BIO 550 Describe the key features of descriptive and analytic epidemiology
BIO 550 Describe the key features of descriptive and analytic epidemiology
DQ1 Describe the key features of descriptive and analytic epidemiology. How are the two used in conjunction with one another?
DQ2 What is a clinical trial? Support your description with literary rationale. Why do you believe clinical trials are beneficial?
The experimental method is the most powerful tool in defining the etiology of recurring developmental anomalies. The basic approach of the applied experimental method is to take one or two of the most likely hypotheses and test them one at a time on part of the herd, using other untreated animals as controls. It is important to randomly select individuals to remove sample bias. If the herd is large, it may be divided into a number of groups, allowing for the simultaneous testing of more than one hypothesis, but this depends on the prevalence of the anomalies. For example, the herd could be divided into four groups: old animals with access to suspected toxicant; young animals with access to suspected toxicant; old animals with no access; and young animals with no access. Developmental anomalies of low prevalence require larger sized groups. Usually, a prevalence of 25% will allow a group size of 50 animals, depending on the variability of expression of the defect.
Records at the termination of the experiment (the next calving season) should include reproductive problems, abortions, stillbirths, and anomalies. Statistical tests to determine if the differences between test and control groups are statistically significant can be used. A statistical difference in the prevalence of anomalies between the two groups is evidence that the risk factor tested is the cause of the anomalies. It should be remembered that lack of statistical significance does not necessarily “disprove” associations among groups, as this often occurs in low prevalence situations with inadequately-sized test and control groups. With proper randomization and care in treating the two groups similarly, a statistical difference in the prevalence of anomalies between two groups is evidence that the risk factor tested is the cause of the anomalies.
In summary, identification of the etiology of developmental anomalies is often extremely difficult, for many reasons. First, defective development alone often does not give clues to a specific cause. Second, specific teratogens such as viruses, plants and toxins, often cannot be demonstrated at the time of expulsion of the defective fetus, or even after intensive pathological and toxicologic investigations. Third, except for certain chromosomal aberrations, hereditary factors are recognized only when they occur in characteristic intra-generational familial frequencies and patterns. Therefore, when a cause cannot be demonstrated, attempts to determine patterns of occurrence must be undertaken. The method described provides a step-wise protocol to determine etiology.
| Excellent | Good | Fair | Poor | ||
| Main Posting | 45 (45%) – 50 (50%)
Answers all parts of the discussion question(s) expectations with reflective critical analysis and synthesis of knowledge gained from the course readings for the module and current credible sources. Supported by at least three current, credible sources. Written clearly and concisely with no grammatical or spelling errors and fully adheres to current APA manual writing rules and style. |
40 (40%) – 44 (44%)
Responds to the discussion question(s) and is reflective with critical analysis and synthesis of knowledge gained from the course readings for the module. At least 75% of post has exceptional depth and breadth. Supported by at least three credible sources. Written clearly and concisely with one or no grammatical or spelling errors and fully adheres to current APA manual writing rules and style. |
35 (35%) – 39 (39%)
Responds to some of the discussion question(s). One or two criteria are not addressed or are superficially addressed. Is somewhat lacking reflection and critical analysis and synthesis. Somewhat represents knowledge gained from the course readings for the module. Post is cited with two credible sources. Written somewhat concisely; may contain more than two spelling or grammatical errors. Contains some APA formatting errors. |
0 (0%) – 34 (34%)
Does not respond to the discussion question(s) adequately. Lacks depth or superficially addresses criteria. Lacks reflection and critical analysis and synthesis. Does not represent knowledge gained from the course readings for the module. Contains only one or no credible sources. Not written clearly or concisely. Contains more than two spelling or grammatical errors. Does not adhere to current APA manual writing rules and style. |
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| Main Post: Timeliness | 10 (10%) – 10 (10%)
Posts main post by day 3. |
0 (0%) – 0 (0%) | 0 (0%) – 0 (0%) | 0 (0%) – 0 (0%)
Does not post by day 3. |
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| First Response | 17 (17%) – 18 (18%)
Response exhibits synthesis, critical thinking, and application to practice settings. Responds fully to questions posed by faculty. Provides clear, concise opinions and ideas that are supported by at least two scholarly sources. Demonstrates synthesis and understanding of learning objectives. Communication is professional and respectful to colleagues. Responses to faculty questions are fully answered, if posed. Response is effectively written in standard, edited English. |
15 (15%) – 16 (16%)
Response exhibits critical thinking and application to practice settings. Communication is professional and respectful to colleagues. Responses to faculty questions are answered, if posed. Provides clear, concise opinions and ideas that are supported by two or more credible sources. Response is effectively written in standard, edited English. |
13 (13%) – 14 (14%)
Response is on topic and may have some depth. Responses posted in the discussion may lack effective professional communication. Responses to faculty questions are somewhat answered, if posed. Response may lack clear, concise opinions and ideas, and a few or no credible sources are cited. |
0 (0%) – 12 (12%)
Response may not be on topic and lacks depth. Responses posted in the discussion lack effective professional communication. Responses to faculty questions are missing. No credible sources are cited. |
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| Second Response | 16 (16%) – 17 (17%)
Response exhibits synthesis, critical thinking, and application to practice settings. Responds fully to questions posed by faculty. Provides clear, concise opinions and ideas that are supported by at least two scholarly sources. Demonstrates synthesis and understanding of learning objectives. Communication is professional and respectful to colleagues. Responses to faculty questions are fully answered, if posed. Response is effectively written in standard, edited English. |
14 (14%) – 15 (15%)
Response exhibits critical thinking and application to practice settings. Communication is professional and respectful to colleagues. Responses to faculty questions are answered, if posed. Provides clear, concise opinions and ideas that are supported by two or more credible sources. Response is effectively written in standard, edited English. |
12 (12%) – 13 (13%)
Response is on topic and may have some depth. Responses posted in the discussion may lack effective professional communication. Responses to faculty questions are somewhat answered, if posed. Response may lack clear, concise opinions and ideas, and a few or no credible sources are cited. |
0 (0%) – 11 (11%)
Response may not be on topic and lacks depth. Responses posted in the discussion lack effective professional communication. Responses to faculty questions are missing. No credible sources are cited. |
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| Participation | 5 (5%) – 5 (5%)
Meets requirements for participation by posting on three different days. |
0 (0%) – 0 (0%) | 0 (0%) – 0 (0%) | 0 (0%) – 0 (0%)
Does not meet requirements for participation by posting on 3 different days. |
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| Total Points: 100 | |||||