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Chamberlain NR503 Epidemiology Midterm Exam / Chamberlain NR 503 Midterm Exam (New 2020) : Population Health, Epidemiology & Statistical Principles | 100 % VERIFIED ANSWERS, GRADE A

NR 503 Epidemiology Midterm Exam / NR503 Epidemiology Midterm Exam (Latest): Chamberlain Chamberlain NR 503 Epidemiology Midterm Exam / Chamberlain NR503 Midterm Exam : Population Health, Epidemiology & Statistical Principles Question 1 The population of a city on February 15, 2005, was 36,600. The city has a passive surveillance system that collects hospital and private physician reports of influenza cases every month. During the period between January 1 and April 1, 2005, 2,200 new cases of influenza occurred in the city. Of these cases, 775 persons were ill with influenza according to surveillance reports on April 1, 2005. The monthly incidence rate of active cases of influenza for the 3-month period was: 4 per 1,000 population 17 per 1,000 population 20 per 1,000 population 39 per 1,000 population 130 per 1,000 population Question 2 What would be the effect on age-specific incidence rates of uterine cancer if women with hysterectomies were excluded from the denominator of incidence calculations assuming that most women who have had hysterectomies are older than 50 years of age. The rates in all age groups would remain the same. Only rates in women older than 50 years of age would tend to decrease. Rates in women younger than 50 years would increase compared to women older than 50 years of age. Rates would increase in women older than 50 years of age but may decrease in younger women as they get older. It cannot be determined whether the rates would increase or decrease. Question 3 The ability of a single person to remain free of clinical illness following exposure to an infectious agent is known as: Hygiene Vaccination Herd immunity Immunity Latency Question 4 Which of the following reasons can explain why a person who did not consume the infective food item got sick? They were directly exposed to persons who did eat the infective food item Diarrhea is a general symptom consistent with a number of illnesses There may have been an inaccurate recall of which foods were eaten All of the above None of the above Question 5 Which of the food items (or combination of items) is most likely to be the infective item(s)? Pizza only Ice cream only Neither pizza nor ice cream Both pizza and ice cream Cannot be assumed from the data shown Question 6 The table below describes the number of illnesses and deaths caused by plague in four communities. The case-fatality rate associated with plague is lowest in which community? Community A Community B Community C Community D Question 7 The incidence and prevalence rates of a chronic childhood illness for a specific community are given below. Based on the data, which of the following interpretations best describes disease X? The duration of disease is becoming shorter. The duration of disease is becoming longer. The case-fatality rate of this disease is decreasing. Efforts to prevent new cases of this disease are becoming more successful. The risk of the disease has decreased over the past 20 years. Question 8 The following table gives the mean annual age-specific mortality rates from measles during the first 25 years of life in successive 5-year periods. You may assume that the population is in a steady state (i.e., migrations out are equal to migrations in). Based on the information above, one may conclude: Age-specific mortality rates for measles decreased for the period 1910–1914 to 1925–1929 Age-specific mortality rates for measles increased for the period 1910–1914 to 1925–1929 The case-fatality rate decreased for the period 1910–1914 to 1935–1939 Children born in 1910–1914 had the highest rate of death in all periods Children ages 5 to 9 had the highest rate of death in all periods Question 9 In a country with a population of 16 million people, 175,000 deaths occurred during the year ending December 31, 2005. These included 45,000 deaths from tuberculosis (TB) in 135,000 persons who were sick with TB. Assume that the population remained constant throughout the year. Not all 135,000 cases of TB were contracted during 2005. Which of the following statements is true? The case-fatality rate provides a reasonable estimate of incidence The prevalence of TB for 2005 is equal to the denominator of the case-fatality rate The duration of TB is brief All of the above None of the above Question 10 In 2001, a state enacted a law that required the use of safety seats for all children under 7 years of age and mandatory seatbelt use for all persons. The table below lists the number of deaths due to motor vehicle accidents (MVAs) and the total population by age in 2000 (before the law) and in 2005 (4 years after the law was enacted). Based on the information in the table, it was reported that there was an increased risk of death due to MVAs in the state after the law was passed. These conclusions are: Correct, because there were 1.8 times as many MVA deaths in 2005 as in 2000 Correct, because for each age group, the mortality rates were higher in 2005 than they were in 2000 Correct, because both the total and the age-adjusted mortality rates are higher in 2005 than in 2000 Incorrect, because the age-adjusted mortality rate due to MVA is actually lower in 2005 than in 2000 Incorrect, because the overall mortality rate is the same in both years Question 11 Which of the following is an advantage of active surveillance? Requires less project staff Is relatively inexpensive to employ More accurate due to reduced reporting burden for health care providers Relies on different disease definitions to account for all cases Reporting systems can be developed quickly Question 12 A disease has an incidence of 10 per 1,000 persons per year, and 80% of those affected will die within 1 year. Prior to the year 2000, only 50% of cases of the disease were detected by physician diagnosis prior to death. In the year 2000, a lab test was developed that identified 90% of cases an average of 6 months prior to symptom onset; however, the prognosis did not improve after diagnosis. Which statement is true concerning the duration of the disease after the development of the lab test? Mean duration of a case of the disease is shorter in 2000 Mean duration of a case of the disease is the same in 2000 Mean duration of a case of the disease is longer in 2000 No inference about mean duration can be made since the lab test has only been available for 1 year Question 13 What is the overall attack rate in persons who did not eat ice cream? 30% 33% 35% 44% 58% Question 14 The table below describes the number of illnesses and deaths caused by plague in four communities. The proportionate mortality ratio associated with plague is lowest in which community? Community A Community B Community C Community D Question 15 Which of the following is characteristic of a single-exposure, common-vehicle outbreak? Long latency period before many illnesses develop There is an exponential increase in secondary cases following initial exposures Cases include only those who have been exposed to sick persons The epidemic curve has a normal distribution when plotted against the logarithm of time Wide range in incubation times for sick individuals Question 16 The following table gives the mean annual age-specific mortality rates from measles during the first 25 years of life in successive 5-year periods. You may assume that the population is in a steady state (i.e., migrations out are equal to migrations in). The age-specific mortality rates for the cohort born in 1915-1919 are: 2.4  2.8  1.7  1.5  0.4 2.9  3.7  2.8  2.0  0.6 2.9  2.4  1.7  1.3  0.8 2.4  3.3  2.0  0.6  0.1 1.7  2.8  2.2  1.1  0.2 Question 17 A disease has an incidence of 10 per 1,000 persons per year, and 80% of those affected will die within 1 year. Prior to the year 2000, only 50% of cases of the disease were detected by physician diagnosis prior to death. In the year 2000, a lab test was developed that identified 90% of cases an average of 6 months prior to symptom onset; however, the prognosis did not improve after diagnosis. Comparing the epidemiology of the disease prior to 2000 with the epidemiology of the disease after the development of the lab test, which statement is true concerning the disease in 2000? Incidence is higher and prevalence is higher than in 1999 Incidence is higher in 2000 but prevalence remains the same Incidence is the same in 2000 but prevalence is higher than in 1999 Both incidence and prevalence remain the same as in 1999 Incidence is the same in 2000 but prevalence is lower than in 1999 Question 18 A survey was conducted among 1,000 randomly sampled adult males in the United States in 2005. The results from this survey are shown below. The researchers stated that there was a doubling of risk of hypertension in each age group younger than 60 years of age. You conclude that the researchers’ interpretation: Is correct Is incorrect because prevalence rates are estimated Is incorrect because it was based on proportions of the population sample Is incorrect because incidence rates do not describe risk Is incorrect because the calculations do not include adult females Question 19 Which of the following is a condition which may occur during the incubation period? Onset of clinical illness Receipt of infection Signs and symptoms of disease Transmission of infection Isolation of disease carrier through quarantine Question 20 The incidence and prevalence rates of a chronic childhood illness for a specific community are given below. Based on the data, which of the following interpretations best describes disease X? The duration of disease is becoming shorter. The duration of disease is becoming longer. The case-fatality rate of this disease is decreasing. Efforts to prevent new cases of this disease are becoming more successful. The risk of the disease has decreased over the past 20 years. Question 21 A disease has an incidence of 10 per 1,000 persons per year, and 80% of those affected will die within 1 year. Prior to the year 2000, only 50% of cases of the disease were detected by physician diagnosis prior to death. In the year 2000, a lab test was developed that identified 90% of cases an average of 6 months prior to symptom onset; however, the prognosis did not improve after diagnosis. Which statement is true concerning the duration of the disease after the development of the lab test? Mean duration of a case of the disease is shorter in 2000 Mean duration of a case of the disease is the same in 2000 Mean duration of a case of the disease is longer in 2000 No inference about mean duration can be made since the lab test has only been available for 1 year Question 22 Among those who are 25 years of age, those who have been driving less than 5 years had 13,700 motor vehicle accidents in 1 year, while those who had been driving for more than 5 years had 21,680 motor vehicle accidents during the same time period. It was concluded from these data that 25-year-olds with more driving experience have increased accidents compared to those who started driving later. This conclusion is: Correct based on the data Incorrect because rates are not reported Incorrect because prevalence estimates are given when incidence rates should be reported Incorrect because there are no comparison groups identified Both b and d are correct Question 23 In a country with a population of 16 million people, 175,000 deaths occurred during the year ending December 31, 2005. These included 45,000 deaths from tuberculosis (TB) in 135,000 persons who were sick with TB. Assume that the population remained constant throughout the year. Not all 135,000 cases of TB were contracted during 2005. Which of the following statements is true? The case-fatality rate provides a reasonable estimate of incidence The prevalence of TB for 2005 is equal to the denominator of the case-fatality rate The duration of TB is brief All of the above None of the above Question 24 Which of the following is a condition which may occur during the incubation period? Onset of clinical illness Receipt of infection Signs and symptoms of disease Transmission of infection Isolation of disease carrier through quarantine Question 25 Test A has a sensitivity of 95% and a specificity of 90%. Test B has a sensitivity of 80% and a specificity of 98%. In a community of 10,000 people with 5% prevalence of the disease, Test A has always been given before Test B. What is the best reason for changing the order of the tests? The net sensitivity will be increased if Test B is given first The total number of false positives found by both tests is decreased if Test B is given first The net specificity will be decreased if Test B is given first The total number of false negatives found by both tests is decreased if Test B is given first There is no good reason to change the order of the tests Question 26 In 2001, a state enacted a law that required the use of safety seats for all children under 7 years of age and mandatory seatbelt use for all persons. The table below lists the number of deaths due to motor vehicle accidents (MVAs) and the total population by age in 2000 (before the law) and in 2005 (4 years after the law was enacted). Based on the information in the table, it was reported that there was an increased risk of death due to MVAs in the state after the law was passed. These conclusions are: Correct, because there were 1.8 times as many MVA deaths in 2005 as in 2000 Correct, because for each age group, the mortality rates were higher in 2005 than they were in 2000 Correct, because both the total and the age-adjusted mortality rates are higher in 2005 than in 2000 Incorrect, because the age-adjusted mortality rate due to MVA is actually lower in 2005 than in 2000 Incorrect, because the overall mortality rate is the same in both years Question 27 Which of the following are examples of a population prevalence rate? The number of ear infections suffered by 3-year-old children in March, 2006 The number of persons with hypertension per 100,000 population The number of cases of skin cancer diagnosed in a dermatology clinic b and c All of the above Question 28 The table below describes the number of illnesses and deaths caused by plague in four communities. The case-fatality rate associated with plague is lowest in which community? Community A Community B Community C Community D Question 29 A disease has an incidence of 10 per 1,000 persons per year, and 80% of those affected will die within 1 year. Prior to the year 2000, only 50% of cases of the disease were detected by physician diagnosis prior to death. In the year 2000, a lab test was developed that identified 90% of cases an average of 6 months prior to symptom onset; however, the prognosis did not improve after diagnosis. Which statement is true concerning the duration of the disease after the development of the lab test? Mean duration of a case of the disease is shorter in 2000 Mean duration of a case of the disease is the same in 2000 Mean duration of a case of the disease is longer in 2000 No inference about mean duration can be made since the lab test has only been available for 1 year Question 30 For colorectal cancer diagnosed at an early stage, the disease can have 5-year survival rates of greater than 80%. Which answer best describes early stage colorectal cancer? Incidence rates and mortality rates will be similar Mortality rates will be much higher than incidence rates Incidence rates will be much higher than mortality rates Incidence rates will be unrelated to mortality rates None of the above Question 31 A study found that adults older than age 50 had a higher prevalence of pneumonia than those who were younger than age 50. Which of the following is consistent with this finding? Younger adults have a higher incidence of pneumonia Older adults have a higher case-fatality rate from pneumonia Younger adults with pneumonia are more likely to report being ill than older persons Incidence rates do not vary by age, but older adults have pneumonia for a longer duration compared to younger adults None of the above Question 32 What is the overall attack rate in persons who did not eat ice cream? 30% 33% 35% 44% 58% Question 33 Chicken pox is a highly communicable disease. It may be transmitted by direct contact with a person infected with the varicella-zoster virus (VZV). The typical incubation time is between 10 to 20 days. A boy started school 2 weeks after showing symptoms of chicken pox including mild fever, skin rash, and fluid-filled blisters. One month after the boy returned to school, none of his classmates had been infected by VZV. The main reason was: Herd immunity All had been immunized prior to the school year Contact was after infectious period Subclinical infections were not yet detected Disease was endemic in the class Question 34 The population of a city on February 15, 2005, was 36,600. The city has a passive surveillance system that collects hospital and private physician reports of influenza cases every month. During the period between January 1 and April 1, 2005, 2,200 new cases of influenza occurred in the city. Of these cases, 775 persons were ill with influenza according to surveillance reports on April 1, 2005. What can be inferred about influenza cases occurring in the city? Active surveillance would enable better prevention of influenza The incidence rate would decrease if active surveillance were employed The average duration of influenza is approximately 1 month The actual number of influenza cases occurring in the population is less since hospitals and private physicians may be reporting the same patients. The prevalence rate should be higher since it should be calculated based on all cases of influenza occurring from January 1 through March 30, 2005. Question 35 Which of the following statements are true? More than one answer may be correct. Prevalence rates are always larger than incidence rates In a steady state, the prevalence of disease is equal to the attack rate Diagnostic criteria rarely impact estimates of disease prevalence and incidence Prevalence rates are useful for public health planning Incidence rates can be used to estimate prevalence when the mean duration of the disease is known Question 36 A disease has an incidence of 10 per 1,000 persons per year, and 80% of those affected will die within 1 year. Prior to the year 2000, only 50% of cases of the disease were detected by physician diagnosis prior to death. In the year 2000, a lab test was developed that identified 90% of cases an average of 6 months prior to symptom onset; however, the prognosis did not improve after diagnosis. Which statement is true concerning the disease-specific mortality rate after the development of the lab test? The mortality rate for the disease is decreased in 2000 The mortality rate for the disease is the same in 2000 The mortality rate for the disease is increased in 2000 No inference about the mortality rate can be made since the lab test has only been available for 1 year Question 37 Which of the following characteristics indicate that mortality rates provide a reliable estimate of disease incidence? More than one answer may be correct. Case-fatality rate is low The case-fatality rate is high The duration of disease is short The prevalence of disease is greater than 5% The proportionate mortality is high Question 38 Which of the following statements are true? More than one answer may be correct. A mortality rate is an example of an incidence rate Death certificate data are generally valid regardless of the cause of death Type of disease is the most important predictor of mortality Changing diagnostic criteria does not affect estimates of prevalence and incidence The case-fatality rate is calculated based on the entire population at risk Question 39 For a disease such as liver cancer, which is highly fatal and of short duration, which of the following statements is true? Choose the best answer. Mortality rates will be much higher than incidence rates Mortality rates will be much higher than prevalence rates Incidence rates will be much higher than mortality rates Case-fatality rates will be equal to mortality rates Incidence rates will be equal to mortality rates Question 40 The prevalence rate of a disease is two times greater in women than in men, but the incidence rates are the same in men and women. Which of the following statements may explain this situation? The duration of disease is shorter in women Men are at greater risk for developing the disease The case-fatality rate is lower for women The age-adjusted mortality rate will be higher for women The proportionate mortality rate for the disease is higher for men Question 4 1 In a community-based hypertension testing program called HT-Aware, the detection level for high blood pressure is set at 140 mmHg for systolic blood pressure. A separate testing program called HT-Warning in the same community sets the level at 130 mmHg for high systolic blood pressure. Which statements are likely to be true? The sensitivity of HT-Warning is greater than that of HT-Aware The specificity of HT-Warning is greater than that of HT-Aware The number of false positives is greater with HT-Warning than with HT-Aware The number of false negatives is greater with HT-Warning than with HT-Aware The sensitivity and specificity are the same for both tests Question 42 Which of the following improves the reliability of diabetes screening tests? Having the same lab analyze all samples Taking more than one sample for each subject and averaging the results Insuring that the instrument is standardized before each sample is analyzed a and c only All of the above Question 43 A prostate specific antigen (PSA) test is a quick screening test for prostate cancer. A researcher wants to evaluate it using two groups. Group A consists of 1,500 men who had biopsy-proven adenocarcinoma of the prostate while group B consists of 3,000 age- and race-matched men all of whom showed no cancer at biopsy. The results of the PSA screening test in each group is shown in the table. The PSA screening test is used in the same way in two equal-sized populations of men living in different areas of the United States, but the proportion of false positives among those who have a positive PSA test in the first population is lower than that among those who have a positive PSA test in the second population. What is the likely Its correct for this finding? It is impossible to determine what caused the difference The prevalence of disease is higher in the first population The specificity of the test is lower in the first population The specificity of the test is higher in the first population The prevalence of the disease is lower in the first population Question 44 Two neurologists, Drs. J and K, independently examined 70 magnetic resonance images (MRIs) for evidence of brain tumors. As shown in the table below, the neurologists read each MRI as either “positive” or “negative” for brain tumors. Based on the above information, the overall percent agreement between the two doctors including all observations is: 37.1% 62.9% 65.0% 68.4% 84.6% Question 45 This table represents the results of coronary magnetic resonance (CMR) angiography compared to x-ray angiography (the gold standard in diagnosis of coronary artery disease) in a high-risk population of patients scheduled to undergo x-ray angiography for suspected coronary artery disease. In the general population, the prevalence of coronary artery disease is apporximately 6%. Assuming that this sample of patients is representative of the general population, the sensitivity of the CMR test in the general population would be approximately: Less than 75% Between 75% and 85% Between 85% and 90% Between 90% and 95% Greater than 95% Question 46 This table represents the results of coronary magnetic resonance (CMR) angiography compared to x-ray angiography (the gold standard in diagnosis of coronary artery disease) in a high-risk population of patients scheduled to undergo x-ray angiography for suspected coronary artery disease. After reviewing the results of the test comparison, an epidemiologist decides that the specificity of the test is too low. Using the same CMR images, he raises the cutoff value for a positive test to increase the specificity. What is the likely effect on the sensitivity? Sensitivity will increase Sensitivity will decrease There will be no effect because the two characteristics are unrelated The effect cannot be predicted as it will depend on the prevalence rate Sensitivity will be higher if the positive predictive value is increased   Question 47 In comparing the mammography readings of two technicians who evaluated the same set of 600 mammograms for presence of breast cancer from a generally representative sample of women from the population, Agreement regarding negative or normal mammograms is likely to be low The kappa statistic measures agreement due to chance only Overall percent agreement calculated for both readers may conceal significant disagreements regarding positive tests A kappa of 0.9 would be unsatisfactory A kappa of 0.6 represents poor agreement Question 48 In a country with a population of 16 million people, 175,000 deaths occurred during the year ending December 31, 2005. These included 45,000 deaths from tuberculosis (TB) in 135,000 persons who were sick with TB. Assume that the population remained constant throughout the year. Not all 135,000 cases of TB were contracted during 2005. Which of the following statements is true? The case-fatality rate provides a reasonable estimate of incidence The prevalence of TB for 2005 is equal to the denominator of the case-fatality rate The duration of TB is brief All of the above None of the above Question 49 Which of the following statements pertains to relative survival? Refers to survival of first-degree relatives Is equal to the case-fatality rate Is generally closer to observed survival rates in younger age groups Is generally closer to observed survival rates in older age groups Provides an estimate of proportionate mortality Question 50 An important assumption in this type of analysis is that: No change has occurred in the effectiveness of treatment during the 3-year period Treatment has improved during the period of the study Persons lost to follow-up are counted in the table The data are age-adjusted Both a and c