Wichtige epidemiologische Studientypen

Fall-Kontroll-Studien in der Arbeitsmedizin — ihre bedeutendsten Quellen für Verzerrung

Fall-Kontroll-Studien werden angewendet, um seltene Erkrankungen zu untersuchen. In der Arbeitsmedizin eignen sie sich besonders zur Untersuchung von Expositionen, die sich nicht einer bestimmten Industrie zuweisen lassen. Quellen der Verzerrung finden sich vor allem bei der Auswahl adaquater Kontrollen sowie bei einer differentiellen Missklassifikation der Exposition zwischen Fallen und Kontrollen. Sorgfaltige Planung, Durchfuhrung und Auswertung von Fall-Kontroll-Studien nach den Kriterien der Guten Epidemiologischen Praxis (GEP) kann Verzerrungen minimieren.

Effects of school-based interventions on motivation towards physical activity in children and adolescents: A systematic review and meta-analysis

Introduction Assuming that motivation is the key to initiate and sustain beneficial health behaviors, the aim of this systematic review was to analyze the effects of school-based physical activity interventions on a variety of motivational outcomes towards PA in school-aged children and adolescents. Methods A comprehensive literature search was carried out in six electronic databases to identify randomized controlled trials and quasi-experimental trials examining the effects of PA interventions implemented during the regular school day, e.g., during physical education lessons or lunch breaks. Primary outcomes of interest were students' motivation, basic psychological needs, goal orientation…

Stellungnahme der DGepi, gmds, DGSMP und DNEbM HPV-Impfung: Notwendigkeit der Begleitforschung und Evaluation

Invitation to cervical cancer screening does increase participation in Germany: Results from the MARZY study

The effect of different invitation models on participation in cervical cancer screening (CCS) was investigated in a randomized population-based cohort study in Germany. Participants were randomly selected via population registries and randomized into intervention Arm A (invitation letter) and Arm B (invitation letter and information brochure) or control Arm C (no invitation). The intervention and control arms were compared with regard to 3-year participation and the two invitation models were compared between intervention arms. Of the 7,758 eligible women aged 30-65 years, living in the city of Mainz and in the rural region of Mainz-Bingen, 5,265 were included in the analysis. Differences i…

A randomized trial comparing conventional cytology to liquid-based cytology and computer assistance.

Liquid-based cytology (LBC) has replaced conventional cytology (CC) for cervical cancer screening in some countries. However, it remains unclear whether LBC is superior to CC. A randomized controlled trial was conducted between August 2007 and March 2009 in Germany to compare LBC, alone and in combination with computer-assisted imaging technology (CAS), to CC in the detection of histologically confirmed cervical intraepithelial neoplasia (CIN). The main outcome measures were detection rates, relative sensitivities, positive predictive values (PPVs) and relative PPVs comparing LBC without and with CAS to CC. Primary histological outcome was CIN2 or higher. Included were 20,627 women particip…

Data Analysis of Epidemiological Studies

Epidemiology is used to describe the distribution of diseases in the population and to analyze the causes of these diseases. One important objective is to identify risk factors and to quantify their significance. A risk factor can influence the probability that a specific disease develops. Risk factors include: Environmental influences (for example, exposure to radon) Predisposition (for example, genes), or Behavioral characteristics (for example, hormone intake). Epidemiological research employs various different types of study (1–3), depending on the question asked. The most important are Cohort studies Case-control studies, and Cross-sectional studies In cohort studies, persons exposed t…

Screening for breast and cervical cancer in a large German city: participation, motivation and knowledge of risk factors.

Few data exist on attendance for cervical and breast cancer screening, breast self-examination and knowledge about risk factors for cervical cancer among German women. A population-based survey was performed in the city of Bielefeld in Germany.A questionnaire was mailed to 1500 randomly selected women age 25 to 75. Of those, 540 questionnaires were returned and 532 were analysed.Women participating in the survey considered themselves well informed about possibilities for early detection of breast cancer (84.0%). Most information was received from office-based gynaecologists (82.4%). 82.8% had a breast examination by a medical doctor annually and 43.1% practised breast self-examination every…

Vaccination against HPV-Associated Neoplasias

Neoplasias associated with anogenital human papilloma viruses (HPV) are characterised by high patient morbidity and mortality and by appreciable limitations in the patientʼs quality of life. Each year 530,000 women worldwide and 4800 women in Germany develop cervical cancer 1, 2. Biomolecular and epidemiological studies carried out in the past 25 years have demonstrated causal link between persisting infections with HPV 16 and HPV 18 and at least 11 other so-called high-risk HPVs (HR-HPVs) and the development of cervical cancer and its precursor lesions (so-called dysplasias or, respectively, cervical intraepithelial neoplasias – CIN). HPV 16, HPV 18 and other HR-HPVs are also the causes of…

Knowledge about infection with human papillomavirus: a systematic review.

Abstract Objective. Human papillomavirus (HPV) is a necessary cause of cervical cancer and genital warts. The aim of this systematic literature review was to provide an overview of knowledge about HPV infection among the public, students, patients and health professionals. Method. PubMed searches were performed and the results of studies were reported by age, gender, study population, country, recruitment score and year of study conduct. The recruitment score covered the mode of recruitment, study size and response rate. Results. We included 39 studies published between 1992 and 2006 covering a total of 19,986 participants. The proportion of participants who had heard of HPV varied from 13%…

Cervical Cancer Screening: Comparison of Conventional Pap Smear Test, Liquid-Based Cytology, and Human Papillomavirus Testing as Stand-alone or Cotesting Strategies

Abstract Background: Some countries have implemented stand-alone human papillomavirus (HPV) testing while others consider cotesting for cervical cancer screening. We compared both strategies within a population-based study. Methods: The MARZY cohort study was conducted in Germany. Randomly selected women from population registries aged ≥30 years (n = 5,275) were invited to screening with Pap smear, liquid-based cytology (LBC, ThinPrep), and HPV testing (Hybrid Capture2, HC2). Screen-positive participants [ASC-US+ or high-risk HC2 (hrHC2)] and a random 5% sample of screen-negatives were referred to colposcopy. Post hoc HPV genotyping was conducted by GP5+/6+ PCR-EIA with reverse line blottin…

TP53 codon 72 polymorphism and cervical cancer

Background Cervical cancer is caused primarily by human papillomaviruses (HPV). The polymorphism rs1042522 at codon 72 of the TP53 tumour-suppressor gene has been investigated as a genetic cofactor. More than 80 studies were done between 1998 and 2006, after it was initially reported that women who are homozygous for the arginine allele had a risk for cervical cancer seven times higher than women who were heterozygous for the allele. However, results have been inconsistent. Here we analyse pooled data from 49 studies to determine whether there is an association between TP53 codon 72 polymorphism and cervical cancer.Methods Individual data on 7946 cases and 7888 controls from 49 different st…

Evaluation of the methodological quality of articles on autologous breast reconstruction

Abstract Background Breast cancer remains the most common cancer among women worldwide. Autologous breast reconstruction may contribute toward restoring body image and improving quality of life after mastectomy. This systematic literature review describes differences in the quality and type of studies investigating autologous breast reconstruction techniques over time. Methods MEDLINE was searched for articles related to the surgical techniques, namely, TRAM, LADO, DIEP, and SGAP/IGAP, for the periods 1970 to 2007 and 2008 to 2010. The quality and type of studies were compared across the two time periods. Full-texts were evaluated according to prespecified quality criteria. Results The MEDL…

Prevalence of human papillomavirus types in women screened by cytology in Germany.

Incidence and mortality rates of cervical cancer are higher in Germany than in other Western European countries. Type-specific human papillomavirus (HPV) distribution was investigated for the first time in Germany in an epidemiological study including 8,101 women. Women above the age of 30 years, self-referring for cervical cancer screening, were enrolled in two study centers in Hannover (Northern Germany) and Tubingen (Southern Germany). Participants were screened by the Pap smear and the hybrid capture 2 (HC2) test using the high-risk probe. All samples that were positive by the HC2 test were genotyped using the prototype PGMY09/11 PCR line blot assay. Most women in the study population h…

976Screening for cervical cancer with Human Papillomavirus testing: stand-alone is preferable over co-testing with cytology

Abstract Background Cervical cancer screening can be conducted with cytology and Human Papillomavirus (HPV) testing but few studies have compared the latter directly to concomitant testing (co-testing). We compared these strategies to determine appropriate screening. Methods Within a randomised population-based cohort study conducted around Mainz, Germany, eligible women (≥30 years) were screened via Pap smear, liquid-based cytology (LBC) and HPV testing (HC2) and HPV genotyped post hoc (PCR). These tests formed three strategies: cytology (Pap or LBC) and HPV (HC2 or PCR) stand-alone and co-testing. Screen positives and 5% negative women were invited to colposcopy. Absolute and relative sen…

Comparison of the performance of different HPV genotyping methods for detecting genital HPV types

Classification of high-risk HPV types for cervical cancer screening depends on epidemiological studies defining HPV type-specific risk. The genotyping tests that are used, are however, not uniform with regard to type-specific detection rates making comparisons between different studies difficult. To overcome the lack of a “gold standard” four tests were evaluated crosswise using 824 cervical smears pretested by HC2. The tests evaluated were the L1-PCR-based assays PGMY09/11 LBA, HPV DNA Chip and SPF LiPA and an E1 consensus PCR followed by cycle sequencing (E1-PCR). A subset of 265 samples was tested in addition with the GP5+/6+ reverse line blot assay. Differences were noted in the sensiti…

Impfprävention HPV-assoziierter Neoplasien : Empfehlungen aus der aktuellen S3-Leitlinie des HPV-Management-Forums der Paul-Ehrlich-Gesellschaft für Chemotherapie e. V. – AWMF Leitlinien-Register Nr. 082-002 (Kurzfassung), gültig bis 31.12.2018

Influence of GSM signals on human peripheral lymphocytes: study of genotoxicity.

Exposure to radiofrequency (RF) electromagnetic fields (EMF) is continuously increasing worldwide. Yet, conflicting results of a possible genotoxic effect of RF EMF continue to be discussed. In the present study, a possible genotoxic effect of RF EMF (GSM, 1,800 MHz) in human lymphocytes was investigated by a collaboration of six independent institutes (institutes a, b, c, d, e, h). Peripheral blood of 20 healthy, nonsmoking volunteers of two age groups (10 volunteers 16-20 years old and 10 volunteers 50-65 years old) was taken, stimulated and intermittently exposed to three specific absorption rates (SARs) of RF EMF (0.2 W/kg, 2 W/kg, 10 W/kg) and sham for 28 h (institute a). The exposures…

Qualitätssicherung in einer epidemiologischen Kohortenstudie: Durchführung von on-site Monitoring in gynäkologischen Arztpraxen

Quality assurance is required for all relevant instruments and procedures in epidemiological studies just like for clinical trials. The structure and complexity of the monitoring was developed based on the monitoring in clinical trials and applied to an epidemiological cohort study on early detection of cervical cancer (MARZY Study). Analyses of the on-site monitoring in participating gynaecological practices during the baseline investigation of the MARZY cohort were presented. The baseline investigation of the MARZY study was conducted between 2005 and 2007 in the city of Mainz, the rural district of Mainz-Bingen and surrounding areas. Women, who were randomly selected via population regis…

Systematic Literature Reviews and Meta-Analyses

SUMMARY Background: Because of the rising number of scientific publications, it is important to have a means of jointly summarizing and assessing different studies on a single topic. Systematic literature reviews, meta-analyses of published data, and meta-analyses of individual data (pooled reanalyses) are now being published with increasing frequency. We here describe the essential features of these methods and discuss their strengths and weaknesses. Methods: This article is based on a selective literature search. The different types of review and meta-analysis are described, the methods used in each are outlined so that they can be evaluated, and a checklist is given for the assessment of…

Participation in cervical cancer screening in Germany.

Probability of hysterectomy in Germany

Introduction Hysterectomy is the most common gynecological surgery in many industrialized countries. In Germany, the hysterectomy rate is high in comparison to other European countries. The aim of this analysis was to determine the distribution of age at hysterectomy as well as the age-specific probability of undergoing a hysterectomy between the ages of 0–64 in the German female population. Methods Analyses were based on data from the MARZY study, a prospective, randomized, population-based cohort study investigating early detection of cervical cancer in western Germany. At baseline, 6429 women were invited to attend cervical cancer screening. The distribution of age at hysterectomy as wel…