NR 503 WEEK 8 FINAL EXAM QUESTIONS AND ANSWERS 100% CORRECTLY/VERIFIED BEST GRADED A+ GUA, Exams of Nursing

Download NR 503 WEEK 8 FINAL EXAM QUESTIONS AND ANSWERS 100% CORRECTLY/VERIFIED BEST GRADED A+ GUA and more Exams Nursing in PDF only on Docsity! Immunity The epidemic curve has a normal distribution when plotted against the logarithm of time NR 503 WEEK 8 FINAL EXAM QUESTIONS AND ANSWERS 100% CORRECTLY/VERIFIED BEST GRADED A+ GUARANTEED SUCCESS LATEST UPDATE 2022 Chapters 2-4 The ability of a single person to remain free of clinical illness following exposure to an infectious agent is known as: Which of the following is characteristic of a single-exposure, common-vehicle outbreak? What is the diarrhea attack rate in persons who ate both ice cream & pizza? NR 503 WEEK 8 FINAL EXAM QUESTIONS AND ANSWERS 100% CORRECTLY/VERIFIED BEST GRADED A+ GUARANTEED SUCCESS LATEST UPDATE 2022 Transmission of infection 39/52 33% NR 503 WEEK 8 FINAL EXAM QUESTIONS AND ANSWERS 100% CORRECTLY/VERIFIED BEST GRADED A+ GUARANTEED SUCCESS LATEST UPDATE 2022 What is the overall attack rate in persons who did not eat ice cream? Which of the following is a condition which may occur during the incubation period? 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, & fluid-filled blisters. One month after the boy returned to school, none of his classmates had been infected by VZV. The main reason was: Contact was after infectious period NR 503 WEEK 8 FINAL EXAM QUESTIONS AND ANSWERS 100% CORRECTLY/VERIFIED BEST GRADED A+ GUARANTEED SUCCESS LATEST UPDATE 2022 NR 503 WEEK 8 FINAL EXAM QUESTIONS AND ANSWERS 100% CORRECTLY/VERIFIED BEST GRADED A+ GUARANTEED SUCCESS LATEST UPDATE 2022 students who are girls (343 + 77). The attack rate is 3.3%. An outbreak of gastroenteritis occurred at a boarding school with a student enrollment of 846. Fifty- seven students reported symptoms including vomiting, diarrhea, nausea, & low-grade fever between 10 p.m. on September 24 & 8 p.m. on September 25. The ill students lived in dormitories that housed NR 503 WEEK 8 FINAL EXAM QUESTIONS AND ANSWERS 100% CORRECTLY/VERIFIED BEST GRADED A+ GUARANTEED SUCCESS LATEST UPDATE 2022 NR 503 WEEK 8 FINAL EXAM QUESTIONS AND ANSWERS 100% CORRECTLY/VERIFIED BEST GRADED A+ GUARANTEED SUCCESS LATEST UPDATE 2022 723 of the students. The table below provides information on the number of students per type of residence & the number reporting illnesses consistent with the described symptoms & onset time. What is the proportion of total cases occurring in boys? The proportion of cases occurring in boys is equal to the number of cases in boys divided by the total number of cases (43/57). This equals 75.4%. An outbreak of gastroenteritis occurred at a boarding school with a student enrollment of 846. Fifty- seven students reported symptoms including vomiting, diarrhea, nausea, & low-grade fever between 10 p.m. on September 24 & 8 p.m. on September 25. The ill students lived in dormitories that housed 723 of the students. The table below provides information on the number of students per type of residence & the number reporting illnesses consistent with the described symptoms & onset time. What is the proportion of total cases occurring in students who live in dormitories? The proportion of cases occurring in dormitory residents is equal to the number of cases in residents divided by the total number of cases (52/57). This equals 91.2%. An outbreak of gastroenteritis occurred at a boarding school with a student enrollment of 846. Fifty- seven students reported symptoms including vomiting, diarrhea, nausea, & low-grade fever between 10 p.m. on September 24 & 8 p.m. NR 503 WEEK 8 FINAL EXAM QUESTIONS AND ANSWERS 100% CORRECTLY/VERIFIED BEST GRADED A+ GUARANTEED SUCCESS LATEST UPDATE 2022 NR 503 WEEK 8 FINAL EXAM QUESTIONS AND ANSWERS 100% CORRECTLY/VERIFIED BEST GRADED A+ GUARANTEED SUCCESS LATEST UPDATE 2022 on September 25. The ill students lived in dormitories that housed 723 of the students. The table below provides information on the number of students per type of residence & the number reporting illnesses consistent with the described symptoms & onset time. Which proportion is more informative for the purpose of the outbreak investigation? Both proportions are useful. Dormitory residents account for over 90% of the cases indicating an outbreak of an infectious agent that was transmitted at the school. Furthermore, over 75% of the cases were boys indicating that the responsible agent was more likely to have been transmitted in the boys’ dormitory. A group of researchers are interested in conducting a clinical trial to determine whether a new cholesterol-lowering agent was useful in preventing coronary heart disease (CHD). They identified 12,327 potential participants for the trial. At the initial clinical exam, 309 were discovered to have CHD. The remaining subjects entered the trial & were divided equally into the treatment & placebo groups. Of those in the treatment group, 505 developed CHD after 5 years of follow-up while 477 developed CHD during the same period in the placebo group. What was the prevalence of CHD at the initial exam? The prevalence of CHD at the initial exam was 309 cases of CHD divided by 12,327 participants. This equals a prevalence of 25.1 cases of CHD per 1,000 persons. NR 503 WEEK 8 FINAL EXAM QUESTIONS AND ANSWERS 100% CORRECTLY/VERIFIED BEST GRADED A+ GUARANTEED SUCCESS LATEST UPDATE 2022 Is incorrect because prevalence rates are estimated NR 503 WEEK 8 FINAL EXAM QUESTIONS AND ANSWERS 100% CORRECTLY/VERIFIED BEST GRADED A+ GUARANTEED SUCCESS LATEST UPDATE 2022 A survey was conducted among 1,000 r&omly 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: NR 503 WEEK 8 FINAL EXAM QUESTIONS AND ANSWERS 100% CORRECTLY/VERIFIED BEST GRADED A+ GUARANTEED SUCCESS LATEST UPDATE 2022 NR 503 WEEK 8 FINAL EXAM QUESTIONS AND ANSWERS 100% CORRECTLY/VERIFIED BEST GRADED A+ GUARANTEED SUCCESS LATEST UPDATE 2022 NR 503 WEEK 8 FINAL EXAM QUESTIONS AND ANSWERS 100% CORRECTLY/VERIFIED BEST GRADED A+ GUARANTEED SUCCESS LATEST UPDATE 2022 The duration of disease is becoming shorter. NR 503 WEEK 8 FINAL EXAM QUESTIONS AND ANSWERS 100% CORRECTLY/VERIFIED BEST GRADED A+ GUARANTEED SUCCESS LATEST UPDATE 2022 The incidence & 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? A prevalence survey conducted from January 1 through December 31, 2003 identified 580 new cases of tuberculosis in a city of 2 million persons. The incidence rate of tuberculosis in this population has historically been 1 per 4,000 persons each year. What is the incident rate of tuberculosis per 100,000 persons in 2003? The answer is 29 new cases of tuberculosis per 100,000 persons. This is found by dividing the new cases of tuberculosis by the total population at risk (580/2,000,000) & multiplying this rate by 100,000 to st&ardize the rate. A prevalence survey conducted from January 1 through December 31, 2003 identified 580 new cases of tuberculosis in a city of 2 million persons. The incidence rate of tuberculosis in this population has historically been 1 per 4,000 persons each year. Has the risk of tuberculosis increased or decreased NR 503 WEEK 8 FINAL EXAM QUESTIONS AND ANSWERS 100% CORRECTLY/VERIFIED BEST GRADED A+ GUARANTEED SUCCESS LATEST UPDATE 2022 The average duration of influenza is approximately 1 month Incidence rates do not vary by age, but older adults have pneumonia for a longer duration compared to younger adults NR 503 WEEK 8 FINAL EXAM QUESTIONS AND ANSWERS 100% CORRECTLY/VERIFIED BEST GRADED A+ GUARANTEED SUCCESS LATEST UPDATE 2022 775 persons were ill with influenza according to surveillance reports on April 1, 2005. The prevalence rate of active influenza as of April 1, 2005, was: 20 per 1,000 population The population of a city on February 15, 2005, was 36,600. The city has a passive surveillance system that collects hospital & private physician reports of influenza cases every month. During the period between January 1 & 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? 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? NR 503 WEEK 8 FINAL EXAM QUESTIONS AND ANSWERS 100% CORRECTLY/VERIFIED BEST GRADED A+ GUARANTEED SUCCESS LATEST UPDATE 2022 Incidence rates can be used to estimate prevalence when the mean duration of the disease is known Prevalence rates are useful for public health planning Incidence is higher & prevalence is higher than in 1999 NR 503 WEEK 8 FINAL EXAM QUESTIONS AND ANSWERS 100% CORRECTLY/VERIFIED BEST GRADED A+ GUARANTEED SUCCESS LATEST UPDATE 2022 Which of the following statements are true? More than one answer may be correct. A disease has an incidence of 10 per 1,000 persons per year, & 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? NR 503 WEEK 8 FINAL EXAM QUESTIONS AND ANSWERS 100% CORRECTLY/VERIFIED BEST GRADED A+ GUARANTEED SUCCESS LATEST UPDATE 2022 NR 503 WEEK 8 FINAL EXAM QUESTIONS AND ANSWERS 100% CORRECTLY/VERIFIED BEST GRADED A+ GUARANTEED SUCCESS LATEST UPDATE 2022 A disease has an incidence of 10 per 1,000 persons per year, & 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 NR 503 WEEK 8 FINAL EXAM QUESTIONS AND ANSWERS 100% CORRECTLY/VERIFIED BEST GRADED A+ GUARANTEED SUCCESS LATEST UPDATE 2022 NR 503 WEEK 8 FINAL EXAM QUESTIONS AND ANSWERS 100% CORRECTLY/VERIFIED BEST GRADED A+ GUARANTEED SUCCESS LATEST UPDATE 2022 below lists the number of deaths due to motor vehicle accidents (MVAs) & the total population by age in 2000 (before the law) & in 2005 (4 years after the law was enacted). What is the age-specific mortality rate due to MVAs for children ages 0 to 18 years in 2000? NR 503 WEEK 8 FINAL EXAM QUESTIONS AND ANSWERS 100% CORRECTLY/VERIFIED BEST GRADED A+ GUARANTEED SUCCESS LATEST UPDATE 2022 6.1 per 1,000 NR 503 WEEK 8 FINAL EXAM QUESTIONS AND ANSWERS 100% CORRECTLY/VERIFIED BEST GRADED A+ GUARANTEED SUCCESS LATEST UPDATE 2022 In 2001, a state enacted a law that required the use of safety seats for all children under 7 years of age & m&atory seatbelt use for all persons. The table below lists the number of deaths due to motor vehicle accidents (MVAs) & the total population by age in 2000 (before the law) & in 2005 (4 years after the law was enacted). Using the pooled total of the 2000 & 2005 populations as the st&ard rate, calculate the age-adjusted mortality rate due to MVAs in 2005. The correct answer is 2.3 MVA deaths per 1,000 persons. The key to calculating the age-adjusted rate is to pool the observed numbers for both time periods & to calculate the expected numbers of deaths in the 2005 population assuming that a common rate applied to the population. For example, for those under 7 years, the pooled rate equals (44 + 20) divided by (3,500 + 4,000). The pooled rate for this group is 8.5 per 1,000 persons. When this rate is multiplied by the 4,000 children under 7 years of age in 2005, the expected number of deaths is 34.13. Performing the same calculation for each age group results in 111.7 deaths in those 7 to 18 years of age, 175.8 deaths in those 19 to NR 503 WEEK 8 FINAL EXAM QUESTIONS AND ANSWERS 100% CORRECTLY/VERIFIED BEST GRADED A+ GUARANTEED SUCCESS LATEST UPDATE 2022 Correct, because both the total & the age-adjusted mortality rates are higher in 2005 than in 2000 NR 503 WEEK 8 FINAL EXAM QUESTIONS AND ANSWERS 100% CORRECTLY/VERIFIED BEST GRADED A+ GUARANTEED SUCCESS LATEST UPDATE 2022 49 years, & 237.35 deaths for those 50 years or more. The total number of deaths expected in 2005 based on this pooled rate is 558.98. Therefore, the age-adjusted overall rate for 2005 is 558.98 deaths divided by 240,000 persons. In 2001, a state enacted a law that required the use of safety seats for all children under 7 years of age & m&atory seatbelt use for all persons. The table below lists the number of deaths due to motor vehicle accidents (MVAs) & the total population by age in 2000 (before the law) & 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: 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? NR 503 WEEK 8 FINAL EXAM QUESTIONS AND ANSWERS 100% CORRECTLY/VERIFIED BEST GRADED A+ GUARANTEED SUCCESS LATEST UPDATE 2022 Children ages 5 to 9 had the highest rate of death in all periods The case-fatality rate is high The duration of disease is short A mortality rate is an example of an incidence rate NR 503 WEEK 8 FINAL EXAM QUESTIONS AND ANSWERS 100% CORRECTLY/VERIFIED BEST GRADED A+ GUARANTEED SUCCESS LATEST UPDATE 2022 Based on the information above, one may conclude: Which of the following characteristics indicate that mortality rates provide a reliable estimate of disease incidence? More than one answer may be correct. Which of the following statements are true? More than one answer may be correct. 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 NR 503 WEEK 8 FINAL EXAM QUESTIONS AND ANSWERS 100% CORRECTLY/VERIFIED BEST GRADED A+ GUARANTEED SUCCESS LATEST UPDATE 2022 NR 503 WEEK 8 FINAL EXAM QUESTIONS AND ANSWERS 100% CORRECTLY/VERIFIED BEST GRADED A+ GUARANTEED SUCCESS LATEST UPDATE 2022 same time period. It was concluded from these data that 25-year- NR 503 WEEK 8 FINAL EXAM QUESTIONS AND ANSWERS 100% CORRECTLY/VERIFIED BEST GRADED A+ GUARANTEED SUCCESS LATEST UPDATE 2022 Incidence rates will be equal to mortality rates Incorrect because rates are not reported The case-fatality rate is lower for women NR 503 WEEK 8 FINAL EXAM QUESTIONS AND ANSWERS 100% CORRECTLY/VERIFIED BEST GRADED A+ GUARANTEED SUCCESS LATEST UPDATE 2022 olds with more driving experience have increased accidents compared to those who started driving later. This conclusion is: For a disease such as liver cancer, which is highly fatal & of short duration, which of the following statements is true? Choose the best answer. The prevalence rate of a disease is two times greater in women than in men, but the incidence rates are the same in men & women. Which of the following statements may explain this situation? NR 503 WEEK 8 FINAL EXAM QUESTIONS AND ANSWERS 100% CORRECTLY/VERIFIED BEST GRADED A+ GUARANTEED SUCCESS LATEST UPDATE 2022 NR 503 WEEK 8 FINAL EXAM QUESTIONS AND ANSWERS 100% CORRECTLY/VERIFIED BEST GRADED A+ GUARANTEED SUCCESS LATEST UPDATE 2022 have the condition, or 90 cases (60% sensitivity multiplied by 150 myopic children). Further, the school nurse will incorrectly identify 170 false positive cases of myopia among those who do not have the condition (80% specificity multiplied by 850 non- myopic children). The sum of the cases labeled as positive by the school nurse equals 260 children (90 true myopic children plus 170 false positive children). A school nurse examined a population of 1,000 children in an attempt to detect nearsightedness. The prevalence of myopia in this population is known to be 15%. The sensitivity of the examination is 60% & its specificity is 80%. All children labeled as “positive” (i.e., suspected of having myopia) by the school nurse are sent for examination by an optometrist. The sensitivity of the optometrist’s examination is 98% & its specificity is 90%. What is the positive predictive value (PPV) of the school nurse’s exam? The PPV of the school nurse’s exam is equal to the number of true positive cases divided by the total number of those that the school nurse labels as positive. In this exam, the PPV is 34.6% (90 true myopic children divided by 260 children labeled as myopic by the school nurse). A school nurse examined a population of 1,000 children in an attempt to detect nearsightedness. The prevalence of myopia in this population is known to be 15%. The sensitivity of the examination is 60% & its specificity is 80%. All children labeled as “positive” (i.e., suspected of having myopia) by the school NR 503 WEEK 8 FINAL EXAM QUESTIONS AND ANSWERS 100% CORRECTLY/VERIFIED BEST GRADED A+ GUARANTEED SUCCESS LATEST UPDATE 2022 NR 503 WEEK 8 FINAL EXAM QUESTIONS AND ANSWERS 100% CORRECTLY/VERIFIED BEST GRADED A+ GUARANTEED SUCCESS LATEST UPDATE 2022 nurse are sent for examination by an optometrist. The sensitivity of the optometrist’s examination is 98% & its specificity is 90%. How many children will be labeled myopic following the optometrist’s exam? Since the optometrist will only test children who have been labeled as myopic by the school nurse, the testing group for this sequential exam is 260 children. The optometrist labels 105 children as myopic. Among the 90 myopic children correctly referred by the school nurse, the optometrist identifies 88 of NR 503 WEEK 8 FINAL EXAM QUESTIONS AND ANSWERS 100% CORRECTLY/VERIFIED BEST GRADED A+ GUARANTEED SUCCESS LATEST UPDATE 2022 NR 503 WEEK 8 FINAL EXAM QUESTIONS AND ANSWERS 100% CORRECTLY/VERIFIED BEST GRADED A+ GUARANTEED SUCCESS LATEST UPDATE 2022 them as myopic (98% sensitivity multiplied by 90 true cases of myopia). Further, the optometrist will incorrectly identify 17 false positive cases among the 170 children referred by the school nurse who do not have myopia. The sum of the cases labeled as positive by the optometrist equals 105 children (89 true cases plus 17 false positive cases). A school nurse examined a population of 1,000 children in an attempt to detect nearsightedness. The prevalence of myopia in this population is known to be 15%. The sensitivity of the examination is 60% & its specificity is 80%. All children labeled as “positive” (i.e., suspected of having myopia) by the school nurse are sent for examination by an optometrist. The sensitivity of the optometrist’s examination is 98% & its specificity is 90%. What is the positive predictive value (PPV) of the optometrist’s exam? The PPV of the optometrist’s exam is equal to the number of true positive cases divided by the total number that the optometrist labels as positive. The optometrist will only test 260 children referred by the school nurse. Of these children, the optometrist will correctly identify 89 cases of myopia among 105 children labeled as positive for the condition. The PPV equals 83.8% (89 true myopic children divided by 105 children labeled as positive). A school nurse examined a population of 1,000 children in an attempt to detect nearsightedness. The prevalence of myopia in this population is known to be 15%. The sensitivity of the examination is 60% & its specificity is 80%. All NR 503 WEEK 8 FINAL EXAM QUESTIONS AND ANSWERS 100% CORRECTLY/VERIFIED BEST GRADED A+ GUARANTEED SUCCESS LATEST UPDATE 2022 NR 503 WEEK 8 FINAL EXAM QUESTIONS AND ANSWERS 100% CORRECTLY/VERIFIED BEST GRADED A+ GUARANTEED SUCCESS LATEST UPDATE 2022 The overall specificity of the sequential exams is 98%; 833 children will be correctly labeled as negative for myopia among the 850 true negative cases. This is found by summing the number of true positives after each exam (680 following that of the school nurse plus 153 following the optometrist) & dividing by the true negative children in the population. This equals 833 divided by 850, or 98%. A school nurse examined a population of 1,000 children in an attempt to detect nearsightedness. The prevalence of myopia in this population is known to be 15%. The sensitivity of the examination is 60% & its specificity is 80%. All children labeled as “positive” (i.e., suspected of having myopia) by the school nurse are sent for examination by an optometrist. The sensitivity of the optometrist’s examination is 98% & its specificity is 90%. What would be the positive predictive value (PPV) of the exam for myopia if the optometrist tested all 1,000 children? The PPV of the optometrist’s exam would be equal to the number of true positive cases divided by all children labeled positive by the optometrist. Applying the sensitivity & specificity of the optometrist’s exam to the 1,000 children would indicate that 147 true positive cases are labeled positive by the optometrist. Additionally, the optometrist would find 85 false positive cases (850 true negative cases multiplied by 90% specificity). The PPV would be 63.4% (147 true positive cases divided by 232 total positives indicated by the optometrist). NR 503 WEEK 8 FINAL EXAM QUESTIONS AND ANSWERS 100% CORRECTLY/VERIFIED BEST GRADED A+ GUARANTEED SUCCESS LATEST UPDATE 2022 NR 503 WEEK 8 FINAL EXAM QUESTIONS AND ANSWERS 100% CORRECTLY/VERIFIED BEST GRADED A+ GUARANTEED SUCCESS LATEST UPDATE 2022 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 & averaging the results Insuring that the instrument is st&ardized before each sample is analyzed (All of the above) 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- & 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. What is the sensitivity of the PSA screening test in the combined groups? The sensitivity equals the number of true positives detected among all true positives. Since a biopsy is the gold st&ard test for prostate cancer, all 1,500 men in group A are positive for prostate cancer. The PSA test indicated that NR 503 WEEK 8 FINAL EXAM QUESTIONS AND ANSWERS 100% CORRECTLY/VERIFIED BEST GRADED A+ GUARANTEED SUCCESS LATEST UPDATE 2022 NR 503 WEEK 8 FINAL EXAM QUESTIONS AND ANSWERS 100% CORRECTLY/VERIFIED BEST GRADED A+ GUARANTEED SUCCESS LATEST UPDATE 2022 1,155 of these men had prostate cancer, a sensitivity of 77%. 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- & 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. What is the specificity of the screening test in the combined groups? NR 503 WEEK 8 FINAL EXAM QUESTIONS AND ANSWERS 100% CORRECTLY/VERIFIED BEST GRADED A+ GUARANTEED SUCCESS LATEST UPDATE 2022 NR 503 WEEK 8 FINAL EXAM QUESTIONS AND ANSWERS 100% CORRECTLY/VERIFIED BEST GRADED A+ GUARANTEED SUCCESS LATEST UPDATE 2022 Two neurologists, Drs. J & 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. NR 503 WEEK 8 FINAL EXAM QUESTIONS AND ANSWERS 100% CORRECTLY/VERIFIED BEST GRADED A+ GUARANTEED SUCCESS LATEST UPDATE 2022 62.9% 24.9% NR 503 WEEK 8 FINAL EXAM QUESTIONS AND ANSWERS 100% CORRECTLY/VERIFIED BEST GRADED A+ GUARANTEED SUCCESS LATEST UPDATE 2022 Based on the above information, the overall percent agreement between the two doctors including all observations is: Two neurologists, Drs. J & 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. What is the estimate of kappa for the reliability of the two doctors’ test results? NR 503 WEEK 8 FINAL EXAM QUESTIONS AND ANSWERS 100% CORRECTLY/VERIFIED BEST GRADED A+ GUARANTEED SUCCESS LATEST UPDATE 2022 Between 90% & 95% NR 503 WEEK 8 FINAL EXAM QUESTIONS AND ANSWERS 100% CORRECTLY/VERIFIED BEST GRADED A+ GUARANTEED SUCCESS LATEST UPDATE 2022 This table represents the results of coronary magnetic resonance (CMR) angiography compared to x- ray angiography (the gold st&ard 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 approximately 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: This table represents the results of coronary magnetic resonance (CMR) angiography compared to x- ray angiography (the gold st&ard 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 NR 503 WEEK 8 FINAL EXAM QUESTIONS AND ANSWERS 100% CORRECTLY/VERIFIED BEST GRADED A+ GUARANTEED SUCCESS LATEST UPDATE 2022 None of the above NR 503 WEEK 8 FINAL EXAM QUESTIONS AND ANSWERS 100% CORRECTLY/VERIFIED BEST GRADED A+ GUARANTEED SUCCESS LATEST UPDATE 2022 fatality rate (CFR) from TB during 2005? The CFR is the number of cause-specific deaths divided by all cases of the specific disease. In this example, 45,000 TB deaths occurred in 135,000 persons with TB. This equals a CFR of 33%. 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. What is the proportionate mortality ratio (PMR) for TB during 2005? The PMR is the number of deaths due to a specific cause divided by all deaths. In this example, the PMR equals 45,000 TB deaths divided by 175,000 deaths, or approximately 26%. 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? NR 503 WEEK 8 FINAL EXAM QUESTIONS AND ANSWERS 100% CORRECTLY/VERIFIED BEST GRADED A+ GUARANTEED SUCCESS LATEST UPDATE 2022 Is generally closer to observed survival rates in younger age groups NR 503 WEEK 8 FINAL EXAM QUESTIONS AND ANSWERS 100% CORRECTLY/VERIFIED BEST GRADED A+ GUARANTEED SUCCESS LATEST UPDATE 2022 Which of the following statements pertains to relative survival? NR 503 WEEK 8 FINAL EXAM QUESTIONS AND ANSWERS 100% CORRECTLY/VERIFIED BEST GRADED A+ GUARANTEED SUCCESS LATEST UPDATE 2022 NR 503 WEEK 8 FINAL EXAM QUESTIONS AND ANSWERS 100% CORRECTLY/VERIFIED BEST GRADED A+ GUARANTEED SUCCESS LATEST UPDATE 2022 What was the probability of surviving the second year given survival to the end of the first year? The probability of surviving the second year given survival to the end of the year indicates that we are concerned with the survival proportion of those alive at the end of year 1. In this example, we have 950 persons alive at the beginning of year 2 (thus, the end of year 1). Of this group, 30 die by the end of the second year. This gives a survival rate of 920 divided by 950, or 97%. What was the cumulative probability of surviving after only 2 years of follow-up? The cumulative survival is the total number of those surviving by the end of the second year divided by all persons who were alive at the beginning of follow-up. In this example, there were 920 survivors among the 1,000 persons who were alive at the beginning of observation. This equals a cumulative survival of 92%. Alternatively, this cumulative survival can be calculated by multiplying the survival rates for each period of interest. In this example 95% survival for year 1 multiplied by 97% survival for year 2 equals a cumulative survival of 92%. An important assumption in this type of analysis is that: NR 503 WEEK 8 FINAL EXAM QUESTIONS AND ANSWERS 100% CORRECTLY/VERIFIED BEST GRADED A+ GUARANTEED SUCCESS LATEST UPDATE 2022 The risk of disease does not change within each interval over the period of observation Median survival time NR 503 WEEK 8 FINAL EXAM QUESTIONS AND ANSWERS 100% CORRECTLY/VERIFIED BEST GRADED A+ GUARANTEED SUCCESS LATEST UPDATE 2022 Which of the following is a measure of disease prognosis? In 2003, Sudden Acute Respiratory Syndrome (SARS) appeared in several countries, mainly in Asia. The disease was determined to have been caused by a virus that could be spread from person –to person from the index case NR 503 WEEK 8 FINAL EXAM QUESTIONS AND ANSWERS 100% CORRECTLY/VERIFIED BEST GRADED A+ GUARANTEED SUCCESS LATEST UPDATE 2022 NR 503 WEEK 8 FINAL EXAM QUESTIONS AND ANSWERS 100% CORRECTLY/VERIFIED BEST GRADED A+ GUARANTEED SUCCESS LATEST UPDATE 2022 occurring in mainl& China. This table reflects the total number of reported cases of SARS & deaths among those cases as best as can be determined. What is the overall case-fatality rate for the worldwide epidemic of SARS? NR 503 WEEK 8 FINAL EXAM QUESTIONS AND ANSWERS 100% CORRECTLY/VERIFIED BEST GRADED A+ GUARANTEED SUCCESS LATEST UPDATE 2022 9.5% Is almost one half that of the case-fatality rate in Singapore NR 503 WEEK 8 FINAL EXAM QUESTIONS AND ANSWERS 100% CORRECTLY/VERIFIED BEST GRADED A+ GUARANTEED SUCCESS LATEST UPDATE 2022 In 2003, Sudden Acute Respiratory Syndrome (SARS) appeared in several countries, mainly in Asia. The disease was determined to have been caused by a virus that could be spread from person –to person from the index case occurring in mainl& China. This table reflects the total number of reported cases of SARS & deaths among those cases as best as can be determined. Based on the table, we can conclude that the case-fatality rate (CFR) in Vietnam: In 2003, Sudden Acute Respiratory Syndrome (SARS) appeared in several countries, mainly in Asia. The disease was determined to have been caused by a virus that could be spread from person –to person from the index case occurring in mainl& China. This table reflects the total number of reported cases of SARS & deaths among those cases as best as can be determined. Following a revision in the case definition, more persons were found to have suffered from an infection with the SARS virus. The inclusion of these cases, almost all asymptomatic, did not impact the total number of SARS fatalities. What NR 503 WEEK 8 FINAL EXAM QUESTIONS AND ANSWERS 100% CORRECTLY/VERIFIED BEST GRADED A+ GUARANTEED SUCCESS LATEST UPDATE 2022 NR 503 WEEK 8 FINAL EXAM QUESTIONS AND ANSWERS 100% CORRECTLY/VERIFIED BEST GRADED A+ GUARANTEED SUCCESS LATEST UPDATE 2022 Column (B) from top to bottom: 248, 124, 55 Column (E) from top to bottom: 0.410, 0.470, 0.296 Column (F) from top to bottom: 0.590, 0.530, 0.704 Column (G) from top to bottom: 0.590, 0.313, 0.220 Therefore, the second year survival probability among all those surviving in the study past the first year is 53%. The probability of dying during the second year equals the number of deaths during the interval (55) divided by the total number of persons alive at the start of the interval less one half of those withdrawing from the study (117). Subtracting this value from 100% results in a survival rate of 53% for the interval. For all people in the study, what is the probability of surviving to the end of the second year? The cumulative probability of survival through the second year equals the probability of survival for the first year multiplied by the probability for the second year. This equals 59% multiplied by 53%, or 31.3%. What is the probability chance of surviving 3 years after diagnosis? NR 503 WEEK 8 FINAL EXAM QUESTIONS AND ANSWERS 100% CORRECTLY/VERIFIED BEST GRADED A+ GUARANTEED SUCCESS LATEST UPDATE 2022 NR 503 WEEK 8 FINAL EXAM QUESTIONS AND ANSWERS 100% CORRECTLY/VERIFIED BEST GRADED A+ GUARANTEED SUCCESS LATEST UPDATE 2022 The cumulative survival probability for all 3 years equals the product of the independent interval survival probabilities. In this example, 59% multiplied by 53% multiplied by 70.4% gives a cumulative survival probability of 22%. What is the total number of person-years of follow-up for patients in the study assuming a median survival time of one half of the year for all persons dying during an interval & an observation time of one half of the year for all persons withdrawing from the study? This calculation involves attributing the correct amounts of person-years to each group during an interval. For the first year of the study, 96 deaths occur. Using the median survival time, we can calculate that these persons contributed 48 person-years of observation. Additionally, 28 persons withdraw from the study. Again, allocating one half of the year to each of these patients results in 14 person-years. Of the remaining 124 persons who survive for the full year, they contribute 124 person-years of observation. The total person-time for the first year of the study is 186 person-years. Continuing with this same approach for years 2 & 3 of the study, we arrive at a total of 321.5 person-years of observed study time. Before reporting the results of this survival analysis, the investigators compared baseline characteristics of the 44 people who withdrew from the study before its end to those who had complete follow-up. This was done: NR 503 WEEK 8 FINAL EXAM QUESTIONS AND ANSWERS 100% CORRECTLY/VERIFIED BEST GRADED A+ GUARANTEED SUCCESS LATEST UPDATE 2022 To check whether those withdrawing from the study are similar to persons remaining in the study NR 503 WEEK 8 FINAL EXAM QUESTIONS AND ANSWERS 100% CORRECTLY/VERIFIED BEST GRADED A+ GUARANTEED SUCCESS LATEST UPDATE 2022 Chapters 7-8 NR 503 WEEK 8 FINAL EXAM QUESTIONS AND ANSWERS 100% CORRECTLY/VERIFIED BEST GRADED A+ GUARANTEED SUCCESS LATEST UPDATE 2022 NR 503 WEEK 8 FINAL EXAM QUESTIONS AND ANSWERS 100% CORRECTLY/VERIFIED BEST GRADED A+ GUARANTEED SUCCESS LATEST UPDATE 2022 reduced the need for blood transfusions due to internal hemorrhage compared to the current treatment. The following table summarizes the results of her study: What is the number of persons who died in hospital in the study? NR 503 WEEK 8 FINAL EXAM QUESTIONS AND ANSWERS 100% CORRECTLY/VERIFIED BEST GRADED A+ GUARANTEED SUCCESS LATEST UPDATE 2022 28 Reduces the potential for selection bias in allocation of treatment group NR 503 WEEK 8 FINAL EXAM QUESTIONS AND ANSWERS 100% CORRECTLY/VERIFIED BEST GRADED A+ GUARANTEED SUCCESS LATEST UPDATE 2022 A new drug treatment for cardiac thrombus claims to have a higher success rate than the current drug. A strong sign of the potential success is the lack of internal hemorrhaging starting 2 days after treatment. 168 patients who require treatment for cardiac thrombi are r&omized after agreeing to participate in a trial of the new drug. The researchers were interested in whether the new drug reduced the need for blood transfusions due to internal hemorrhage compared to the current treatment. The following table summarizes the results of her study: What is the main advantage of the r&omization of the 168 study participants to one of the two drug treatment groups? A new drug treatment for cardiac thrombus claims to have a higher success rate than the current drug. A strong sign of the potential success is the lack of internal hemorrhaging starting 2 days after treatment. 168 patients who require NR 503 WEEK 8 FINAL EXAM QUESTIONS AND ANSWERS 100% CORRECTLY/VERIFIED BEST GRADED A+ GUARANTEED SUCCESS LATEST UPDATE 2022 Correct 68.8% NR 503 WEEK 8 FINAL EXAM QUESTIONS AND ANSWERS 100% CORRECTLY/VERIFIED BEST GRADED A+ GUARANTEED SUCCESS LATEST UPDATE 2022 treatment for cardiac thrombi are r&omized after agreeing to participate in a trial of the new drug. The researchers were interested in whether the new drug reduced the need for blood transfusions due to internal hemorrhage compared to the current treatment. The following table summarizes the results of her study: The researchers interpret the findings to conclude that the new drug treatment is more likely to result in a blood transfusion & subsequent death. This statement is: A r&omized, double-blind clinical trial of a varicella vaccine observed an estimated incidence of 25% chickenpox episodes in persons receiving the vaccine, compared to 80% among persons receiving a placebo. The estimated efficacy of the vaccine is: NR 503 WEEK 8 FINAL EXAM QUESTIONS AND ANSWERS 100% CORRECTLY/VERIFIED BEST GRADED A+ GUARANTEED SUCCESS LATEST UPDATE 2022 R&omization was successful since the investigators did not alter the selection of participants in either group in order to ensure equal percentages of men NR 503 WEEK 8 FINAL EXAM QUESTIONS AND ANSWERS 100% CORRECTLY/VERIFIED BEST GRADED A+ GUARANTEED SUCCESS LATEST UPDATE 2022 men, while 80% of those in the drug X group were men. Which statement is most likely to be true? A multicenter double-blind r&omized study was carried out to compare the effect of drug X with that of a placebo in patients surviving acute myocardial infarction (AMI). Treatment with the drug started 7 days after infarction in 1,884 patients, 52% of all persons who were evaluated for entry into the study. 945 participants were r&omized to treatment with drug X while 939 were assigned to the placebo group. Patients were then followed for 12 months for reinfarction. There were 152 deaths in the placebo group & 98 in the group receiving drug X. A preliminary analysis was conducted after 6 months & found that 87% of participants in the placebo group & 85% of those in the drug X group had taken more than 90% of their prescribed dosages. Which statement best describes this finding? NR 503 WEEK 8 FINAL EXAM QUESTIONS AND ANSWERS 100% CORRECTLY/VERIFIED BEST GRADED A+ GUARANTEED SUCCESS LATEST UPDATE 2022 The characteristics of patients who failed to comply with the treatment dosages should be assessed as they may differ from those who complied NR 503 WEEK 8 FINAL EXAM QUESTIONS AND ANSWERS 100% CORRECTLY/VERIFIED BEST GRADED A+ GUARANTEED SUCCESS LATEST UPDATE 2022 A multicenter double-blind r&omized study was carried out to compare the effect of drug X with that of a placebo in patients surviving acute myocardial infarction (AMI). Treatment with the drug started 7 NR 503 WEEK 8 FINAL EXAM QUESTIONS AND ANSWERS 100% CORRECTLY/VERIFIED BEST GRADED A+ GUARANTEED SUCCESS LATEST UPDATE 2022 Double blinding ensures that potential biases regarding selection, follow-up, & analysis can be reduced NR 503 WEEK 8 FINAL EXAM QUESTIONS AND ANSWERS 100% CORRECTLY/VERIFIED BEST GRADED A+ GUARANTEED SUCCESS LATEST UPDATE 2022 days after infarction in 1,884 patients, 52% of all persons who were evaluated for entry into the study. 945 participants were r&omized to treatment with drug X while 939 were assigned to the placebo group. Patients were then followed for 12 months for reinfarction. There were 152 deaths in the placebo group & 98 in the group receiving drug X. Which of the following statements best describes the reason for conducting the study as a double- blind trial? A multicenter double-blind r&omized study was carried out to compare the effect of drug X with that of a placebo in patients surviving acute myocardial infarction (AMI). Treatment with the drug started 7 days after infarction in 1,884 patients, 52% of all persons who were evaluated for entry into the study. 945 participants were r&omized to treatment with drug X while 939 were assigned to the placebo group. Patients were then followed for 12 months for reinfarction. There were 152 deaths in the placebo group & 98 in the group receiving drug X. NR 503 WEEK 8 FINAL EXAM QUESTIONS AND ANSWERS 100% CORRECTLY/VERIFIED BEST GRADED A+ GUARANTEED SUCCESS LATEST UPDATE 2022 Group QS NR 503 WEEK 8 FINAL EXAM QUESTIONS AND ANSWERS 100% CORRECTLY/VERIFIED BEST GRADED A+ GUARANTEED SUCCESS LATEST UPDATE 2022 group QS who received quitting brochures as well as social support brochures listing benefits of smoking cessation, & telephone support group T who received the brochures & a monthly phone call from a counselor. Participants received mailed surveys at 8, 16, & 24 months after r&omization. The results after 2 years are in the table below. Which group had the least success in terms of quitting smoking? The following data come from a study of approaches to smoking cessation. Smokers who want to quit were r&omized to one of four groups: control group C who received no intervention assistance, quitting guide group Q who received brochures about how to quit smoking, quitting guide & support group QS who received quitting brochures as well as social support brochures listing benefits of smoking cessation, & telephone support group T who received the brochures & a monthly phone call from a counselor. Participants received mailed surveys at 8, 16, & 24 months after r&omization. The results after 2 years are in the table below. What is the main purpose of r&omization in this study? NR 503 WEEK 8 FINAL EXAM QUESTIONS AND ANSWERS 100% CORRECTLY/VERIFIED BEST GRADED A+ GUARANTEED SUCCESS LATEST UPDATE 2022 To avoid assigning more persons who have tried & failed to quit in the past to the control group The need to obtain data on the incidence of early fetal losses due to congenital birth defects NR 503 WEEK 8 FINAL EXAM QUESTIONS AND ANSWERS 100% CORRECTLY/VERIFIED BEST GRADED A+ GUARANTEED SUCCESS LATEST UPDATE 2022 Chapters 9-15 A study is planned to investigate the relationship of factors associated with maternal hypertension & the risk of congenital birth defects in children born to these women. Which of the following would be a reason for using a cohort study design? A researcher is interested in the etiology of myocardial infarction (MI) among men between 18 & 40 years of age. Her hypothesis concerns the influence of diets high in fat & subsequent development of MI. What is the best study approach to address this hypothesis? NR 503 WEEK 8 FINAL EXAM QUESTIONS AND ANSWERS 100% CORRECTLY/VERIFIED BEST GRADED A+ GUARANTEED SUCCESS LATEST UPDATE 2022 Prospective cohort study identifying a population of men in this age group, administering a dietary survey & classifying men by high & low fat diet, then following both groups for the development of an MI NR 503 WEEK 8 FINAL EXAM QUESTIONS AND ANSWERS 100% CORRECTLY/VERIFIED BEST GRADED A+ GUARANTEED SUCCESS LATEST UPDATE 2022 Which of the following is an advantage to the conduct of a cohort study? NR 503 WEEK 8 FINAL EXAM QUESTIONS AND ANSWERS 100% CORRECTLY/VERIFIED BEST GRADED A+ GUARANTEED SUCCESS LATEST UPDATE 2022 NR 503 WEEK 8 FINAL EXAM QUESTIONS AND ANSWERS 100% CORRECTLY/VERIFIED BEST GRADED A+ GUARANTEED SUCCESS LATEST UPDATE 2022 What are the rates of cancer incidence in each exposure group? The rate of cancer incidence in the x-ray exposed group is 15 per 1,000 (49 divided by 3,263 multiplied by 1,000) & 7 per 1,000 in the nonexposed group (47 divided by 6,737 multiplied by 1,000). In a study of the adverse effects of x-rays among children, a retrospective cohort study was done using records from several large children’s hospitals for the period of 1980 to 1985. 10,000 children were NR 503 WEEK 8 FINAL EXAM QUESTIONS AND ANSWERS 100% CORRECTLY/VERIFIED BEST GRADED A+ GUARANTEED SUCCESS LATEST UPDATE 2022 NR 503 WEEK 8 FINAL EXAM QUESTIONS AND ANSWERS 100% CORRECTLY/VERIFIED BEST GRADED A+ GUARANTEED SUCCESS LATEST UPDATE 2022 selected as a representative population of ill children seen at the hospitals during that time. Subjects were classified according to whether or not they received an x-ray during their stay in the hospital & were followed from their hospital stay through 2005 for the development of cancer. During the follow- up period, 49 incident cancers occurred in 3,263 children who had received an x- ray, & 47 incident cancers occurred in the 6,737 children who had not received an x-ray during their hospitalization. What is the attributable risk of cancer due to x-ray in this study population? What is the interpretation of this estimate? The attributable risk equals the incidence rate in the exposed group minus the incidence rate in the nonexposed group. In this instance, the attributable risk is 8 per 1,000. This estimate is interpreted to mean that 8 of the 15 incident cases of cancer occurring in 1,000 children exposed to x-rays are due to the exposure itself. In a study of the adverse effects of x-rays among children, a retrospective cohort study was done using records from several large children’s hospitals for the period of 1980 to 1985. 10,000 children were selected as a representative population of ill children seen at the hospitals during that time. Subjects were classified according to whether or not they received an x-ray during their stay in the hospital & were followed from their hospital stay through 2005 for the development of cancer. During the follow- up period, 49 incident cancers NR 503 WEEK 8 FINAL EXAM QUESTIONS AND ANSWERS 100% CORRECTLY/VERIFIED BEST GRADED A+ GUARANTEED SUCCESS LATEST UPDATE 2022 NR 503 WEEK 8 FINAL EXAM QUESTIONS AND ANSWERS 100% CORRECTLY/VERIFIED BEST GRADED A+ GUARANTEED SUCCESS LATEST UPDATE 2022 occurred in 3,263 children who had received an x-ray, & 47 incident cancers occurred in the 6,737 children who had not received an x-ray during their hospitalization. What is the risk ratio for the effect of exposure on the development of cancer in this study? What is the interpretation of this estimated ratio? The risk ratio is found by dividing the rate of cancers for each exposure group. In this instance, 15 per 1,000 (0.015) divided by 7 per 1,000 (0.007) equals a risk ratio of 2.1. This indicates that the risk of cancer is twice as high in children who received x-rays during their stay in the hospital. In a study of the adverse effects of x-rays among children, a retrospective cohort study was done using records from several large children’s hospitals for the period of 1980 to 1985. 10,000 children were selected as a representative population of ill children seen at the hospitals during that time. Subjects were classified according to whether or not they received an x-ray during their stay in the hospital & were followed from their hospital stay through 2005 for the development of cancer. During the follow- up period, 49 incident cancers occurred in 3,263 children who had received an x-ray, & 47 incident cancers occurred in the 6,737 children who had not received an x-ray during their hospitalization. Which of the following issues should the investigators consider when interpreting whether a causal association exists between cancer incidence & NR 503 WEEK 8 FINAL EXAM QUESTIONS AND ANSWERS 100% CORRECTLY/VERIFIED BEST GRADED A+ GUARANTEED SUCCESS LATEST UPDATE 2022 5.00 Retrospective cohort study NR 503 WEEK 8 FINAL EXAM QUESTIONS AND ANSWERS 100% CORRECTLY/VERIFIED BEST GRADED A+ GUARANTEED SUCCESS LATEST UPDATE 2022 In 2002, investigators started a study of the association of cholesterol levels & stroke in a group of 2,000 healthy persons who had participated in a cholesterol screening program in 1992. The investigators determined exposure categories using cholesterol levels in all persons that were measured at the time of the screening program. A cutoff value of 200 mg/dL was used to define “high” cholesterol while those with levels below 200 were identified as having “low” cholesterol. Using this definition, 1,000 persons had “high” cholesterol levels while the remaining 1,000 persons had “low” cholesterol. The investigators determined that 150 cases of stroke occurred by the end of 2004, with 113 cases occurring in the high cholesterol group. What is the study design that the investigators used? In 2002, investigators started a study of the association of cholesterol levels & NR 503 WEEK 8 FINAL EXAM QUESTIONS AND ANSWERS 100% CORRECTLY/VERIFIED BEST GRADED A+ GUARANTEED SUCCESS LATEST UPDATE 2022 NR 503 WEEK 8 FINAL EXAM QUESTIONS AND ANSWERS 100% CORRECTLY/VERIFIED BEST GRADED A+ GUARANTEED SUCCESS LATEST UPDATE 2022 stroke in a group of 2,000 healthy persons who had participated in a cholesterol screening program in 1992. The investigators determined exposure categories using cholesterol levels in all persons that were measured at the time of the screening program. A cutoff value of 200 mg/dL was used to define “high” cholesterol while those with levels below 200 were identified as having “low” cholesterol. Using this definition, 1,000 persons had “high” cholesterol levels while the remaining 1,000 persons had “low” NR 503 WEEK 8 FINAL EXAM QUESTIONS AND ANSWERS 100% CORRECTLY/VERIFIED BEST GRADED A+ GUARANTEED SUCCESS LATEST UPDATE 2022 Relative risk 3.1 NR 503 WEEK 8 FINAL EXAM QUESTIONS AND ANSWERS 100% CORRECTLY/VERIFIED BEST GRADED A+ GUARANTEED SUCCESS LATEST UPDATE 2022 cholesterol. The investigators determined that 150 cases of stroke occurred by the end of 2004, with 113 cases occurring in the high cholesterol group. What type of risk measure should the investigators calculate? In 2002, investigators started a study of the association of cholesterol levels & stroke in a group of 2,000 healthy persons who had participated in a cholesterol screening program in 1992. The investigators determined exposure categories using cholesterol levels in all persons that were measured at the time of the screening program. A cutoff value of 200 mg/dL was used to define “high” cholesterol while those with levels below 200 were identified as having “low” cholesterol. Using this definition, 1,000 persons had “high” cholesterol levels while the remaining 1,000 persons had “low” cholesterol. The investigators determined that 150 cases of stroke occurred by the end of 2004, with 113 cases occurring in the high cholesterol group. Using the reported study data, what is the estimate of the risk measure that was chosen? NR 503 WEEK 8 FINAL EXAM QUESTIONS AND ANSWERS 100% CORRECTLY/VERIFIED BEST GRADED A+ GUARANTEED SUCCESS LATEST UPDATE 2022 1.3 31% NR 503 WEEK 8 FINAL EXAM QUESTIONS AND ANSWERS 100% CORRECTLY/VERIFIED BEST GRADED A+ GUARANTEED SUCCESS LATEST UPDATE 2022 The following data are from a prospective study that examined the relationship between smoking & incidence of both myocardial infarction (heart attack) & breast cancer among women. What is the proportion attributable risk of breast cancer among smokers? What is the relative risk of myocardial infarction for smokers? The following data are from a prospective study that examined the relationship between smoking & incidence of both myocardial infarction (heart attack) & breast cancer among women. If the proportion of smokers in this population is 30%, what is the population proportion attributable risk of breast cancer due to smoking? A researcher is interested in the etiology of cervical cancer among women between 18 & 35 years of age. Her hypothesis concerns the influence of sexually NR 503 WEEK 8 FINAL EXAM QUESTIONS AND ANSWERS 100% CORRECTLY/VERIFIED BEST GRADED A+ GUARANTEED SUCCESS LATEST UPDATE 2022 The ratio of the odds of exposure among cases & controls equal to 4.1 Case-control study of women 18 to 35 years of age identified with cervical cancer in the hospital (cases) compared to women admitted for other diseases (controls) NR 503 WEEK 8 FINAL EXAM QUESTIONS AND ANSWERS 100% CORRECTLY/VERIFIED BEST GRADED A+ GUARANTEED SUCCESS LATEST UPDATE 2022 transmitted diseases such as human papilloma virus (HPV) & subsequent development of cancer. What is the best study approach to address this hypothesis? Suppose that 350 cervical cancer cases were identified & a r&om sample of women of the same age range who were admitted to the hospital included 500 eligible controls. After independent blood tests of all cases & controls, 90% of cases were positive for HPV antibodies while 63% of controls were positive for antibodies to the virus. What is the appropriate ratio measure of association & its value? Suppose that one third of all cervical cancer cases were smokers as were one third of all controls & smoking status is independent of HPV infection. Is smoking a potential confounder in this study? NR 503 WEEK 8 FINAL EXAM QUESTIONS AND ANSWERS 100% CORRECTLY/VERIFIED BEST GRADED A+ GUARANTEED SUCCESS LATEST UPDATE 2022 No, the chance of being a smoker among women with cervical cancer is the same as that of being a smoker among women without cervical cancer NR 503 WEEK 8 FINAL EXAM QUESTIONS AND ANSWERS 100% CORRECTLY/VERIFIED BEST GRADED A+ GUARANTEED SUCCESS LATEST UPDATE 2022 NR 503 WEEK 8 FINAL EXAM QUESTIONS AND ANSWERS 100% CORRECTLY/VERIFIED BEST GRADED A+ GUARANTEED SUCCESS LATEST UPDATE 2022 NR 503 WEEK 8 FINAL EXAM QUESTIONS AND ANSWERS 100% CORRECTLY/VERIFIED BEST GRADED A+ GUARANTEED SUCCESS LATEST UPDATE 2022 A case-control study of the relationship between high-fat diet & diabetes was performed. The results of the study are shown below, stratified by gender. Based on the responses above, what is the most appropriate measure of association to present when reporting the results of this study? NR 503 WEEK 8 FINAL EXAM QUESTIONS AND ANSWERS 100% CORRECTLY/VERIFIED BEST GRADED A+ GUARANTEED SUCCESS LATEST UPDATE 2022 The separate stratum-specific odds ratios Effect modification by gender A subject selected as a control may later be selected as a case NR 503 WEEK 8 FINAL EXAM QUESTIONS AND ANSWERS 100% CORRECTLY/VERIFIED BEST GRADED A+ GUARANTEED SUCCESS LATEST UPDATE 2022 A case-control study of the relationship between high-fat diet & diabetes was performed. The results of the study are shown below, stratified by gender. Which of the following is demonstrated by the stratified odds ratio shown above? When incidence density sampling is used in a case-control study, which of the following is an important consideration? A recent prospective study on baldness & coronary heart disease (CHD) concluded that there was no association between the two, despite earlier cross- sectional studies which showed that baldness was associated with CHD when the two were determined at the same time in men. Which Bradford-Hill NR 503 WEEK 8 FINAL EXAM QUESTIONS AND ANSWERS 100% CORRECTLY/VERIFIED BEST GRADED A+ GUARANTEED SUCCESS LATEST UPDATE 2022 Temporality Selection bias NR 503 WEEK 8 FINAL EXAM QUESTIONS AND ANSWERS 100% CORRECTLY/VERIFIED BEST GRADED A+ GUARANTEED SUCCESS LATEST UPDATE 2022 criterion is being tested by the newer study? A study examined the relation between use of estrogen replacement therapy (ERT) & ovarian cancer mortality using a prospective design. Of 24,231 eligible women, none had a prior history of cancer, hysterectomy, or ovarian surgery at enrollment in 1982. During 12 years of follow-up, 44 deaths from ovarian cancer occurred. In the published results, the authors note that 12,543 were excluded from the original cohort due to missing information for prior history variables. Which of the following is of greatest concern when interpreting the study results? A study examined the relation between use of estrogen replacement therapy (ERT) & ovarian cancer mortality using a prospective design. Of 24,231 eligible women, none had a prior history of cancer, hysterectomy, or ovarian surgery NR 503 WEEK 8 FINAL EXAM QUESTIONS AND ANSWERS 100% CORRECTLY/VERIFIED BEST GRADED A+ GUARANTEED SUCCESS LATEST UPDATE 2022 To minimize recall bias of exposure Would result in differential classification of outcome NR 503 WEEK 8 FINAL EXAM QUESTIONS AND ANSWERS 100% CORRECTLY/VERIFIED BEST GRADED A+ GUARANTEED SUCCESS LATEST UPDATE 2022 interviews. Why was this done? An epidemiologist was interested in determining whether aspirin was associated with an increased risk of gastrointestinal (GI) bleeding. She relied on primary physicians to identify 600 patients at a hospital who were taking a daily dose of aspirin & 600 other patients who were not taking aspirin. Subjects were followed for 1 year to detect any occurrences of GI bleeding. Due to publicity about the risk of bleeding associated with aspirin, primary physicians treating patients at the hospital followed their patients who were taking aspirin more closely than they were unexposed subjects. Which of the following describes the impact that this may have on the epidemiologist’s study? An epidemiologist was interested in determining whether aspirin was associated with an increased risk of gastrointestinal (GI) bleeding. She relied on NR 503 WEEK 8 FINAL EXAM QUESTIONS AND ANSWERS 100% CORRECTLY/VERIFIED BEST GRADED A+ GUARANTEED SUCCESS LATEST UPDATE 2022 NR 503 WEEK 8 FINAL EXAM QUESTIONS AND ANSWERS 100% CORRECTLY/VERIFIED BEST GRADED A+ GUARANTEED SUCCESS LATEST UPDATE 2022 primary physicians to identify 600 patients at a hospital who were taking a daily dose of aspirin & 600 other patients who were not taking aspirin. Subjects were followed for 1 year to detect any occurrences of GI bleeding. Due to publicity about the risk of bleeding associated with aspirin, primary physicians treating patients at the hospital followed their patients who were taking aspirin more closely than they were unexposed subjects. Suppose that the study was repeated with a second physician who was responsible for verifying a NR 503 WEEK 8 FINAL EXAM QUESTIONS AND ANSWERS 100% CORRECTLY/VERIFIED BEST GRADED A+ GUARANTEED SUCCESS LATEST UPDATE 2022 The bias would decrease toward the null Variables associated with the outcome under study are controlled for in both the case & control groups NR 503 WEEK 8 FINAL EXAM QUESTIONS AND ANSWERS 100% CORRECTLY/VERIFIED BEST GRADED A+ GUARANTEED SUCCESS LATEST UPDATE 2022 diagnosis of GI bleeding in the patients. This physician was informed that all patients were using aspirin. If the likelihood of diagnosing the outcome among unexposed subjects was increased while all other diagnostic probabilities remained the same, what impact would this have on the bias? Matching is employed in a case-control study in order to ensure that: The effect of exposure to high-density automobile traffic either as a bicyclist or pedestrian was compared to minimal or no exposure to automobile traffic. It is hypothesized that direct exposure to automobile traffic has an effect on acute myocardial infarction (MI). This association was studied with 500 incident cases of MI diagnosed in the emergency rooms of several hospitals & compared to 1,000 other subjects who visited the same emergency rooms for reasons other NR 503 WEEK 8 FINAL EXAM QUESTIONS AND ANSWERS 100% CORRECTLY/VERIFIED BEST GRADED A+ GUARANTEED SUCCESS LATEST UPDATE 2022