Study Designs in Genetic Epidemiology

Author(s):  
Michele L. Cote
2019 ◽  
Vol 188 (12) ◽  
pp. 2069-2077
Author(s):  
Priya Duggal ◽  
Christine Ladd-Acosta ◽  
Debashree Ray ◽  
Terri H Beaty

Abstract The field of genetic epidemiology is relatively young and brings together genetics, epidemiology, and biostatistics to identify and implement the best study designs and statistical analyses for identifying genes controlling risk for complex and heterogeneous diseases (i.e., those where genes and environmental risk factors both contribute to etiology). The field has moved quickly over the past 40 years partly because the technology of genotyping and sequencing has forced it to adapt while adhering to the fundamental principles of genetics. In the last two decades, the available tools for genetic epidemiology have expanded from a genetic focus (considering 1 gene at a time) to a genomic focus (considering the entire genome), and now they must further expand to integrate information from other “-omics” (e.g., epigenomics, transcriptomics as measured by RNA expression) at both the individual and the population levels. Additionally, we can now also evaluate gene and environment interactions across populations to better understand exposure and the heterogeneity in disease risk. The future challenges facing genetic epidemiology are considerable both in scale and techniques, but the importance of the field will not diminish because by design it ties scientific goals with public health applications.


Author(s):  
Frühling Rijsdijk ◽  
Paul F. O’Reilly

This chapter demonstrates the principles behind some of the major genetic study designs used in psychiatry research. The first part focuses on behavioural genetic designs, while the second part describes designs for ‘gene mapping’. Behavioural genetics examines the genetic basis of behavioural phenotypes, including both disorders and ‘normal’ dimensional traits. The theoretical basis is derived from population genetics, including properties such as segregation ratios, random mating, genetic variance, and genetic correlation between relatives. The second part of the chapter deals with gene mapping designs, in which specific genetic variants or genomic regions associated with a disorder or trait are identified. A brief outline of the most popular current approaches to the analysis of the genetics of complex human disorders is also provided.


2004 ◽  
Vol 13 (01) ◽  
pp. 137-143
Author(s):  
F. Martin-Sanchez ◽  
V. Maojo

Abstract:Epidemiologists are reformulating their classical approaches to diseases by considering various issues associated to “omics” areas and technologies. Traditional differences between epidemiology and genetics include background, training, terminologies, study designs and others. Public health and epidemiology are increasingly looking forward to using methodologies and informatics tools, facilitated by the Bioinformatics community, for managing genomic information. Future microarray developments will also facilitate the analysis of entire genomes on single arrays, enhancing genetic epidemiology research. The use of biomarkers, biobanks, and integrated genomic/clinical databases poses serious challenges for bioinformaticians in order to extract useful information and knowledge for biomedical research and healthcare. In this regard, there are various ethical, privacy, informed consent and social implications that should be carefully addressed by researchers, practitioners and policy makers.


ISRN Genetics ◽  
2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Leyla Sahebi ◽  
Saeed Dastgiri ◽  
Khalil Ansarin ◽  
Roya Sahebi ◽  
Seyyed Abolghasem Mohammadi

Genetic epidemiology, as a relatively new issue, aims to explore the independent role of genetic-environmental determinants of diseases. Genetic epidemiology studies, depending on the objective, encompass the most preliminary surveys from the attempts to find family history in the occurrence of diseases to the most advanced surveys including specific strategies by clinical trials in the prevention of genetic diseases. Different objectives in genetic epidemiology studies require special methods and study designs. In this review, chief designs including familial aggregation, heritability, segregation, linkage, and association are evaluated; likewise, the purpose of diverse kinds of studies and analyses is briefly discussed. The utilization of study designs and related analyses according to the aims are the main issues and necessary in the accurate implementation of the study. Some methodological issues in relation to studies on tuberculosis are also reported. Attention to these issues might be useful in the implementation of these methods in the studies designed for the prevention and treatment of genetic disorders.


Author(s):  
Alicja Urbaniak ◽  
Anna Skarpańska-Stejnborn

Abstract. The aim of the study was to review recent findings on the use of POM supplements in athletes of various disciplines and physically active participants. Eleven articles published between 2010 and 2018 were included, where the total number of investigated subjects was 176. Male participants constituted the majority of the group (n = 155), as compared to females (n = 21). 45% of research described was conducted on athletes, whereas the remaining studies were based on highly active participants. Randomised, crossover, double-blind study designs constituted the majority of the experimental designs used. POM supplementation varied in terms of form (pills/juice), dosage (50 ml–500 ml) and time of intervention (7 days–2 months) between studies. Among the reviewed articles, POM supplementation had an effect on the improvement of the following: whole body strength; feeling of vitality; acute and delayed muscle fatigue and soreness; increase in vessel diameter; blood flow and serum level of TAC; reduction in the rate of increase for HR, SBP, CK and LDH; support in the recovery of post-training CK, LDH, CRP and ASAT to their baseline levels; reduction of MMP2, MMP9, hsCRP and MDA; and increased activity of antioxidant enzymes (glutathione peroxidase and superoxide dismutase). In the majority of reviewed articles POM supplementation had a positive effect on a variety of parameters studied and the authors recommended it as a supplement for athletes and physically active bodies.


Pflege ◽  
2018 ◽  
Vol 31 (5) ◽  
pp. 237-244 ◽  
Author(s):  
Caroline Gurtner ◽  
Rebecca Spirig ◽  
Diana Staudacher ◽  
Evelyn Huber
Keyword(s):  

Zusammenfassung. Hintergrund: Die patientenbezogene Komplexität der Pflege ist durch die Merkmale „Instabilität“, „Unsicherheit“ und „Variabilität“ definiert. Aufgrund der reduzierten Aufenthaltsdauer und der steigenden Zahl chronisch und mehrfach erkrankter Personen erhöht sich die Komplexität der Pflege. Ziel: In dieser Studie untersuchten wir das Phänomen patientenbezogener Komplexität aus Sicht von Pflegefachpersonen und Pflegeexpertinnen im Akutspital. Methode: Im Rahmen eines kollektiven Case-Study-Designs schätzten Pflegefachpersonen und Pflegeexpertinnen die Komplexität von Pflegesituationen mit einem Fragebogen ein. Danach befragten wir sie in Einzelinterviews zu ihrer Einschätzung. Mittels Within-Case-Analyse verdichteten wir die Daten induktiv zu Fallgeschichten. In der Cross-Case-Analyse verglichen wir die Fallgeschichten hinsichtlich deduktiv abgeleiteter Merkmale. Ergebnisse: Die Ausprägung der Komplexität hing in den vier Cases im Wesentlichen davon ab, ob klinische Probleme kontrollierbar und prognostizierbar waren. Je nach individuellen Ressourcen der Patientinnen und Patienten stieg bzw. sank die Komplexität. Schlussfolgerungen: Komplexe Patientensituationen fordern von Pflegefachpersonen Fachwissen, Erfahrung, kommunikative Kompetenzen sowie die Fähigkeit zur Reflexion. Berufsanfänger und Berufsanfängerinnen werden zur Entwicklung dieser Fähigkeiten idealerweise durch erfahrene Berufskolleginnen oder -kollegen unterstützt und beraten.


2018 ◽  
Vol 37 (12) ◽  
pp. 1081-1091 ◽  
Author(s):  
Sylvie Naar ◽  
Susan M. Czajkowski ◽  
Bonnie Spring

2020 ◽  
Vol 133 (1) ◽  
pp. 71-78 ◽  
Author(s):  
Anthony T. Lee ◽  
John F. Burke ◽  
Pranathi Chunduru ◽  
Annette M. Molinaro ◽  
Robert Knowlton ◽  
...  

OBJECTIVERecent trials for temporal lobe epilepsy (TLE) highlight the challenges of investigating surgical outcomes using randomized controlled trials (RCTs). Although several reviews have examined seizure-freedom outcomes from existing data, there is a need for an overall seizure-freedom rate estimated from level I data as investigators consider other methods besides RCTs to study outcomes related to new surgical interventions.METHODSThe authors performed a systematic review and meta-analysis of the 3 RCTs of TLE in adults and report an overall surgical seizure-freedom rate (Engel class I) composed of level I data. An overall seizure-freedom rate was also collected from level II data (prospective cohort studies) for validation. Eligible studies were identified by filtering a published Cochrane meta-analysis of epilepsy surgery for RCTs and prospective studies, and supplemented by searching indexed terms in MEDLINE (January 1, 2012–April 1, 2018). Retrospective studies were excluded to minimize heterogeneity in patient selection and reporting bias. Data extraction was independently reverified and pooled using a fixed-effects model. The primary outcome was overall seizure freedom following surgery. The historical benchmark was applied in a noninferiority study design to compare its power to a single-study cohort.RESULTSThe overall rate of seizure freedom from level I data was 72.4% (55/76 patients, 3 RCTs), which was nearly identical to the overall seizure-freedom rate of 71.7% (1325/1849 patients, 18 studies) from prospective cohorts (z = 0.134, p = 0.89; z-test). Seizure-freedom rates from level I and II studies were consistent over the years of publication (R2< 0.01, p = 0.73). Surgery resulted in markedly improved seizure-free outcomes compared to medical management (RR 10.82, 95% CI 3.93–29.84, p < 0.01; 2 RCTs). Noninferiority study designs in which the historical benchmark was used had significantly higher power at all difference margins compared to using a single cohort alone (p < 0.001, Bonferroni’s multiple comparison test).CONCLUSIONSThe overall rate of seizure freedom for temporal lobe surgery is approximately 70% for medically refractory epilepsy. The small sample size of the RCT cohort underscores the need to move beyond standard RCTs for epilepsy surgery. This historical seizure-freedom rate may serve as a useful benchmark to guide future study designs for new surgical treatments for refractory TLE.


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