Epi Mid Term + Final Practice Questions
Larimer County had the 12th highest opioid-related death rate in Colorado during 2013 to 2015. From January 1, 2013- December 31, 2015, there were 68 opioid-related deaths among the 219 individuals that were hospitalized for opioid exposure. What was the case-fatality among Larimer County residents that had been hospitalized due to opioid use during this time period? Give your answer as a proportion rounded to two decimal places (example: 0.99)
0.31 Case fatality = 68 deaths / 219 hospitalizations for opioid related issue = 31% or 0.31
What is the Standardized Mortality Ratio (SMR) of esophageal cancer in New Mexico compared to the population in the U.S., while accounting for age? Please round your answer to the 100th decimal place.
0.36 3840 / 10,763 = 0.3567 = 0.36.
What is the stratified OR for high stress and severe acne among the <20yr olds? Please round your answer rounded to the 100th decimal place.
1.56 OR = (147*84)/(63*126) = 1.56
What is the total number of expected esophageal cancer cases for the New Mexico population if the U.S. age-adjusted cancer mortality rates are applied in New Mexico? Please round your answer to the nearest integer (whole number).
10,763 0-14 --> (5 * 828,663) / 100,000 = 41 15-49 --> (23 * 893,809) / 100,000 = 206 50 - 69 --> (335 * 810,632) / 100,000 = 2716 70+ --> (1294 * 602,768) / 100,000 = 7800 41 + 206 + 2,716 + 7,800 = 10,763
At your new state health department job, you are tasked with determining the crude mortality in the state last year. Census 2020 data reveled that at the beginning of the year the state population was 13,023,456. Use data on migration patterns, births, and deaths, state demographers estimated the midyear population to be 12,335,000. In 2020, the state experienced 131,044 deaths. What was the mortality density rate per 1,000 person years in 2020? Please round your answer to 2 decimal places.
10.62 131,044/12,335,000 = 10.62 deaths per 1000 person years
A cohort study investigated the effect of alcohol and cannabis consumption on risk of injury. The RRs determined in this study are given in the table below. Mark all statements that are true.
Alcohol users that did not use cannabis were at the highest risk. Alcohol users that did not use cannabis were 2.22 times as likely to be injured.
In vaccine research and development, which phase emphasizes preliminary understanding of safety within healthy populations?
Phase 1
Suppose 100 people are exposed to a toxic chemical and are observed for 1 month. During the month, 30 of the 100 people die. Match the values of ratios and proportions/percentages that can be calculated at the end of the month to compare the dead to the living.
Ratio to Living 3:7 Proportion Living 70%
OBJECTIVE: This study evaluated the association between group A streptococcal (GAS) infections and the risks of developing tic disorders, obsessive-compulsive disorder (OCD), and attentiondeficit/hyperactivity disorder (ADHD). METHODS: We conducted a prospective cohort study in 2014 using Taiwan's National Health Insurance Research Database. The study cohort consisted of patients younger than 18 years with newly diagnosed GAS infection (ICD-9-CM codes 034 [streptococcal sore throat and scarlet fever] and 482.31 [pneumonia due to Streptococcus, group A]) from 2001 to 2010. All patients having GAS infection codes between 1996 and 2000 were excluded. We assessed the patients' risks of developing tic disorders, OCD, and ADHD (ICD-9-CM codes 300.3 [obsessive-compulsive disorders], 301.4 [obsessive-compulsive personality disorder], 307.2 [tic disorder, unspecified], and 314 [attention deficit disorder]) and compared these risks with those of an unexposed cohort. The primary outcomes of this study were the overall neuropsychiatric disorder occurrence and the occurrence of separate subtypes. RESULTS: We examined 2,596 patients and 25,960 controls. The incidence of neuropsychiatric disorders in the GAS infection cohort was 60.42 per 10,000 person-years and 49.32 per 10,000 person-years in the unexposed cohort. What is the best measure of association to calculate given the information in the abstract above?
risk ratio
What is the best measure of association to use to examine the exposure disease relationship for the study described? (Choose the best answer).
risk ratio
The use of PSA (prostate specific antigen) test of blood samples among men over the age of 50 to detect prostate cancer among asymptomatic men would be defined as: (Choose the one best answer)
secondary prevention
Which type of bias can occur in cohort and experimental studies from differential losses to follow-up?
selection bias
Given the metrics you computed in Question 4 - Question 9, which measure(s) of association best represents the relationship between high stress and severe acne in this example? (choose one best answer)
stratified
You have assessed the role of gender in the relationship between exposure to Whopper hamburgers and coronary heart failure and have produced the following estimates: Crude OR= 2.4 Strata-specific OR(male) = 4.3, OR(female)= 1.4 M-H Adjusted OR = 2.3
stratified odds ratios based on gender
By assessing JUST the information below, which of Hill's Criteria for Causality may be met with this finding: (Choose one best answer) The risk of lung cancer was 18 times greater among smokers compared to non-smokers.
strength of association
Provide an answer to the above for secondary prevention:
1. Secondary disease is reducing the impact or spread after it has occurred, so in relation to COVID19 making sure close contacts like friends, family, or coworkers don't develop the illness. 2.Some examples of secondary prevention can include isolation, quarantine, and wearing a mask.
Provide an answer to the above for tertiary prevention
1. Tertiary prevention is reducing the potential of lasting effects. 2.In terms of COVID19 there are people that develop cardiac, neurological, or respiratory issues after having the illness. Things that can reduce lasting effects can include going to the doctor and getting medication for long lasting issues with brain fog or being unable to taste/smell, or enrolling in physical therapy to learn about exercises that can help with breathing or helping with cardiac endurance
Assume that you are working at a local health department that developing plans to decrease transmission of COVID-19. Your team wants to determine what actions the health department would take to work on each level of prevention in population health: primary, secondary, and tertiary. For each of the types of prevention: 1.) Define the general goal of that level of prevention and 2.) Identify and describe an intervention for COVID-19 that would be appropriate for that level of prevention. Limit your response to no more than 150 words for each level Provide an answer to the above for primary prevention:
1. The general role of primary is to prevent disease before it occurs. In relation to COVID-19, it would be trying to prevent individuals from contacting the virus. 2. An example of primary prevention for COVID 19 could be vaccinating individuals to reduce the risk of obtaining the disease or spreading the disease if the individual does obtain it.
Given the incidence rates that are reported in the Results section of the abstract above, calculate the measure of association that you choose. Please give your answer rounded to the 100th decimal place (example 9.91)
1.22 Risk Ratio = rate in those with exposure / rate in those without exposure = 60.42 per 10,000 person-years / 49.32 per 10,000 person-years = 1.22
An etiologic fraction or attributable risk % is the proportion of disease (CVD) in childhood cancer survivors that is attributable to high-dose radiation exposure, or the proportion that could be prevented if high dose radiation exposure was eliminated. A researcher is interested in the relationship between gender and colon cancer mortality and has presented you with Table 1 below. Calculate the rate ratio for mortality of colon cancer for males compared to females in the patients <65. Please round your answer to the nearest 100th decimal place (Example 9.91).
1.39 RR = 9.3/6.7 = 1.39
What is the relative rate (rate ratio) of mortality for adults who were overweight (BMI ≥ 25.0 but <30) for at least 10 years compared to those who never had a BMI ≥ 25? Please round your answer to the 10th decimal place.
1.4 Rate ratio = (𝑖𝑛𝑐𝑖𝑑𝑒𝑛𝑐𝑒 𝑑𝑒𝑛𝑠𝑖𝑡𝑦 𝑟𝑎𝑡𝑒 𝑖𝑛 𝑡ℎ𝑒 𝑒𝑥𝑝𝑜𝑠𝑒𝑑/𝑖𝑛𝑐𝑖𝑑𝑒𝑛𝑐𝑒 𝑑𝑒𝑛𝑠𝑖𝑡𝑦 𝑟𝑎𝑡𝑒 𝑖𝑛 𝑡ℎ𝑒 𝑢𝑛𝑒𝑥𝑝𝑜𝑠𝑒𝑑) = ((0.00028/(0.00020)) = 1.4
A rate ratio is a comparison of two rates. Here we are interested in males compared to females, so males will be on the numerator. An interpretation of the Rate Ratio is "Among colon cancer patients younger than 65, the rate of mortality is 1.99 times higher in males compared to females. Using Table 1 above, calculate the rate ratio for mortality of colon cancer for males compared to female in patients >65. Please round your answer to the nearest 100th decimal place.
1.49 RR = 80.1/53.9 = 1.49
What was the incidence density rate per 100 person-years for the employees exposed to the chemical spill in 2020? Provide your answer as a whole number with one decimal point per 100 person-years.
121 Person time = (50x1 month)+(30x2 months)+(20x3 months)+(1x2 months)+(1x5 months)+(68x1 year) = 82.75 person years IDR = 100/82.75 person years = 121 per 100 person years
Based on tables 5a and 5b above, what is the age-adjusted mortality rate for El Paso County in 2021 using Colorado as the standard population? (Please report your answer per 100,000 person-years rounded to the 10th decimal place.)
1266 Age-adjusted Mortality Rate for El Paso County = (50,851.91/4,016,676)* 100,000 = 1.266.0 per 100,000 person years
Based on tables 5a and 5b above, what is the age-adjusted mortality rate for Mesa County in 2021 using Colorado as the standard population? (Please report your answer per 100,000 person-years rounded to the 10th decimal place.)
1435.3 Age-adjusted Mortality Rate for Denver County =(57,651.51/4,016,676)* 100,000 = 1,435.3 per 100,000 person years
What is the cumulative incidence of psychosis (per 1,000) over the 4-year study period among individuals in this study who reported no cannabis use?
162 per 1000 342/2117 = 0.162 * 1,000 = 162 per 1,000
Poudre School District hires you to provide risk information about the flu in high school students from the previous school year (August 2021 - March 2022). In order to do this, you decide to calculate the cumulative incidence of flu. Records show 1,422 students were out sick from the flu at some point during the last school year. At the beginning of the year, in August 2021, there were 18,236 registered students. 234 students had moved away by the halfway point and an additional 126 students left by the end of the year. The district gained 43 new students during the year. To calculate the cumulative incidence (CI) or risk of flu among students at the school, which denominator should you use? Please enter a whole number representing the denominator for the calculation of CI. The denominator in cumulative incidence is those at risk at the beginning of the study or timeframe
18,236
What is the Mantel Haenszel adjusted odds ratio across age strata? Please round your answer rounded to the 100th decimal place.
2.01 [(147*84)/420]+[(130*125)/420]) / ([(63*126)/420]+[(60*105)/420]) = (29.4 + 38.7)/(18.9 + 15) = 2.01
A participant in the study requests the overall study results. You decide to first provide a crude measure of association. What number should be reported in the following sentence? The odds of reporting high stress is ________ times higher in people with severe acne, compared to those with no severe acne. Please round your answer rounded to the 100th decimal place (example: 9.49)
2.04 (277*209)/(123*231) = 2.04
What is the stratified OR for high stress and severe acne among those 20 or older? Please round your answer rounded to the 100th decimal place
2.58 OR = (130*125)/(60*105) = 2.58
Researchers in Spain conducted a study of the relationship between consumption of non-nutritive sweetened beverages and depression. They enrolled 3,000 young people aged 14 to 24 years drawn from the population registry offices of the city of Madrid and each of the 29 surrounding counties. Current intake of non-nutritive sweetened beverages and depression symptoms were ascertained at baseline and again at follow-up 4 years later. Depression was determined by interview with trained psychologists using the CES-D instrument. At follow-up, 792 individuals had reported at least one depressive symptom over the 4 year period and their frequency of non-nutritive sweetened beverage intake is provided in the table below. Assume that there was no loss to follow-up. . For individuals in this study described above, what is the cumulative incidence of depression (per 1,000) over the 4-year study period? Report your answer rounded to the 10th decimal place.
264 per 1000 792/3000 = 0.264* 1,000 =
An epidemiologist is interested in the rate of hypertension in a population of 300 nursing home residents who are known to be at risk for this condition. Blood pressures on all at-risk residents showed that 7 already had hypertension. The epidemiologist chose to follow the residents for a total of 1 year. 240 residents were followed for the entire 1-year period and among these residents there were 7 cases of hypertension. For various reasons, 53 residents could only be followed for 6 months; among these residents there were 2 cases of hypertension. What is the incidence density of hypertension per 1,000 person years? Please round your answer to the nearest whole number.
34 The 7 residents that had hypertension at the start must be excluded so the population size is 293. Next, calculate person-years for the denominator: (240*1year + 53*0.5year) The numerator is the number of new diabetes diagnoses over the follow-up period: 7 + 2= 9. Finally, calculate rate: [9 / (240 + 53*0.5)] * 1000 = 34 cases per 1,000 person-years
What is the number of expected esophageal cancer deaths for New Mexico in the 0-14 age strata if the U.S. age-specific rates apply? Please round your answer to the nearest integer (whole number).
41 Expected number of cases = (828,663 * 5)/ 100,000 = 41
An epidemiologist is interested in studying the rate of hospital admissions for alcohol use in a population of 3,000 college students known to be at risk. The epidemiologist chose to follow these students for a total of 4 years. A total of 1,475 students were followed for the entire 4-year period, and 250 alcohol-related hospital admissions were among these students. 725 students were followed for 3 years and among these students, there were 80 alcohol-related hospital admissions. 495 students were followed for 2 years and among these, there were 45 alcohol-related hospital admissions. 305 students were followed for only 6 months and among these students, there were 25 alcohol-related hospital admissions. What is the incidence density of alcohol-related hospital admissions per 1000 person-years from this study? Please round your answer to the 10th decimal place.
43.4 The total person time is (1475*4) + (725*3) + (495*2) + (305*0.5) = 9217.5 Your numerator is the number of students admitted for alcohol use over the 4-year follow-up period (250 + 80 + 45 + 25 = 400). Your rate calculation should look like this: IDR=400/9217.5=0.04339571467*(1000 person years) =43.3957 = 43.4 per 1000 person years
For every 100 new cases of Legionnaires' disease, 5 cases will die. Given this, what is the case fatality? Please select one answer
5%
You evaluate the relationship between aronobiotic among individuals with community-acquired pneumonia and rash risk. What is the risk of rash for individuals with community-acquired pneumonia who took aronobiotic compared to individuals with community-acquired pneumonia who did not take aronobiotic, given the study design? (Choose the best answer)
5.13 = (531/1503)/(801/11634)=5.13
What is the cumulative survival at the end of the 6th year among participants of this study (using the life table)? Please give your answer as a percentage (multiply by 100) rounded to the 10th decimal place. (i.e.: 14.1%)
51.4
On January 1, 2020 a tragic spill occurred at a chemical plant. On that day, 170 employees were exposed to the chemical spill, which is known to cause skin lesions. 50 employees develop lesions after 1 month, 30 after 2 months, and 20 more after 3 months, but all of them were still able to go to work. The remaining employees do not develop skin lesions. However, 2 employees die from other causes during the course of the year. One died on March 1, one on June 1. On July 31, five employees of the 170 employees exposed retired from their job, but agreed to remain available for follow-up. Fortunately, that year there were no additional developments of disease among those that retired or those that continued to work. Use the above information to answer the following 2 questions: What was the cumulative incidence of skin lesions, for the employees exposed to the chemical spill in 2020, per 100 people? Please provide a whole number with one decimal point.
59 CI = (50+30+20)/170 = 0.59 = 59 per 100
A study was conducted regarding cardiovascular diseases among 4,042 five-year survivors of a childhood cancer diagnosed before 1986 in France and the United Kingdom. Information on treatment was collected, and 2,520 patients were classified as having received "high dose" radiotherapy and 1,522 patients were classified as having received "low/no dose" radiotherapy. After an average follow-up of 27 years where no participants were lost to follow-up, 35 members of the cohort had died as a result of cardiovascular diseases. Calculate the most appropriate measure of the association of high dose radiation treatment for childhood cancer and cardiovascular diseases. (Choose the one best answer)
6.5
. A study was conducted regarding cardiovascular diseases among 6,843 five-year survivors of a childhood cancer diagnosed before 1986 in France and the United Kingdom. Information on radiation treatment was collected, and 2,870 patients were classified as having received "high dose" and 3,973 patients were classified as having received "low/no dose" radiotherapy. After an average follow-up of 29 years where no participants were lost to follow-up, 82 members of the cohort exposed to high dose radiation developed CVD. Also, 3,937 members who received low/no dose radiation did not develop CVD. What is the attributable risk percentage of CVD risk among childhood cancer survivors that is associated with high dose radiation treatment in this study? (choose the one best answer
68.3
A study was conducted regarding cardiovascular diseases (CVD) among 6,843 five-year survivors of a childhood cancer diagnosed before 1986 in France and the United Kingdom. Information on radiation treatment was collected, and 2,870 patients were classified as having received "high dose" and 3,973 patients were classified as having received "low/no dose" radiotherapy. After an average follow-up of 29 years where no participants were lost to follow-up, 82 members of the cohort exposed to high dose radiation developed CVD. Also, 3,937 members who received low/no dose radiation did not develop CVD. What is the attributable risk percent % of CVD risk among childhood cancer survivors that is associated with high dose radiation treatment in this study? (set up a 2x2 table to assist you in choosing the one best answer)
68.3% AR = (I(exp) - I (unexp))/I(exp) x 100% [(82/2870) - (36/3973)]/(82/2870) x 100% = 68.3%
What is the adjusted number at risk during the 3rd year interval of the study? Please round your answer to the 10th decimal place.
77.5 In the actuarial life table method, each individual who is censored (withdraws) contributes ½ of their person-time to that interval. So, the "Adjusted number at risk during the interval" equals the number alive at the beginning of the interval minus one-half of the number lost to follow-up. During year 3, 3 individuals were censored, thus we multiply 3*0.5 = 1.5. We then subtract 3 from 79 = 77.5
What is the attributable rate for adults who experience and overweight BMI for at least 10 years as compared to those who never had a BMI ≥ 25? (Choose the best answer).
8 per 100,000 person years Attributable risk is an estimate of the amount of disease incidence (or risk) that can be attributed to a certain exposure. We can calculate the attributable risk with the formula: Attributable risk = Incidence in the exposed - Incidence in the unexposed Attributable risk = 0.00028 - 0.00020 = 0.00008 *100,000 = 8 per 100,000 person-years.
What is the etiologic fraction (also known as the attributable risk %) of rash risk among those exposed to aronobiotic use? (Choose the best answer)
80.5 Attributable risk %=[(incidence in exposed-incidence in unexposed)/(incidence in exposed)]*100 =[((531/1503)-(801/11634))/(531/1503)]*100=80.5%
What is the etiologic fraction (also known as the attributable risk %) of CVD risk among childhood cancer survivors that is associated with high dose radiation treatment in this study? (Choose the one best answer)
84.6%
You want to calculate the expected number of deaths among children in Colorado aged 1 to 18 years who are suffering from pediatric cancers. You plan to use the 2020 U.S. cancer mortality rates among children of the same ages as your reference population. Assume that the age strata of the pediatric cancer population are: 1-4, 5-9, 10-14, 15-18. What information is necessary to perform this indirect standardization? (Choose the best answer).
A and B The population of children in each age strata (1-4, 5-9, 10-14, 15-18) in Colorado. Age specific mortality rates according to ages 1-4, 5-9, 10-14, 15-18 among the US population due to pediatric cancer.
Over the past 30 years, many technical advances have been made in prevention and treatment of coronary heart disease. You are wondering to what extent has mortality from coronary heart disease declined in the US since 1980, and which demographic subgroups have experienced the greatest changes in risk of dying of this disease. a.) Describe a strong data collection method for measuring the outcome indicated (e.g.; survey, sample, medical records, environmental monitoring, etc.); b.) Suggest an existing source of data that uses that method of data collection (e.g. US Census, NHANES, BRFSS, etc.); c.) Explain why you chose that source
A. a strong data collection method for measuring the outcome indicated above is by using medical records and monitoring environmental factors. Though medical practices have advanced there can be other factors that affect coronary heart like diet and exercise. Monitoring medical records and the environment can show this. For example if fast food is cheaper than healthier foods, more people are likely to buy fast food, and this can be confirmed by people's medical records if asked about diet by their physician. b. an existing sources that can be used for data collection is the National Health and Nutrition Examination. c. This source can be used to see if any environmental factors can affect someone's health, like diet, and see if it has any correlation to heart disease. For example, if someone eats food with high amounts of fat, and has a history of heart disease, this can be a link between the two, especially if multiple people also show this.
The image below provides relative risks of several respiratory health outcomes before, during, and after wildfire exposure. What can you conclude based on this image? (mark all that apply)
AFTER a wildfire event and exposure to ozone adjusted for PM2.5, acute respiratory infection is a significant risk Most exposures indicate a statistically significant risk. The risks are the greatest when the RR is less than one
A study was conducted to identify the association between the frequency of dental exams and heart disease. The study also looked into whether or not age influenced the association. The following ratios were calculated: Crude OR Age <65 Age >65 MH Adjusted OR 4.62 1.41 1.45 1.43 Which of the following would be reported to best describe the association between dental exams, heart disease, and age? Assume a 10% criteria to assess effect modification or confounding
Age is a confounder; report the MH Adjusted OR
You decide to use a case-control study design to assess risk factors for unintentional drug-related overdose mortality. Cases are defined as the 1,680 deaths due to unintentional drug-related overdose in 2021 in Colorado. What is/are the ESSENTIAL characteristic(s) that you must consider when selecting controls? (Choose the best answer).
B and D The controls cannot be individuals who experienced unintentional drug-related overdose mortality in 2021. The controls must draw from the same population that gave rise to the cases (Colorado).
With about 400,000 interviews being conducted annually, which of the following is one of the largest continuous telephone surveys in the world?
Behavioral Risk Factor Surveillance System
An investigator is evaluating the effect of tea tree oil on the eradication of toenail fungus in a randomized controlled trial. The outcome of toenail fungus will be ascertained by clinician examination. However, the investigator is concerned that clinicians may more favorably rate improvement for participants they know had the tea tree oil treatment (information bias). Which design-level strategy could the investigator use to decrease this type of information bias? (Choose the best answer)
Blinding of study personnel (including examining clinicians to treatment assignment).
Based on the data provided (above), which of the following options best describes the relationship of gender to the association between Treatment A and Disease X? Assume 10% is the criteria for meaningful effect modification or confounding. (Choose the best answer)
Gender is an effect modifier so we would report the stratum-specific risk ratios.
How would you interpret the attributable risk percent determined above? (choose the one best answer)
It is the proportion of CVD among childhood cancer survivors that is a result of high dose radiation treatment
How would you interpret the etiologic fraction from Question 18? (Choose the one best answer) ___ It is the difference in the incidence of CVD in the population among those exposed and not exposed to high-dose radiation treatment. ___ It is the proportion of cancer attributable to not being exposed to high dose radiation treatment. ___ It is the ratio of CVD incidence in the exposed versus the unexposed. ___ It the absolute risk due to exposure in the population. ___ It is the proportion of CVD among childhood cancer survivors that is a result of high dose radiation treatment
It is the proportion of CVD among childhood cancer survivors that is a result of high dose radiation treatment
How would you interpret the etiologic fraction from Question 16? (Choose the best answer)
It is the proportion of rash incidence among exposed adults with community-acquired pneumonia attributed to aronobiotic use.
What is one of the advantages of conducting a case-control study over a cohort study for unintentional drug-related overdose mortality? (Choose the best answer).
It would be quicker and cheaper than a cohort study.
Quote from a news report: "Based on interviews and blood samples of over 8,000 persons, 11% of persons classified as heavy drinkers of alcohol were involved in home injuries over a three-month period." Can we conclude that there is an association between drinking and home injuries from these data? Please respond YES or NO and provide a 1-2 sentence justification for your answer.
No, there are a lot of other factors to consider when it comes to home injuries. Are home injuries including getting hurt at that individual who got hurt at home or did they get hurt in someone else's house? It also depends on what they are considering as heavy drinkers, for example, are they counting how many drinks those persons had, or are they using blood alcohol levels to determine if that person is a heavy drinker or not? To determine an association, we must have a comparison group
A study sought to understand the association of smoking with lung cancer. The investigators recruited 530 patients with lung cancer and 550 subjects without lung cancer from the University of Colorado Hospital. During the interviews, all subjects answered questions related to their smoking status and other demographic details. After the conclusion of the study, the researchers found that "patients suffering from lung cancer are 57% more likely to have a history of smoking when compared to those without lung cancer". Based on these results, what measure of association does the statement relate to? (Choose the best answer).
Odds Ratio
Of the 365 subjects who report memory loss, 300 have active prescriptions for sleep medication. Of the 655 who do not report memory loss, 440 have active prescriptions for sleep medication. Calculate the appropriate measure of association and interpretation. (Please select only one. No partial credit)
Odds Ratio= 2.3. Interpretation: Individuals with memory loss are 2.3 times more likely to report sleep medication use than individuals without memory loss.
Consider a study that aims to examine the association of wildfire smoke and asthma. Provide two possible confounders that could be concern when conducting this study. Briefly explain why these factors could be considered confounders
One confounder for this study could be work places. If someone works remotely they are not exposed to the outdoors as often as people who commute to work on a daily basis. Those who work remotely might not even leave their house in general as those who commute to work. A second confounder could be the exercise location. People who exercise outside breathe in more 'fresh' air than those who exercise at the gym. If a wildfire occurs and they choose to walk or run outside, they breathe in more of that air than someone who exercises in their home or at the gym. Another aspect of determining a confounder: it cannot be on the causal chain of risk
Which of the following would be accurate conclusions about the mortality rates in El Paso and Mesa counties based on your answers to Questions 21 and 22 and the data in tables 5a and 5b? (Choose the best answer).
Options A, C and D The age-adjusted mortality rate among adults ≥ 25 in Mesa County is higher than that of El Paso County in 2021. The age-specific mortality rate of each age group (25-44, 45-64, ≥65) is higher in Mesa County than in El Paso County in 2021. There is a higher proportion of "young adults" aged 25-44 in El Paso adult population compared to Mesa.
Given the value that you calculated above, how would you interpret the relationship between infection with GAS and neuropsychiatric disorders?
People with a history of GAS infection have a 22.5% higher risk of developing neuropsychiatric disorders.
The difference between point prevalence and period prevalence is: (choose one best answer)
Point prevalence accounts for all existing cases at a point in time while period prevalence accounts for all existing cases over a specified period of time.
Adults (30-75 years) were recruited and classified as: (1) tobacco smokers, if they smoked ≥1 tobacco cigarette/day, (2) e-cigarette users, if they inhaled ≥50 puffs/week of any type of e-cigarette and (3) dual users, if they smoked tobacco cigarettes and also used e-cigarettes. Follow-up at 24 months were available for 229 e-cigarette users, 480 tobacco smokers and 223 dual users (overall, follow up was complete on 68.8% of participants). Self-rated health and adverse events were similar between all groups. Those who continued dual using or converted from tobacco smoking to dual use during followup experienced significant improvements in the 3 main outcomes of interest, compared with those who continued or switched to only smoking tobacco (p<0.001). What study design best describes this description? (Choose the one best answer)
Prospective cohort
It's March of 2023, you're an epidemiologist working at Foundation Hospital, a small local hospital. You are interested in the relationship between vaccination against COVID-19 and mechanical ventilation (also called intubation). Vaccination status is your exposure and mechanical ventilation is your outcome. You define your study population as all adult patients who were hospitalized at your facility with a COVID-19 infection in 2022 (n=880). Patient vaccination status is recorded in the medical record at the time the vaccine is given. Using the medical record system, you find out whether or not each individual received mechanical ventilation during their COVID-19 hospitalization. Of the 880 individuals hospitalized with COVID-19 in 2022 at your facility, a total of 540 had completed a primary COVID-19 vaccine prior to their hospitalization. 78 vaccinated individuals required mechanical ventilation. Of the total 340 individuals who were not vaccinated, 79 required mechanical ventilation. What type of study design is this?
Retrospective Cohort
A case-control study was conducted to assess the association between high stress levels and severe acne. Participants included 400 people with severe acne and 440 without severe acne. When stratified by age, the following counts in each category were observed: What is the best measure of association to use to examine the exposure-disease relationship?
Risk ratio
Based on the article we read, "Outbreaks of Hepatitis A in US Communities, 2017-2018: Firsthand Experiences and Operational Lessons From Public Health Responses" by Snyder et. al, what were some of the challenges associated with managing the Hepatitis A epidemic that began in 2017? Mark all that apply
Sanitation and hygiene infrastructure Lack of vaccination in exposed populations Public health workforce limitations Stigma associated with the disease Communication challenges among different municipalities and agencies
A study was conducted on the risk of shingles among people over the age of 50 in relation to their recent shingles vaccination history. Over a one-year follow-up period, there were 943 shingles cases among 77,738 vaccinated subjects and 1,361 shingles cases among 62,217 unvaccinated subjects. Set up a 2x2 table and consider the vaccine to be the exposure of interest. Then, calculate the risk difference (RD) and the risk ratio (RR). Based on these data and your calculated results, mark all statements that are true
Subjects with recent shingles vaccinations had 98 fewer shingles cases per 10,000 subjects over the year compared to subjects without a recent shingles vaccination. Subjects with recent shingles vaccinations had 98 fewer shingles cases per 10,000 subjects over the year compared to subjects without a recent shingles vaccination. Subjects with recent shingles vaccinations had a 45% reduced risk of shingles over the following year as compared to subjects without recent shingles vaccinations.
Each type of study design has advantages and disadvantages. All of the statements below are general advantages of cohort studies, EXCEPT? ___ Allow for calculation of incidence ___ They maintain the temporal relationship between exposure and disease ___ The design is efficient for assessing rare diseases/outcomes ___ The design is efficient for assessing multiple diseases/outcomes ___ Recall bias is less of a problem in prospective cohort studies
The design is efficient for assessing rare diseases/outcomes
What are the possible threats to external validity in this study? ___The individuals in the study are not comparable to other populations with similar cannabis use ___ Low reliability of the instrument to assess psychosis ___ Residual confounding ___ Interviewer bias ___ None of the above
The individuals in the study are not comparable to other populations with similar cannabis use
In a county that does not require measles vaccination, a preschool experienced a prolonged measles outbreak among its student beginning in September 2016 through December 2016. To calculate the cumulative incidence or risk of measles among students at the preschool, which denominator should you use?
The number of susceptible students at the beginning of the period (September 2016)
What is the difference between period prevalence and point prevalence? (Choose the best answer) The period prevalence denominator is the total person time contributed while the point prevalence denominator is the number of people at risk at a given time. You Answered Period prevalence is used to determine the burden of disease at a specific time point, while point prevalence measures the burden of disease during the study interval. Correct Answer The point prevalence denominator is the population at a specific time point while the period prevalence denominator is the average population over the period. Period prevalence is a proportion while point prevalence is a rate. There is no difference
The point prevalence denominator is the population at a specific time point while the period prevalence denominator is the average population over the period.
Using the study data presented above, which of the following is the correct interpretation of the risk of mechanical ventilation comparing vaccinated to unvaccinated patients at Foundation Hospital? (Choose the best answer)
The risk of mechanical ventilation is 38% lower among vaccinated compared to unvaccinated patients admitted to Foundation Hospital. RR = (78/540)/(79/340) = 0.62 The risk of mechanical ventilation comparing vaccinated to unvaccinated is 0.62, or 38% lower among those "exposed" to the vaccine compared to those "unexposed" to the vaccine.
In a cohort study, investigators determined that the RR was 9.327 with a confidence interval of 2.05 to 42.22. What can you conclude from these numbers?
The risk was increased due to exposure and statistically significant
The following are results of a randomized clinical trial of New Therapy A and Usual Therapy B to reduce new events. Which of the following statements is most correct about the trial? Assume everyone completed the study after receiving the correct treatment for 6 months. (Choose the one best answer)
Therapy A is better than B since the RR of A/B is 0.73
Randomization is a procedure used for the assignment or allocation of subjects to treatment and control groups in experimental studies. Randomization increases the likelihood that: (Choose the best answer)
Treatment and control groups are similar except for the presence of treatment.
You cannot simply count events by therapy, since the number of subjects in each group differs. You must calculate the cumulative incidence as 'new events' / 'participants' (in this example). So the cumulative incidence in A = 456/1289 = 0.354 (or 35.4%); and in B = 890/2030 = 0.485 (or 48.5%). The RR of A/B = (0.354 / 0.485) = 0.73. Because the RR is less than 1, this indicates that the number of new events in group A were less than group B. In a study on diet and cardiovascular disease (CVD), investigators prospectively follow a group of 200 vegetarians and 400 omnivores. They were interested in the effect of a vegetarian diet on risk of CVD. After 20 years of follow-up, 15 of the vegetarians and 40 of the omnivores develop cardiovascular disease (CVD). The 95% confidence interval on the relative risk of 0.75 ranges from 0.5 to 0.9. Which of the following statements is correct?
Vegetarians were 25% less likely to develop CVD during 20 years of follow-up compared with omnivores
Despite some experiencing economic prosperity in the US, the burden of poverty has not decreased. In the absence of economic resources, communities struggle to meet their basic needs. You would like to understand food insecurity - how common it is and how its prevalence may vary by age, geography, income, and employment status. a.) Describe a strong data collection method for measuring the outcome indicated (e.g.; survey, sample, medical records, environmental monitoring, etc.); b.) Suggest an existing source of data that uses that method of data collection (e.g. US Census, NHANES, BRFSS, etc.); c.) Explain why you chose that source.
a. For this situation I would use surveys. A lot of people who are in the minority population might not have access to healthcare or other necessary services, so the best way to ask this certain population about what they need or want more information on is best by simply asking them in a survey b. The best existing source to use is the National Health and Nutrition Examination Survey (NHANES) c. because this survey included home and mobile interviews, this would be the best way to get information about food insecurity, especially in communities where people may not have a home
Relatively short intervals between pregnancies have been associated with increased risk of adverse birth outcomes. Health education and better access to family-planning services have been proposed as preventive strategies. To help guide resources toward women at highest risk, you would like to know if the frequency of short interpregnancy intervals vary in relation to maternal age, education and marital status? a.) Describe a strong data collection method for measuring the outcome indicated (e.g.; survey, sample, medical records, environmental monitoring, etc.); b.) Suggest an existing source of data that uses that method of data collection (e.g. US Census, NHANES, BRFSS, etc.); c.) Explain why you chose that source.
a. I believe that the best way to find information about maternal age, education, and marital status is by gathering surveys or medical records. If the pregnancy already happened, there theoretically should be medical records about it, and most of the time when you go to the doctor they ask about all these factors. I could also ask surveys to women and see if they received any prior education. b. An existing source I could use is the US Census or the National Vital Statistics System. c. Both of these sources list information about births however the vital Statistics also list birth records like birth weight, pediatric conditions and other info. The census includes information about education, income, health insurance, and other additional characteristics that may be useful
Clinical liver-disease specialists have the impression that they are seeing more and more patients with hepatocelluar carcinoma. You would like to investigate if the incidence of this malignancy actually risen in the past two decades. a.) Describe a strong data collection method for measuring the outcome indicated (e.g.; survey, sample, medical records, environmental monitoring, etc.); b.) Suggest an existing source of data that uses that method of data collection (e.g. US Census, NHANES, BRFSS, etc.); c.) Explain why you chose that source.
a. for this condition I would check in with registries. If this condition is linked to cancer, it should be listed in a registry, and can be monitored across the country. If not you could review medical records and see if there is a similar pattern in other patients. b. A good existing source would be the Surveillance, Epidemiology, and End Results Program (SEER). c. This is the National cancer survey and can show a rise or fall in this current illness if there is one. You can also look up previous years if you want to find data beyond 2 decades
Select the study finding that most appropriately matches the specific concept of life course modeling for health Exposure to thalidomide during gestation increases risk of limb abnormalities
accumulation of risks
The Depression Clinic at the University of Colorado wants to study the association between memory loss and sleep medication use. They recruited 365 individuals from their clinic who report memory loss and 655 individuals who are seeking treatment for other issues but have not reported memory problems. The researchers then abstracted the medical records to ascertain past prescriptions for sleep medication. What type of study design is this?
case control
Select the study finding that most appropriately matches the specific concept of life course modeling for health An underlying genetic factor causes poor health which, in turn, leads to low socioeconomic status, which in turn, leads to worsening health
chain of risk/trigger effect
Based on the study in question 3, the researchers wanted to determine if age affected the association between sleep medication use and memory loss. They stratified the subjects according to age < 60 years and age > 60 years. Based on this data, what role does age play in this study?
confounder
Select the study finding that most appropriately matches the specific concept of life course modeling for health Interviews with 150 Palestinian mothers and their children living amidst the intifada in the West Bank determined that the number of risks present in a child's life was correlated to behavioral problems
critical period
Select the appropriate interpretation for each effect measure 7,464 women were randomly assigned to 400 IU of vitamin E or placebo and followed for 5 years to monitor for the primary outcome of stroke. A total of 772 women out of the 3,727 randomized to vitamin E supplements had a primary outcome of stoke
cumulative incidence
Based on the data provided, which of Hill's criteria for assessing causality is demonstrated by this study? (select one best response, HINT: Use no cannabis use as your reference group)
dose response
Selection bias is more of a problem in cohort studies than in case-control studies (true/false)?
false
What are the possible threats to internal validity in this study? (Select all that apply)
information bias misclassification of outcome misclassification of exposure
Which of the following are appropriate methods to control for confounding? (Select all that apply) increased sample size matching randomization stratification covariate adjustment
matching randomization covariate adjustment
Select the appropriate interpretation for each effect measure 24.7 per 100,000 children aged 6-9 died of unintentional injury in 2007 in Colorado
mortality rate
Randomization and double-blinding in a controlled trial are intended to accomplish all of the following EXCEPT: Minimize Bias Optimize External Validity Reduce or Eliminate Known Confounders Reduce or Eliminate Unknown Confounders Produce Similar Groups that Differ by the Intervention Only
optimize external validity
Select the appropriate interpretation for each effect measure 15.1% of childhood learning delays in Colorado are due to lead exposure
population attributable risk
Which of the following measures of impact reflects the proportion of risk or rates in the population that is attributed to the exposure?
population attributable risk percentage
The introduction of anti-retroviral therapy has improved survival in individuals with HIV. Notably, this therapy has not cured HIV positive individuals. If all other factors were held constant, how would the introduction of this therapy change a measure of disease occurrence? (Choose the best answer)
prevalence will increase
Researchers in Germany conducted a study of the relationship between cannabis use and psychosis. They enrolled 2,457 young people aged 14 to 24 years drawn from the population registry offices of the city of Munich and each of the 29 surrounding counties. History of cannabis use and psychosis was ascertained at baseline and again at follow-up 4 years later. Psychosis was determined by interview with trained psychologists using the M-CIDI instrument. Individuals with psychosis at baseline were excluded. At follow-up 431 individuals had reported at least one psychotic symptom over the 4 year period and their frequency of cannabis use is provided in the table below what is the study design?
prospective cohort
Select the appropriate interpretation for each effect measure The mortality rate from motor vehicle accidents was 4.5 times greater among Hispanic youth than non-Hispanic white youth aged 15-19 in 2012
rate ratio
Calculate the appropriate measure of association for the relationship between cannabis use ≥ 5 times per week and any report of psychotic symptoms at follow up using the reference group of no cannabis use?
relative risk = 2.7
Results from an epidemiological study were published in an article titled "Green Tea Consumption and Mortality among Japanese Elderly People: The Prospective Shizouka Elderly Cohort." The following information comes from the published article: BACKGROUND: Green tea has been extensively studied for its potential preventive role, especially for cardiovascular disease and cancer. Data from animal studies support this role, but the results of prior epidemiological studies have been inconsistent, and so the effects of green tea remain unclear in humans. PURPOSE: To investigate the association between green tea consumption and mortality from all causes, cancer, and cardiovascular disease among elderly people. METHODS: A total of 22,200 elderly residents (aged 65-84 years) were randomly chosen from all 74 municipalities in the Shizuoka prefecture in Japan. The Shizuoka prefecture has a population of 3.8 million people among 1.3 million households. A total of 14,001 of the randomly selected residents agreed to participate in the study and returned the study questionnaire, in December 1999. The questionnaire included an item on current green tea consumption. Participants were followed for up to 6 years from submission of their questionnaire to December 2005 to determine who died and their causes of death. These data were analyzed to determine levels of green tea consumption among participants (which ranged from less than 1 cup/day to more than 7 cups/day) and the relationship between green tea consumption and mortality from all causes, cancer, and cardiovascular disease.
retrospective cohort
