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Experimental studies provide the strongest evidence for the etiology of disease, but they must also be designed carefully to eliminate subtle effects of
bias . Typically, experimental studies with humans are conducted as
double-blind studies , meaning neither the subjects nor the researchers know who is a treatment case and who is not. This design removes a well-known cause of bias in research called the
placebo effect , in which knowledge of the treatment by either the subject or the researcher can influence the outcomes.
- Describe the advantages and disadvantages of observational studies and experimental studies.
- Explain the ways that groups of subjects can be selected for analytical studies.
Part 3
Since laboratory tests had confirmed
Salmonella , a common foodborne pathogen, as the etiologic agent, epidemiologists suspected that the outbreak was caused by contamination at a food processing facility serving the region. Interviews with patients focused on food consumption during and after the Thanksgiving holiday, corresponding with the timing of the outbreak. During the interviews, patients were asked to list items consumed at holiday gatherings and describe how widely each item was consumed among family members and relatives. They were also asked about the sources of food items (e.g., brand, location of purchase, date of purchase). By asking such questions, health officials hoped to identify patterns that would lead back to the source of the outbreak.
Analysis of the interview responses eventually linked almost all of the cases to consumption of a holiday dish known as the
turducken —a chicken stuffed inside a duck stuffed inside a turkey. Turducken is a dish not generally consumed year-round, which would explain the spike in cases just after the Thanksgiving holiday. Additional analysis revealed that the turduckens consumed by the affected patients were purchased already stuffed and ready to be cooked. Moreover, the pre-stuffed turduckens were all sold at the same regional grocery chain under two different brand names. Upon further investigation, officials traced both brands to a single processing plant that supplied stores throughout the Florida panhandle.
- Is this an example of common source spread or propagated spread?
- What next steps would the public health office likely take after identifying the source of the outbreak?
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Key concepts and summary
- Early pioneers of epidemiology such as John Snow, Florence Nightingale, and Joseph Lister, studied disease at the population level and used data to disrupt disease transmission.
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Descriptive epidemiology studies rely on case analysis and patient histories to gain information about outbreaks, frequently while they are still occurring.
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Retrospective epidemiology studies use historical data to identify associations with the disease state of present cases.
Prospective epidemiology studies gather data and follow cases to find associations with future disease states.
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Analytical epidemiology studies are observational studies that are carefully designed to compare groups and uncover associations between environmental or genetic factors and disease.
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Experimental epidemiology studies generate strong evidence of causation in disease or treatment by manipulating subjects and comparing them with control subjects.
Matching
Match each type of epidemiology study with its description.
___experimental |
A. examination of past case histories and medical test results conducted on patients in an outbreak |
___analytical |
B. examination of current case histories, interviews with patients and their contacts, interpretation of medical test results; frequently conducted while outbreak is still in progress |
___prospective |
C. use of a set of test subjects (human or animal) and control subjects that are treated the same as the test subjects except for the specific treatment being studied |
___descriptive |
D. observing groups of individuals to look for associations with disease |
___retrospective |
E. a comparison of a cohort of individuals through the course of the study |
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Match each pioneer of epidemiology with his or her contribution.
___Florence Nightingale |
A. determined the source of a cholera outbreak in London |
___Robert Koch |
B. showed that surgical wound infection rates could be dramatically reduced by using carbolic acid to disinfect surgical tools, bandages, and surgical sites |
___Joseph Lister |
C. compiled data on causes of mortality in soldiers, leading to innovations in military medical care |
___John Snow |
D. developed a methodology for conclusively determining the etiology of disease |
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Fill in the blank
________occurs when an infected individual passes the infection on to other individuals, who pass it on to still others, increasing the penetration of the infection into the susceptible population.
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A batch of food contaminated with botulism exotoxin, consumed at a family reunion by most of the members of a family, would be an example of a ________ outbreak.
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Short answer
Questions & Answers
I'm interested in biological psychology and cognitive psychology
what does preconceived mean
How can I develope my cognitive domain
why is communication effective
Communication is effective because it allows individuals to share ideas, thoughts, and information with others.
effective communication can lead to improved outcomes in various settings, including personal relationships, business environments, and educational settings. By communicating effectively, individuals can negotiate effectively, solve problems collaboratively, and work towards common goals.
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miss
Every time someone flushes a toilet in the apartment building, the person begins to jumb back automatically after hearing the flush, before the water temperature changes. Identify the types of learning, if it is classical conditioning identify the NS, UCS, CS and CR. If it is operant conditioning, identify the type of consequence positive reinforcement, negative reinforcement or punishment
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Wekolamo
because it helps many people around the world to understand how to interact with other people and understand them well, for example at work (job).
Agreed 👍 There are many parts of our brains and behaviors, we really need to get to know. Blessings for everyone and happy Sunday!
ARC
A child is a member of community not society elucidate ?
Isn't practices worldwide, be it psychology, be it science. isn't much just a false belief of control over something the mind cannot truly comprehend?
compare and contrast skinner's perspective on personality development on freud
Skinner skipped the whole unconscious phenomenon and rather emphasized on classical conditioning
war
explain how nature and nurture affect the development and later the productivity of an individual.
nature is an hereditary factor while nurture is an environmental factor which constitute an individual personality. so if an individual's parent has a deviant behavior and was also brought up in an deviant environment, observation of the behavior and the inborn trait we make the individual deviant.
Samuel
I am taking this course because I am hoping that I could somehow learn more about my chosen field of interest and due to the fact that being a PsyD really ignites my passion as an individual the more I hope to learn about developing and literally explore the complexity of my critical thinking skills
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Jonathan
generally amnesi how long yrs memory loss
interpersonal relationships
What would be the best educational aid(s) for gifted kids/savants?
treat them normal, if they want help then give them.
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Saurabh
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Source:
OpenStax, Microbiology. OpenStax CNX. Nov 01, 2016 Download for free at http://cnx.org/content/col12087/1.4
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