epidemiology תשפא מועד א

A researcher followed 60,000 workers in the metal manufacturing industry over a period of 5 years. 20,000 of the workers were exposed to harmful substances. The other 40,000 workers were not exposed to harmful substances. At the end of the period, it was found that 1,000 of the exposed workers and 1,000 of the non-exposed workers developed a respiratory disease. Which of the following best describes the study's findings?

RR (Rate Ratio) = 2.0. Therefore, exposure is a risk factor.

Which of the following is an advantage of a cross-sectional study design compared to an ecological study design?

In a cross-sectional study design, there is data about the individual, which prevents ecological fallacy.

Imposing a lockdown on the population during an epidemic constitutes:

Primary prevention designed to reduce the incidence of the disease, which will subsequently lead to a reduction in the prevalence of the disease.

It is known that the sensitivity of a test is 80% and the specificity of the test is 75%. What percentage of the sick patients received a negative test result?

False negative = 20%

What does the following statement describe: "This year, 50 new cases of hepatitis were recorded in the population"?

None of the answers

In a country with an average population of 2,000,000 people, 1,050 births occurred during the year, out of which 50 were stillbirths. 1,000 people died during the year. Additionally, the country absorbed 400 new immigrants (Olim) during the year and 600 people emigrated (Yordim) from it. What is the natural increase in this population in this year?

0

What can be determined based on these data regarding the survival rate from cancer during the year 2020? (Data: City A Pop=200k, Prev=1k, Inc=300, Deaths=200 | City B Pop=400k, Prev=2k, Inc=900, Deaths=150)

The survival rate from the disease is higher in City B compared to City A.

Which of the following situations is most closely linked to herd immunity?

An increase in the level of immunity of both the vaccinated and non-vaccinated.

Given: In Country Banana, incidence rates for ischemic heart disease are low compared to Country Apple. In Country Banana, prevalence rates for ischemic heart disease are high compared to Country Apple. Which of the following could explain this phenomenon?

In Country Banana, mortality rates from the disease are lower compared to Country Apple.

In which of the following cases would you NOT recommend performing a test for early diagnosis (screening) of a disease?

A disease with a short pre-clinical phase.

A certain disease has a screening test/evaluation with high specificity and low sensitivity. What is true about the test?

It has a low false positive rate and a high false negative rate.

Setting up COVID-19 testing stations in commercial centers constitutes:

Secondary prevention activity—which may increase recorded disease incidence rates.

The Ministry of Health released a statement: "Usually there are 4-5 new cases in the city's population per week, but last week there were 400 cases. This impressive increase in the disease incidence, according to World Health Organization data, was recorded in all countries of the world." What type of event is this?

Pandemic

In which of the following study designs is it impossible to measure incidence and/or prevalence rates of a disease?

Case-control study

The threshold value for determining a normal cholesterol level was raised from 100 to 150. What might this lead to?

A decrease in sensitivity and an increase in specificity of the test.

It was found that the life expectancy at birth for men in the year 2020 in a certain country in Africa is 65. It is known that infant mortality in this country is relatively high. According to these data, what is the life expectancy at age 10 in the population in this year?

More than 55 years of life

In order to test the association between smoking and the risk of developing lung cancer, a researcher selected 500 patients with lung cancer and matched them with 1,100 controls. He asked all participants about their smoking habits. 200 of the patients and 200 of the controls had smoked at least 4 cigarettes on average every day during their lifetime. Based on this study, can it be argued that smoking constitutes a causal factor for the development of lung cancer?

No, in this study design it is impossible to guarantee the condition of temporality (time order) to establish a causal relationship.

In order to test the association between smoking and the risk of developing lung cancer, a researcher selected 500 patients with lung cancer and matched them with 1,100 controls. He asked all participants about their smoking habits. 200 of the patients and 200 of the controls had smoked at least 4 cigarettes on average every day during their lifetime. What can be learned from the study results?

OR = 3.0. According to the results of this study, smoking constitutes a risk factor.

Which of the following types of incidence is expected after the successful completion of a disease eradication process?

There will be no new cases of morbidity and the disease incidence rate will be zero.

Given: In a city with an average population of 1,000,000, 1,050 births occurred during the year, 50 of which were stillbirths. Infant death data: 100 died in 1st year (40 in 1st week, 20 in weeks 2-4). What is the post-neonatal mortality rate in the population during the year?

40/1,000

Given: In a city with an average population of 1,000,000, 1,050 births occurred during the year, 50 of which were stillbirths. Infant death data: 100 died in 1st year (40 in 1st week, 20 in weeks 2-4). What is the perinatal mortality rate in the population during the year?

90/1,000 or 85.71/1,000

On 1.1.1950, 50 cases of tuberculosis were registered in the District Health Office. During the year, 20 patients died, and 15 new cases were detected. Average pop = 10,000. What was the annual incidence rate for tuberculosis in 1950?

15/10,000

What can be determined based on these data regarding the point prevalence rate of cancer in the population at the beginning of the year? (Data: City A Pop=200k, Prev=1k, Inc=300, Deaths=200 | City B Pop=400k, Prev=2k, Inc=900, Deaths=150)

The point prevalence rate is similar in both cities.

What can be determined based on these data regarding the incidence rate of cancer during the year 2020? (Data: City A Pop=200k, Prev=1k, Inc=300, Deaths=200 | City B Pop=400k, Prev=2k, Inc=900, Deaths=150)

The incidence rate of the disease is higher in City B compared to City A.

A researcher followed a city's population for 5 years to examine the association between living near the coast and skin cancer. 12 out of 10,000 coastal residents vs 24 out of 20,000 non-coastal residents developed skin cancer. Which best fits the results?

According to the results of this study, no association was found between living near the coast and skin cancer morbidity.

A researcher wanted to test the association between meat consumption and colon cancer morbidity. He recruited 100 patients with colon cancer and 200 healthy controls, then collected data from the past regarding meat consumption. Which best describes this type of study?

This is a case-control study, retrospective.

Which of the following study designs is best suited for identifying risk factors and protective factors for a very rare disease?

Case-control study design

What can be determined based on these data regarding the proportional mortality ratio/rate for cancer during the year 2020? (Updated Data: City A Deaths=200/600 Total | City B Deaths=160/480 Total)

The proportional mortality rate for the disease in both cities is similar and stands at 33.3%.

What can be determined based on these data regarding the prevalence rate of cancer during the year 2020? (Updated Data: City A Deaths=200/600 Total | City B Deaths=160/480 Total)

The prevalence rate of cancer during the year is higher in City B compared to City A.

In a country with an average population of 6,500,000 people, out of which 500,000 are women of childbearing age, 1,100 births occurred during the year, including 100 stillbirths. What is the general fertility rate in the population in this year?

Cannot be calculated based on the data.

How would a fetus weighing 1,000 grams at week 22 be defined if it showed no signs of life upon separation from its mother's womb?

Stillbirth

In a country with an average population of 2,000,000 people, out of which 400,000 are women of childbearing age, 1,050 births occurred during the year, including 50 stillbirths. 1,000 people died, and 400 new immigrants arrived. What is the crude birth rate in the population in this year?

250/100,000