epidemiology exam תשפד

Question 1: Which of the following best describes the following scenario: In the past month, 150 new cases of disease X were discovered in this area, following decades during which no morbidity of the disease was recorded in the region?

Epidemic

Question 2: In the results of a cross-sectional study, it was found that performing physical activity constitutes a protective factor against the development of heart disease. Which of the following most correctly describes the study results?

The sick/healthy ratio among the exposed is lower than the sick/healthy ratio among the unexposed.

Question 3: In which of the following study designs is it possible to determine a causal relationship in an epidemiological study?

In an experimental research design or in a prospective cohort study.

Question 4: A novel screening test was found to have a Positive Predictive Value (PPV) level of 60% and a Negative Predictive Value (NPV) level of 40%. What does this mean?

A positive test result has a higher predictive capability than a negative result.

Question 5: In a study examining the relationship between smoking and lung cancer, the researcher selected on 1.1.2023 one hundred and fifty lung cancer patients living in City A and one hundred and fifty healthy people living in the same city. Past smoking habits were examined in all subjects and compared between the two groups. Which of the following most correctly describes this study?

Case-control study; Outcome variable - lung cancer.

Question 6: Which of the following changes is likely to occur as a result of implementing a program that encourages women aged 50 and over to undergo a mammography test?

An increase in registered incidence of breast cancer among women aged 50 and over. A decrease in case-fatality rates from breast cancer among sick women aged 50 and over. An increase in the prevalence rate of the disease in its early stages among women aged 50 and over.

Question 7: In which of the following cases is it recommended to perform a test for early detection of a disease (screening tests)?

A disease with a long pre-clinical stage (latency time).

Question 8: How can providing chemotherapy treatment for women with metastatic breast cancer be described?

This is not a prevention program.

Question 9: On which of the following rates can the following claim be based: "This disease constitutes the third leading cause of death in the population this year"?

Proportional mortality rate.

Question 10: A researcher followed 200 patients who suffered a stroke. Approximately one year after the stroke diagnosis, the following results were observed: 30 of them died from the disease during the year, 110 were completely rehabilitated, and 60 remained disabled. What is the proportional mortality rate for stroke based on these data?

Based on these data, a proportional mortality rate cannot be calculated.

Question 11: The following validity metrics were measured for a screening test: Sensitivity level – 85%, Specificity level – 75%, Positive predictive value – 80%, Negative predictive value – 70%. Mr. Cohen received a negative result, what is the probability that he is healthy?

70%

Question 12: In the year 2018, the population of the city averaged 100,000 people. At the beginning of the year: 1,000 of them were sick with cancer and 2,000 of them were sick with ischemic heart disease. During the year, 200 of the cancer patients and 400 of the ischemic heart disease patients died. What can be learned from this information?

The survival rate from ischemic heart disease is identical to the survival rate from cancer.

Question 13: In a population numbering 1,000,000, 1,000 people died during the year: 400 died from ischemic heart disease, 300 died from cancer, 150 died from infectious diseases, and 100 died from external causes of death. Which of the following sentences is correct?

Question 14: The following information is given regarding the city's population in the year 1996: Average population size during the year: 30,000,000 residents; Total live births - 904,380; Stillbirths - 4,380; Death in the first week of life - 7,500; Death in the second, third, and fourth week of life - 3,000; Death from the beginning of the second month until one year of age - 4,900. What is the neonatal mortality rate?

(7,500+3,000) / 900,000

Question 15: In order to test the relationship between a Mediterranean diet and heart disease morbidity, 6,000 patients with heart disease and 12,000 controls who do not have heart disease were recruited for a study. The subjects were asked about their dietary habits over the past two years. The study found that 1,500 of the heart disease patients compared to 6,000 of the controls consume a Mediterranean diet. What can be learned from the study results?

OR=0.33, a Mediterranean diet constitutes a protective factor against heart disease.

Question 16: When planning a case-control study examining the relationship between exposure and morbidity, one must pay attention to the fact that:

The control group is similar to the study group in most characteristics except for the disease.

Question 17: Which of the following constitutes an advantage in a cohort study?

It allows for the calculation of incidence rates for the disease.

Question 18: Gaucher – is a genetic disease characterized by a deficiency of an enzyme that breaks down fats in the cell. This disease is relatively rare, and currently, 210 Gaucher patients live in Israel. Which of the following study designs is suitable for investigating the risk factors of this disease?

Case-control study.

Question 19: Which of the following will lead to an increase in the prevalence of a disease and will not lead to a change in the incidence of a non-communicable disease?

A decrease in the case-fatality of the disease. Negative migration of a healthy population moving to another city. Positive migration of a sick population moving to live in the city.

Question 20: The attached table describes the distribution of fecal occult blood test results for the early detection of colorectal cancer and the actual subsequent presence of the disease: Positive answer: 600 Sick, 400 Healthy. Negative answer: 400 Sick, 1,600 Healthy. Mr. Cohen received a negative result. What is the probability that he is nevertheless sick?

20%

Question 21: In a population numbering 100,000 on average, 1,000 people died during the year and 1,500 live births were born. What can be learned from this information?

Natural increase rate in the population in this year = 500/100,000.

Question 22: The Period Prevalence Rate of the Coronavirus disease among young adults aged 20-40 in the month of September 2021 expresses:

The number of Coronavirus patients among young adults aged 20-40 in the month of October 2020 in the population divided by the total number of young adults aged 20-40 in the population. (Note: The Hebrew text shifts between September and October in the wording).

Question 23: What does the claim describe: "On the date 1.9.2021, there were 58 sick people for every 100 healthy people in the city of Banana"?

Question 24: During the year, 10,000 live births and 400 stillbirths were born. During the first week from birth, 30 infants died. During weeks 2-4 from birth, another 20 infants died, and during months 2-12 from birth, another 15 infants died. What is the Neonatal mortality rate in the population in this year?

430/10,000

Question 25: At the beginning of the year 2022, 100,000 residents lived in the city, 1,000 of whom were diabetic. During the year, another 200 residents were diagnosed with diabetes. Assuming that during the year there were no deaths among diabetic patients, no cure for diabetes, no positive or negative migration of healthy or sick people in the city, and no changes in population size, what does the value 1,200/100,000 express?

Point prevalence rate of the disease on 31.12.2022 and period prevalence rate of the disease during the year.

Question 26: Which of the following rates will decrease following the discovery of an innovative treatment that prevents stillbirth?

Pre-natal mortality.

Question 27: To which of the following will the discovery of an innovative drug lead, which prevents death but does not cure a very common disease that constitutes one of the frequent causes of death in the population?

An increase in the prevalence rate of the disease. A decrease in the case-fatality rate of the disease. A decrease in the proportional mortality rate for the disease.

Question 28: The prevalence rate of a certain disease is five times higher in the population of City A compared to the population of City B. However, the incidence rates of the disease are identical in both cities. What could be the explanation for this?

Sick patients from City B tend to migrate to City A. The mortality rate from the disease in City B is higher. The cure rate of the disease in City B is higher.

Question 29: The threshold value of a certain test increased over the years from 100 to 150. In the past, values of 100 and above were defined as disease, and currently, values of 150 and above are defined as a state of disease. What will this change lead to?

A decrease in sensitivity and an increase in specificity.

Question 30: In a country numbering 6,500,000 people on average, out of which 500,000 are women of childbearing age, there were 1,100 births during the year, including 100 stillbirths. What is the crude fertility rate (or total fertility calculation based on the provided parameters) in the population in this year?

Cannot be calculated based on the data.

Question 31: Which of the following best fits a fetus weighing 400 grams at week 20 that showed no signs of life upon separation from its mother's womb?

Miscarriage (Abortion).

Question 32: The following are the birth and death data in the year 2022 in countries A and B: Country A: Avg Population 10M, Live Births 10k, Stillbirths 1,500, Deaths 20k. Country B: Avg Population 10M, Live Births 10k, Stillbirths 2,000, Deaths 20k. Which of the following claims is correct?

In both countries, a negative natural increase and a negative natural increase rate were recorded. The difference in the number of stillbirths between the countries will not affect the gap between them regarding natural increase or natural increase rate (Note: because natural increase only calculates live births minus deaths).

Question 33: The following are life expectancy data at birth in the country of Apple: In 1962 life expectancy at birth among men was 65; in 2022 it was 88. According to these data, how many years of life on average were expected in the year 1962 for a person born in that year in the country of Apple?

65 years of life.