Health Forum, 2014

ABSTRACT Infancy and early childhood represent the most sensitive period of life with respect to ... more ABSTRACT Infancy and early childhood represent the most sensitive period of life with respect to both, development of the immune system and exposure to infectious diseases. Therefore, numerous efforts have been and are being taken to study the associations between infections, immune response and long-term outcomes. New findings are expected from birth cohorts dedicated to infection research.

Research paper thumbnail of Wer fördert Public Health Forschungsprojekte international?

Public Health Forum, 2006

Research paper thumbnail of Drogenkonsum von Studierenden – Ergebnisse des Gesundheitssurveys NRW

Public Health Forum, 2010

Research paper thumbnail of Contact profiles in eight European countries and implications for modelling the spread of airborne infectious diseases

PloS one, 2009

For understanding the spread of infectious diseases it is crucial to have knowledge of the patter... more For understanding the spread of infectious diseases it is crucial to have knowledge of the patterns of contacts in a population during which the infection can be transmitted. Besides contact rates and mixing between age groups, the way individuals distribute their contacts across different locations may play an important role in determining how infections spread through a population. Representative surveys were performed in eight countries to assess the number of social contacts (talking to another person at close distance either with or without physical contact), using a diary approach in which participants recorded individual contacts. The overall sample size was 7290 respondents. We analyzed the reported numbers of contacts per respondent in six different settings (household, work, school, leisure, transportation and others) to define different contact profiles. The identification of the profiles and classification of respondents according to these profiles was conducted using a ...

Research paper thumbnail of 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

Clinical research in cardiology : official journal of the German Cardiac Society, Jan 17, 2015

Heart failure (HF) continues to be a leading cause of morbidity and mortality in industrialized c... more 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. The study was based on data for the years 2004-2006 from three German statutory health insurance providers, comprising data of more than six million people. The study sample was not restricted to a specific age group. The incidence rate of HF in 2006 was assessed in patients who did not have a diagnosis of HF or had not received medications for HF in the previous 2 years. One-year all-cause mortality in patients who received their first diagnosis of HF in hospital was analysed using Kaplan-Meier method and Cox proportional hazard model. Case identification was based on confirmed outpatient di...