HLPR 222 Questions

The population of a city on February 15, 2005, was 36,600. The city has a passive surveillance system that collects hospital and private physician reports of influenza cases every month. During the period between January 1 and April 1, 2005, 2,200 new cases of influenza occurred in the city. Of these cases, 775 persons were ill with influenza according to surveillance reports on April 1, 2005. The prevalence rate of active influenza as of April 1, 2005, was: 10 per 1,000 population 14 per 1,000 population 17.5 per 1,000 population 20 per 1,000 population

20 per 1,000 population

Which of the following statements are true? More than one answer may be correct. A mortality rate is an example of an incidence rate Death certificate data are generally valid regardless of the cause of death Type of disease is the most important predictor of mortality Changing diagnostic criteria does not affect estimates of prevalence and incidence

A mortality rate is an example of an incidence rate

which of the following improves the reliability of diabetes screening tests? Having the same lab analyze all samples Taking more than one sample for each subject and averaging the results Insuring that the instrument is standardized before each sample is analyzed a and c only All of the above

All of the above

Chicken pox is a highly communicable disease. It may be transmitted by direct contact with a person infected with the varicella-zoster virus (VZV). The typical incubation time is between 10 to 20 days. A boy started school 2 weeks after showing symptoms of chicken pox including mild fever, skin rash, and fluid-filled blisters. One month after the boy returned to school, none of his classmates had been infected by VZV. The main reason was: Herd immunity All had been immunized prior to the school year Contact was after infectious period Subclinical infections were not yet detected Disease was endemic in the class

Contact was after infectious period

The ability of a single person to remain free of clinical illness following exposure to an infectious agent is known as: Hygiene Vaccination Herd immunity Immunity

Immunity

A disease has an incidence of 10 per 1,000 persons per year, and 80% of those affected will die within 1 year. Prior to the year 2000, only 50% of cases of the disease were detected by physician diagnosis prior to death. In the year 2000, a lab test was developed that identified 90% of cases an average of 6 months prior to symptom onset; however, the prognosis did not improve after diagnosis. Comparing the epidemiology of the disease prior to 2000 with the epidemiology of the disease after the development of the lab test, which statement is true concerning the disease in 2000? Incidence is higher and prevalence is higher than in 1999 Incidence is higher in 2000 but prevalence remains the same Incidence is the same in 2000 but prevalence is higher than in 1999 Both incidence and prevalence remain the same as in 1999

Incidence is higher and prevalence is higher than in 1999

A study found that adults older than age 50 had a higher prevalence of pneumonia than those who were younger than age 50. Which of the following is consistent with this finding? Younger adults have a higher incidence of pneumonia Older adults have a higher case-fatality rate from pneumonia Younger adults with pneumonia are more likely to report being ill than older persons Incidence rates do not vary by age, but older adults have pneumonia for a longer duration compared to younger adults

Incidence rates do not vary by age, but older adults have pneumonia for a longer duration compared to younger adults

For colorectal cancer diagnosed at an early stage, the disease can have 5-year survival rates of greater than 80%. Which answer best describes early stage colorectal cancer? Incidence rates and mortality rates will be similar Mortality rates will be much higher than incidence rates Incidence rates will be much higher than mortality rates Incidence rates will be unrelated to mortality rates

Incidence rates will be much higher than mortality rates

Among those who are 25 years of age, those who have been driving less than 5 years had 13,700 motor vehicle accidents in 1 year, while those who had been driving for more than 5 years had 21,680 motor vehicle accidents during the same time period. It was concluded from these data that 25-year-olds with more driving experience have increased accidents compared to those who started driving later. This conclusion is: Correct based on the data Incorrect because rates are not reported Incorrect because prevalence estimates are given when incidence rates should be reported Incorrect because there are no comparison groups identified

Incorrect because rates are not reported

Which of the following statements pertains to relative survival? Refers to survival of first-degree relatives Is equal to the case-fatality rate Is generally closer to observed survival rates in younger age groups Is generally closer to observed survival rates in older age groups

Is generally closer to observed survival rates in younger age groups

A disease has an incidence of 10 per 1,000 persons per year, and 80% of those affected will die within 1 year. Prior to the year 2000, only 50% of cases of the disease were detected by physician diagnosis prior to death. In the year 2000, a lab test was developed that identified 90% of cases an average of 6 months prior to symptom onset; however, the prognosis did not improve after diagnosis. Which statement is true concerning the duration of the disease after the development of the lab test? Mean duration of a case of the disease is shorter in 2000 Mean duration of a case of the disease is the same in 2000 Mean duration of a case of the disease is longer in 2000 No inference about mean duration can be made since the lab test has only been available for 1 year

Mean duration of a case of the disease is longer in 2000

The population of a city on February 15, 2005, was 36,600. The city has a passive surveillance system that collects hospital and private physician reports of influenza cases every month. During the period between January 1 and April 1, 2005, 2,200 new cases of influenza occurred in the city. Of these cases, 775 persons were ill with influenza according to surveillance reports on April 1, 2005. The monthly incidence rate of active cases of influenza for the 3-month period was: 4 per 1,000 population 17 per 1,000 population 20 per 1,000 population 39 per 1,000 population 130 per 1,000 population

20 per 1,000 population

For a disease such as liver cancer, which is highly fatal and of short duration, which of the following statements is true? Choose the best answer. Mortality rates will be much higher than incidence rates Mortality rates will be much higher than prevalence rates Incidence rates will be much higher than mortality rates Case-fatality rates will be equal to mortality rates Incidence rates will be equal to mortality rates

Incidence rates will be equal to mortality rates

Which of the following is a measure of disease prognosis? Prevalence Median survival time Age-adjusted mortality rates Standardized mortality ratio

Median survival time

Which of the following is an advantage of active surveillance? Requires less project staff Is relatively inexpensive to employ More accurate due to reduced reporting burden for health care providers Relies on different disease definitions to account for all cases

More accurate due to reduced reporting burden for health care providers

In a country with a population of 16 million people, 175,000 deaths occurred during the year ending December 31, 2005. These included 45,000 deaths from tuberculosis (TB) in 135,000 persons who were sick with TB. Assume that the population remained constant throughout the year. Not all 135,000 cases of TB were contracted during 2005. Which of the following statements is true? The case-fatality rate provides a reasonable estimate of incidence The prevalence of TB for 2005 is equal to the denominator of the case-fatality rate The duration of TB is brief All of the above None of the above

None of the above

In comparing the mammography readings of two technicians who evaluated the same set of 600 mammograms for presence of breast cancer from a generally representative sample of women from the population, Agreement regarding negative or normal mammograms is likely to be low The kappa statistic measures agreement due to chance only Overall percent agreement calculated for both readers may conceal significant disagreements regarding positive tests A kappa of 0.9 would be unsatisfactory A kappa of 0.6 represents poor agreement

Overall percent agreement calculated for both readers may conceal significant disagreements regarding positive tests

Which of the following statements are true? More than one answer may be correct. Prevalence rates are always larger than incidence rates In a steady state, the prevalence of disease is equal to the attack rate Diagnostic criteria rarely impact estimates of disease prevalence and incidence Prevalence rates are useful for public health planning Incidence rates can be used to estimate prevalence when the mean duration of the disease is known

Prevalence rates are useful for public health planning Incidence rates can be used to estimate prevalence when the mean duration of the disease is known

What would be the effect on age-specific incidence rates of uterine cancer if women with hysterectomies were excluded from the denominator of incidence calculations assuming that most women who have had hysterectomies are older than 50 years of age. The rates in all age groups would remain the same. Only rates in women older than 50 years of age would tend to decrease. Rates in women younger than 50 years would increase compared to women older than 50 years of age. Rates would increase in women older than 50 years of age but may decrease in younger women as they get older. It cannot be determined whether the rates would increase or decrease.

Rates would increase in women older than 50 years of age but may decrease in younger women as they get older.

The population of a city on February 15, 2005, was 36,600. The city has a passive surveillance system that collects hospital and private physician reports of influenza cases every month. During the period between January 1 and April 1, 2005, 2,200 new cases of influenza occurred in the city. Of these cases, 775 persons were ill with influenza according to surveillance reports on April 1, 2005. What can be inferred about influenza cases occurring in the city? Active surveillance would enable better prevention of influenza The incidence rate would decrease if active surveillance were employed The average duration of influenza is approximately 1 month The actual number of influenza cases occurring in the population is less since hospitals and private physicians may be reporting the same patients.

The average duration of influenza is approximately 1 month

Which of the following characteristics indicate that mortality rates provide a reliable estimate of disease incidence? More than one answer may be correct. Case-fatality rate is low The case-fatality rate is high The duration of disease is short The prevalence of disease is greater than 5%

The case-fatality rate is high The duration of disease is short

The prevalence rate of a disease is two times greater in women than in men, but the incidence rates are the same in men and women. Which of the following statements may explain this situation? The duration of disease is shorter in women Men are at greater risk for developing the disease The case-fatality rate is lower for women The age-adjusted mortality rate will be higher for women The proportionate mortality rate for the disease is higher for men

The case-fatality rate is lower for women

Which of the following is characteristic of a single-exposure, common-vehicle outbreak? Long latency period before many illnesses develop There is an exponential increase in secondary cases following initial exposures Cases include only those who have been exposed to sick persons The epidemic curve has a normal distribution when plotted against the logarithm of time

The epidemic curve has a normal distribution when plotted against the logarithm of time

A disease has an incidence of 10 per 1,000 persons per year, and 80% of those affected will die within 1 year. Prior to the year 2000, only 50% of cases of the disease were detected by physician diagnosis prior to death. In the year 2000, a lab test was developed that identified 90% of cases an average of 6 months prior to symptom onset; however, the prognosis did not improve after diagnosis. Which statement is true concerning the disease-specific mortality rate after the development of the lab test? The mortality rate for the disease is decreased in 2000 The mortality rate for the disease is the same in 2000 The mortality rate for the disease is increased in 2000 No inference about the mortality rate can be made since the lab test has only been available for 1 year

The mortality rate for the disease is the same in 2000

Which of the following are examples of a population prevalence rate? The number of ear infections suffered by 3-year-old children in March, 2006 The number of persons with hypertension per 100,000 population The number of cases of skin cancer diagnosed in a dermatology clinic b and c

The number of persons with hypertension per 100,000 population

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 ageand race-matched men all of whom showed no cancer at biopsy. The results of the PSA screening test in each group is shown in the table. The PSA screening test is used in the same way in two equal-sized populations of men living in different areas of the United States, but the proportion of false positives among those who have a positive PSA test in the first population is lower than that among those who have a positive PSA test in the second population. What is the likely explanation for this finding? It is impossible to determine what caused the difference The prevalence of disease is higher in the first population The specificity of the test is lower in the first population The specificity of the test is higher in the first population

The prevalence of disease is higher in the first population

Which of the following is a key assumption involved in the use of life-table analysis? The risk of disease does not change within each interval over the period of observation There are no losses to follow-up in the study population The frequency of exposure is similar in treatment and comparison groups The disease is common

The risk of disease does not change within each interval over the period of observation

In a community-based hypertension testing program called HT-Aware, the detection level for high blood pressure is set at 140 mmHg for systolic blood pressure. A separate testing program called HT-Warning in the same community sets the level at 130 mmHg for high systolic blood pressure. Which statements are likely to be true? The sensitivity of HT-Warning is greater than that of HT-Aware The specificity of HT-Warning is greater than that of HT-Aware The number of false positives is greater with HT-Warning than with HT-Aware The number of false negatives is greater with HT-Warning than with HT-Aware The sensitivity and specificity are the same for both tests

The sensitivity of HT-Warning is greater than that of HT-Aware The number of false positives is greater with HT-Warning than with HT-Aware

Test A has a sensitivity of 95% and a specificity of 90%. Test B has a sensitivity of 80% and a specificity of 98%. In a community of 10,000 people with 5% prevalence of the disease, Test A has always been given before Test B. What is the best reason for changing the order of the tests? The net sensitivity will be increased if Test B is given first The total number of false positives found by both tests is decreased if Test B is given first The net specificity will be decreased if Test B is given first The total number of false negatives found by both tests is decreased if Test B is given first

The total number of false positives found by both tests is decreased if Test B is given first

Which of the following is a condition which may occur during the incubation period? Onset of clinical illness Receipt of infection Signs and symptoms of disease Transmission of infection

Transmission of infection

A survival study was conducted in a population of oncology patients treated with a new chemotherapeutic agent. The probability of surviving the first year (P1) is 0.50. The probability of surviving the second year (P2) is 0.45, and the probability of surviving the third year (P3) is 0.40. What is the cumulative probability of surviving all three years?

(P1* P2* P3) = 0.50 * 0.45 * 0.40 = 0.09 or 9%

Which of the following is the number of persons who died from a specified disease among all persons with the disease? A. Case-fatality rate B. 5-year survival rate C. Observed survival rate D. Median survival rate E. Relative survival rate

A. Case-fatality rate

Annual influenza vaccination is an example of... A. Primary prevention B. Secondary prevention C. Tertiary prevention

A. Primary prevention

A mortality rate is a good index of incidence when... A. The case-fatality rate is high and duration is short B. The case-fatality rate is high and duration is long C. The case-fatality rate is low and duration is short D. The case-fatality rate is low and duration is long

A. The case-fatality rate is high and duration is short

With passive surveillance, local and state health departments rely on health care providers or laboratories to report cases of disease A. True B. False

A. True

In a population of 1,000 male dye workers, there were 15 deaths from bladder cancer in 1955. The expected number of bladder cancer deaths in the general population in 1955 was 7 deaths. What is the standardized mortality ratio (SMR)? A. (7/25) *100 = 28% B. (15/7) *100 = 214% C. Not enough information has been provided

B. (15/7) *100 = 214%

Associations between an exposure and disease (or health-related outcome) imply causality. A. TRUE B. FALSE

B. FALSE

Disease prevention is achieved through... A. Population-based (public health) approach B. High-risk (often requires a clinical action) approach C. Both D. Neither

C. Both

Which of the following mortality measures tells us what percentage of people, who have a certain disease, will die from that disease? A. Cause-specific mortality rate B. Proportionate mortality C. Case-fatality rate D. None of the above

C. Case-fatality rate

Who took cowpox material from a lesion on the hand of a dairy maid and inoculated an 8 year old "volunteer"... A. Hippocrates B. John Snow C. Edward Jenner D. Ignaz Semmelweis

C. Edward Jenner

Which of the following is an estimate of the probability of surviving all causes of death for a specified time interval? A. Case-fatality rate B. 5-year survival rate C. Observed survival rate D. Median survival rate E. Relative survival rate

C. Observed survival rate

The leading cause of death in 1900 was... A.Cancer B.Heart Disease C.Pneumonia and influenza D.Stroke E.None of the above

C.Pneumonia and influenza

County A has 500 cases of a rare, highly infectious disease. County B has 100 cases of disease. Is the risk of disease in County A... A. Higher than County B B. Lower than County B C. The same as County B D. Not enough information is provided

D. Not enough information is provided

Which of the following is expressed as the ratio of the observed to the expected survival time? A. Case-fatality rate B. 5-year survival rate C. Median survival rate D. Relative survival rate

D. Relative survival rate

Epidemiology is.... A.A Greek word meaning the doctrine of what is among or upon the people B.The study of the distribution and determinants of health-related states or events in specified human populations and the application of this study to control health problems C.The study of skin disease D.Both A and B E.None of the above

D.Both A and B

A fundamental assumption of epidemiology is... A.Human disease is randomly distributed B.Human disease is not randomly distributed C.Human disease has causal and preventive factors that can be identified through systematic investigation of human populations D.Both A and C E.Both B and C

D.Both A and C

Case-fatality rates, 5-year survival rates, observed survival rates, median survival rates and relative survival rates are used to express ____________.

prognosis