In the early 1980âs, epidemiologists recognized that AIDS occurred most frequently among men who had sex with men and in intravenous drug users. How this information might be used for each of the following:
1) Population or community health assessment
2) Search for causes
3) Individual decisions
In the early 1980âs, epidemiologists recognized that AIDS occurred most frequently among men who had sex with men and in intravenous drug users. How this information might be used for each of the following:
1) Population or community health assessment
2) Search for causes
3) Individual decisions
Related textbook solutions
Related questions
This includes showing all calculations and explaining why you selected a specific answer for each multiple choice question (i.e. donât just circle the correct answer). I am looking to see how you got the answer, not just that you have the correct answer.
Below is data from the United States Cancer Statistics about the number of news cases of lung cancer in males in the U.S. for 2011 for ages 30 and older.
Table 1: U.S. Population Size and Incidence Cases of Lung Cancer in Males for 2011
| Age (Years) | U.S. Male Population | White Population | White Incidence Cases | Black Population | Black Incidence Cases |
| 30-34 | 10,181,564 | 7,950,924 | 88 | 1,383,650 | 22 |
| 35-39 | 9,666,162 | 7,557,263 | 212 | 1,271,897 | 23 |
| 40-44 | 10,363,126 | 8,259,215 | 643 | 1,324,847 | 132 |
| 45-49 | 10,856,131 | 8,766,225 | 2,032 | 1,373,346 | 444 |
| 50-54 | 10,976,172 | 9,004,383 | 5,128 | 1,329,551 | 1,148 |
| 55-59 | 9,733,849 | 8,101,629 | 8,607 | 1,091,030 | 1,687 |
| 60-64 | 8,466,308 | 7,183,960 | 12,340 | 845,362 | 2,067 |
| 65-69 | 6,014,777 | 5,178,255 | 15,792 | 539,796 | 2,077 |
| 70-74 | 4,360,942 | 3,769,569 | 16,011 | 376,129 | 1,864 |
| 75-79 | 3,204,196 | 2,807,216 | 14,319 | 255,221 | 1,426 |
| 80-84 | 2,319,839 | 2,078,071 | 11,284 | 154,155 | 883 |
| 85+ | 1,873,942 | 1,688,433 | 7,616 | 117,267 | 545 |
| Total | 88,017,008 | 72,345,143 | 94,072 | 10,062,251 | 12,318 |
3. What is the age-specific incidence rate for lung cancer in white men age 75-79 for 2011?(1 pt)
0.005 per 1000
1.3 per 1000
1.2 per 1000
5.1 per 1000
5.6 per 1000
F. Cannot be calculated from the given information
4. What is the age-specific incidence rate for lung cancer in black men age 75-79 for 2011? (1 pt)
0.005 per 1000
1.3 per 1000
1.2 per 1000
5.1 per 1000
5.6 per 1000
F. Cannot be calculated from the given information
Questions 5 through 7 are based on the information below:
Using the information in Table 1, researchers calculated the crude incidence rates and age-adjusted incidence rates (via the direct method) for both groups.
Table 2: Crude incidence rates and age-adjusted incidence rates for white and black males
| White Males | Black Males | ||
| Crude Incidence Rate | Age-adjusted Incidence Rate | Crude Incidence Rate | Age-adjusted Incidence Rate |
| 1.3 per 1000 | 1.2 per 1000 | 1.2 per 1000 | 1.5 per 1000 |
5. True or False, there is likely a difference in the age composition between the white and black males. Explain your answer
6. Based on the information in Table 2, it was reported that there was an increased risk of lung cancer in black males in 2011. (1 pt)
The conclusion is:
Correct, the age-adjusted rate is higher in black males compared to white males
Correct, because both the crude and age-adjusted rates are higher in black males compared to white males
Incorrect, because the incidence rate for white males is actually higher than the incidence rate for black males
7. What type of age-adjusted rate was calculated in table 2? How does it differ from the age-adjusted rate in question 5 in the in-class exercise for age-adjustments? Hint: See slide title: Adjustments for Other Measures of Disease Frequency in the lecture title Adjusted Rates (1 pt)
Question 8 is based on the information given below:
Cause-specific mortality rates for men in 2010 in the U.S. from various types of cancers are shown in the table below:
Cause-Specific Mortality Rates
(per 100,000 Men)
Location of the Cancer
in the Body White Asian
Pancreas 13.2 5.7
Prostate 19.1 2.5
Lung 62.3 18.5
Skin 4.9 0.3
8. The inference that White men in the U.S. are at higher risk of death due to cancer of the pancreas, prostate, lung, and skin compared to Asian men in the U.S. is
A. correct
B. incorrect because of failure to determine cause-specific mortality rates
incorrect because proportionate mortality alone does not give an estimate of risk
D. incorrect because of failure to adjust for differences in the age composition of the two populations
E. incorrect because counts were used when cause-specific mortality rates were needed
9. In January 1996, a team of epidemiologists identified a sample of 4,500 men, 65-74 years of age, for a study of prostate cancer. Tests indicated that 315 of the men already had prostate cancer and, therefore, were not at risk. The rest of the men were followed prospectively for five years to determine the incidence rate of prostate cancer in the sample. By the end of the five years of follow-up 156 of the men had developed prostate cancer. What is the incidence rate of prostate cancer in this group?
10. An epidemiologic investigation that started on January 1, 2011, identified a population of 1,000 individuals. At the start of the study 4 were found to have the disease. During the year of study, 6 new cases were found; thus a total of 10 cases were identified. Among those 10 cases, 6 deaths occurred during the year. What was the prevalence of the disease during the 1-year study?
| CASE STUDY |
| It used to be that epidemiologists at the CDC only knew that you had the flu when you visited your doctor and the doc- tor then reported that information to other agencies. By the time this information made its way to the CDC or state health departments, it was often several days old, which meant that the medical community was always playing catch-up. And of course, your doctor was only aware of your illness if you showed up at his office, not when you decided to tough it out at home. Nowadays, however, before you ever go to the doc- tor, you are likely to search the Internet for âflu symptoms,â tweet your suddenly declining health status, or Instagram yourself lying in bed. Study the case below, which shows how the Internet and social media have impacted the field of epi- demiology, and then answer the questions that follow. Google Used to Predict Influenza Outbreaksâ2008 In 2008, Google launched Google Flu Trends, an applica- tion that compiles aggregated data from key word searches for clinical terms, such as thermometer, chest congestion, muscle aches, or flu symptoms. Google reports the data on a website, which then provides an early-warning system for the locations of new flu outbreaks. Because the data are collected from searches performed each day, trends in flu symptoms become apparent much more quickly than when they are based on data reported during office vis- its or in lab reports from physicians around the country. When the CDC compared actual cases over the course of a year with Googleâs findings, the data from the two sources matched. Initially, Google was only compiling information about flu trends in the United States and Canada. But after the H1N1 virus appeared in Mexico in 2009, the CDC asked Google to go back and look at Internet searches conducted by people in Mexico during that time. Evaluation of the data indicated that Google detected an uptick several days before the CDC did (Figure 23.1). 1,200 1,000 800 600 400 200 0 Influenza activity 1113151719212325272931 2 4 6 8 1012141618202224262830 2 Suspected Confirmed Mar Apr May Date of illness onset Intense High Moderate Low Minimal Jul Aug Sep Oct Nov Dec Jan Feb Mar Apr May Jun Figure 23.1 2009 Inflenza activity (a) Data from the Centers for Disease Control, based on physical examination by health care providers, shows a peak in influenza cases in late April. (b) Google âFlu Trendsâ shows an influenza peak in February. |
No. of cases
Case Study Exercise 23 Morbidity and Mortality Weekly Report 199
Epidemic tracking based on Internet searches reflects what is called collective intelligence. It works because indi- viduals using their personal computers tend to search for terms related to their immediate needs and intentions, and they generally do this before presenting in a doctorâs office or emergency room. The methodology used in the Google search was published in the prestigious science journal Nature, and another independent study has been published about a similar search analysis conducted by Yahoo, showing that it was effective in predicting flu trends.
Some people worry that data collected from Internet searches may compromise individualsâ privacy. However,
Google maintains that Flu Trends cannot be used to iden- tify individual users because the data are anonymous and are aggregated before being presented. Another potential drawback is that this data collection method is less likely to be useful for tracking epidemics in societies having a low percentage of computer ownership, namely, developing countries. However, considering the high stakes involved in identifying an epidemic quickly, Internet search term analy- sis holds great promise for public health. And, unlike most health innovations, itâs free!
3. How might data collected in this way not be representative of a particular population?
4. Explain why the two graphs in Figure 23.1 do not show influenza activity peaking at the same time.
6. In 2013, Google Flu Trends vastly overestimated the number of cases of the flu in the United States. One explanation for this was that there was a greater than usual number of media reports about influenza early in the flu season. Based on your knowledge of how Flu Trends works, explain why Google missed the mark in 2013
It is the early 1990s. The World Health Organization is planning a program for the global eradication of polio by the year 2000. Likura, a fictitious nation south-central Africa, may become one of the countries selected to test the effectiveness of WHOs polio eradication strategies. Unfortunately, little is known about polio in Likura. The Minister of Health therefore assigned the task of assessing the polio situation to a Ministry worker who has recently returned from an epidemiology course in Atlanta, and who is about to become the District Health Officer in the Ababo District. The Ababo District is a relatively poor rural district with a single hospital and several health centers. The Ababo District has attempted to conduct surveillance on polio cases and deaths over the past five years. The hospital, health centers, and all health workers are supposed to report such cases to the District Health Officer. One measure of the polio situation in a community is the prevalence of lameness in children, since lameness is a common sequel of polio. Question 1a: What data might you use (or collect) to determine the incidence of polio in the population?
Question 1b: What data might you use (or collect) to determine the prevalence of polio in the population?
Question 2: What is the difference between active and passive surveillance systems? Is the Ababo surveillance system for polio passive or active? To gather information on polio prevalence, vaccine coverage, and risk factors for polio, the District Health Officer conducted a survey of children in the district. Lameness was used as a surrogate for polio. The prevalence of lameness by vaccination status is shown in
able Lameness by Vaccination Status among Children 12-23 Months of Age, Ababo District, 1991.
| Lame | Normal | |||
| Polio Vaccine | 1 dose | 1 | 242 | 243 |
| 0 doses | 9 | 667 | 676 | |
| 10 | 909 | 919 |
Question 3: What is the prevalence of polio (lameness) among vaccinated (1 dose) children?
Question 4: What is the prevalence of polio (lameness) among the unvaccinated children?
Question 5: What is the vaccine coverage (at least one dose) in this population? Question 6: Interpret these data.
