Essential Epidemiology, 3rd Edition: Webb, Bain & Page (Chapter 2 – 15 Test Bank)

(Essential Epidemiology)

CHAPTER 2
In a study of 500 patients with coronary heart disease, 100 already had diabetes when the study started on 1 January 2014. Over the next year, 50 more developed diabetes. (Assume the diabetes is permanent and there are no losses or entries to the group of patients with heart disease.)

What is the prevalence of diabetes at the start of 2014?
What is the incidence proportion of diabetes in the same study?
At the beginning of 1999, 2.3% of the Australian population were … infected with Hepatitis C virus (HCV). During the year 1999, a further 16,000
What is the difference between the incidence proportion and the incidence rate?
A new treatment is developed that prevents death but does not produce recovery from a previously lethal disease. Which of the following will occur?
A study aims to determine the incidence and prevalence of a particular disease within the local government area of Winchelsea. What factors would decrease the prevalence of the disease within this study catchment area?
The following table shows data from an epidemiological study. What is the incidence rate among those who are … to the factor under study?
According to the table below, which food is the most likely cause of the outbreak of food poisoning?
The following are all characteristics of the prevalence of a disease except one, which one?
Community A and community B both have crude mortality rates for ischaemic heart disease (IHD) of 4 per 1000 population per year but the age‐adjusted IHD mortality rate in community A is 5 per 1000 population compared to 3 per 1000 population in community B. Which of the following is correct?
A 50 year old Australian male is watching the news in 2014 and hears that the current life expectancy for males has risen to 80 years. Does this mean he can expect to live for another 30 years?

CHAPTER 3

Descriptive epidemiology encompasses which of the following?
Vital statistics are important sources of data on which of the following? (Select all that apply)
Potential sources of data on morbidity in the population at large include which of the following? (Select all that apply)
Many countries now routinely monitor the health of their population through:
In a series of 100 women with breast cancer, 30 reported having a university education. From this we can conclude:
The sample of women with breast cancer in the previous question was drawn at random from all women attending one surgeon’s breast cancer clinic at a private hospital in Montreal, Canada. To which target population might the prevalence result apply?
A controversy occurred between the proponents of drug therapy versus remedial reading for patients with dyslexia. To support their position, one group wrote: “Of 111 patients with dyslexia, 91 showed improvement following remedial reading courses.” Their inference that in patients with dyslexia, remedial reading is the therapy of choice is:
If the age‐adjusted incidence rate of breast cancer among the grandchildren of Japanese immigrants to the USA is much closer to that of American women (high rates) than Japanese women (low rates) what does this tell us?
If an ecological study shows a strong positive correlation between per capita alcohol consumption and breast cancer incidence rates in European countries we can draw the following conclusion:
You are told to … a low‐cost ecological study comparing your country to 20 others, looking at the correlation between meat consumption and coronary heart disease (CHD). Which of the following … features would you incorporate:

CHAPTER 4

In a study … to determine the incidence of hypertension (high blood pressure) in an inner‐city community, a sample of residents is selected for examination. Which of the following sampling methods is likely to lead to the least bias?
Which of the … options maximises the exchangeability of groups being compared to assess whether a given exposure causes a particular disease?
Which of the following is true of a case‐control study?
Controls are … in a case‐control study because:
Which of the … is true in the context of interpreting the results of a case‐ control study compared to a cohort study? (select all that are true)
The following table shows data from an epidemiological study. What type of study was this most likely to … ?
What is/are the main disadvantage(s) of using a cross‐sectional survey to assess the association between marijuana use and schizophrenia? (Select all that apply)
Which of the following methods is the best method to control for confounding through study … ?
In assessing the relative merits of case‐control and cohort studies, which one of the following statements is correct?
In measuring an exposure in a prospective cohort study design, which biases are most readily avoidable?

CHAPTER 5

1000 adults who presented to their local emergency department with a possible heart attack had a blood sample collected for laboratory tests. It was later found that 300 of these people had not had a heart attack and the levels of triglycerides in the blood of this group were compared with the levels among the 700 who had had a heart attack giving the following results:
Which of the following measures is most useful for assessing the potential benefits of a preventive programme?
In the first 12 years of follow‐up of the Framingham Heart Study, the observed number of cases of angina was 1.6 times higher than the number expected based on population rates. What type of measure is this?
The following table shows data from an epidemiological study. What is the rate difference?
What is the population attributable risk in the same study?
A randomised, placebo‐controlled trial was conducted in Indonesia to study the effects of vitamin A in preventing deaths among children with measles. The investigators reported a relative risk of 0.60 for the intervention versus control group. This means that:
To assess the association between Kawasaki syndrome (KS) and carpet shampoo, investigators conducted a case‐control study with 100 cases (children with KS) and 100 controls (children without KS). Among the children with KS, 50 had a history of recent exposure to carpet shampoo. Among the controls, the number with a recent history of exposure to carpet shampoo was 25. For this study, the odds ratio was:
The strength of an association between exposure and disease is best measured by the:
In a study to determine whether tonsillectomy is associated with subsequent development of Hodgkin’s disease, the estimated relative risk for those with prior tonsillectomy was found to be 1.9. From this we can conclude:
Which of the following factors will influence the population attributable fraction? (Select all that apply)

CHAPTER 6

A large study sample size is important because it:
Which of the following relative risks (and 95% confidence intervals) is the most precise?
A study found that the relative risk (RR) for the association between air pollution and asthma was RR=1.5, 95%CI (1.2–1.9) with a P value of 0.001. The likelihood that this association … by chance is:
Which relative risk (RR) estimate(s) in the figure above is/are statistically significant? (Select all that apply)
The data from the studies in the figure come from randomised trials of drug treatments. Which RR estimate(s) is/are most likely to … clinically significant? (Select all that apply)
Which RR estimate could … considered both statistically and clinically significant?
A study that is able to detect a relative risk of 2.0 between an exposure and an outcome 4 times out of 5 has:
Which of the following statements best describes the advantages of confidence intervals over p‐values?
When we conduct an hypothesis test we:
You wish to conduct a case‐control study investigating the association between chewing betel quid (from the areca nut) and oral cancer in Kerala. You estimate that the prevalence of betel quid use in the general population is 20% and based on previous studies you expect an odds ratio (OR) for oral cancer of OR=2.0 associated with betel quid chewing compared to no betel quid chewing. Using the table below, how large a sample (cases and controls) would you want for this study?

CHAPTER 7

You want to assess the effects of physical activity on study habits so you advertise at your local university for people to take part in your study. What type of selection bias might this lead to?
In measuring an exposure in a prospective cohort study design, which biases are most readily avoidable?
To determine attack rates for a respiratory disease of unknown origin among people attending a conference, random samples of guests staying at four hotels were surveyed for subsequent illness. Because it was not feasible to survey all guests, random sampling provided the best information because:
A study was conducted to determine the side effects of 4 anti‐malarial drugs in a group of overseas volunteers in Cameroon. A self‐report questionnaire was given to each participant and participation was voluntary. Each participant was asked to indicate which drugs they had used and the severity of any side effects they had experienced over the past two years. What kind(s) of bias would most likely … present in this study? (Select all that apply)
In prospective cohort studies, why is loss to follow‐up a source of selection bias?
In a hypothetical case‐control study with perfect measurement, the association between occupational resin exposure and lung cancer was OR=1.76. The data for this association is provided in the Table below:
What term best describes the misclassification in the previous question?
What would the OR have been if 10% of cases who were unexposed were misclassified as exposed, but all other groups were measured accurately?
What term best describes the misclassification in the previous question?
In a case‐control study of the association between residence near a hazardous waste site and leukaemia, selection bias is likely to be a problem because:
outcome, and so may lead to spurious associations.

CHAPTER 8

When does confounding occur?
What is the best single way to prevent confounding from affecting the results of a study?
In a study of alcohol and oral cancer the crude relative risk is 4.0 overall but it is 2.0 for men and 2.0 for women when the sexes are considered separately. This suggests that:
Which two of the following methods cannot … used to prevent confounding from occurring in a study?
In a study of illicit drug use and attempted suicide the crude relative risk is 2.1 overall but it is 3.4 for men and 1.3 for women when the sexes are … separately. This suggests that:
An intermediary variable is not a confounder because:
The table below comes from a study of ovarian cancer survival in Australia (Anuradha
et al., 2015).
Why might adjustment for age affect the magnitude of the association between comorbidities and ovarian cancer?
Using the directed acyclic graph below to identify which of the following statements are true? (Select all that apply)
Which of the following statements best describes the potential effects of confounding?

CHAPTER 9 – NOT APPLICABLE

CHAPTER 10

The figure above depicts the only possible causes of a disease X. Using this, which of the following statements is/are true? (Select all that apply)
Which of the following are necessary causes (select all that apply)?
If it is estimated that 25% of cases of a disease can … attributed to poor diet, 30% to poor hygiene, 40% to tobacco smoking and 20% to high alcohol consumption which one of the following statements is true? (Select all that apply)
An effective programme to prevent a chronic disease should target (select one):
Which one of the following statements best describes the Bradford Hill criteria?
Which of Bradford Hill’s criteria must … met for an association to … causal? (Select all that apply)
The Bradford Hill criteria should … applied:
In a study of smoking and ovarian cancer, a history of smoking was strongly associated with one rare type of ovarian cancer (mucinous cancers) but not with any
of the other more common types of ovarian cancer. This pattern of results suggests (select the best option):
The results of a case‐control study showed a strong and statistically significant association between high triglyceride levels and heart attack that persisted after adjusting for age, sex, gender and blood cholesterol levels so the investigators concluded that the relationship was causal. This conclusion is:

CHAPTER 11

Before starting out to do a systematic review, the most important requirement is:
You are commissioned to write a quantitative systematic review. Which of the following research questions is framed in the most epidemiologically appropriate way?
Having decided on your research question, you establish your criteria for which studies to include. Which (if any) of the criteria listed below should not … a basis for including a study in your review? (Select all that apply)
After applying your inclusion/exclusion criteria you have results for over 100 studies. Which of the following strategies (select all that apply) will help you organise the information about the studies and present the results most clearly?
In a systematic review of aspirin as a possible preventive of lung cancer (Feskanich et al., British Journal of Cancer, 2007 http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2360462/pdf/6603996a.pdf), the authors identified all papers with original data that assessed the relation between aspirin use and lung cancer incidence or mortality (N=18) and then excluded:
You are of course … about the quality of studies included in a systematic review. In general RCTs are the ‘gold standard’ design, especially for interventions, but there are many circumstances when they are infeasible, unethical or otherwise inappropriate. Identify for which of the following research questions an RCT would not … the optimal design.
Which of the following statements about the conduct and reporting of systematic reviews and meta‐analyses are true? (Select all that apply)
The following figure displays results from a systematic review and meta‐analysis of the effects of sun exposure on mental health. The RRs represent the association between higher sun exposure and good mental health. Studies 1, 2 and 5 are cohort studies, 3 and 4 are case‐control studies. They are arranged in order of year of publication, earliest first.
Looking at the same figure (remember that Studies 1, 2 and 5 are cohort studies, 3 and 4 are case‐control studies, and they are arranged in order of year of publication, earliest first), Which of the following statements is/are reasonable? The order in which the studies are presented:
You may have noted that the x‐axis of the plot uses a logarithmic scale (the distance from 1–2 is the same as that from 2–4 and from 4–8). This is:

CHAPTER 12

Which of the following activities form part of public health surveillance? (Select all that apply)
Which of the following might … the subject of a public health surveillance programme? (Select all that apply)
Common uses of public health surveillance include which of the following? (Select all that apply)
Evaluation of a surveillance programme should address which of the following? (Select all that apply)
For surveillance, the public health importance of a disease is determined by which of the following? (Select all that apply)
Which of the following statements describe event‐based surveillance? (Select all that apply)
Which of the following statements could … used to describe sentinel surveillance? (Select all that apply)
Which of the following are forms of surveillance? (Select all that apply)
What is the single most important reason for distributing regular surveillance summaries?
The case definition used for surveillance of a health problem should always … the same as the case definition used for clinical (treatment) purposes.

CHAPTER 13

Which of the following best describes the factors that influence the spread of an infectious disease?
If the latent period for an infection is longer than the incubation period then:
Which of the following can … the reservoir for an infectious disease? (Select all that apply)
Which of the following best defines an outbreak?
In the investigation of an epidemic the most appropriate measure to describe the frequency of occurrence of illness is the:
In the investigation of an epidemic of a fatal disease such as SARS, the most appropriate measure to describe the frequency of death from the disease is the:
If you were investigating an outbreak, in what order would you normally conduct the steps below?
At what point in an outbreak investigation should you start to initiate control and prevention activities?
A spot map is particularly useful for displaying: (Select all that apply)
Clusters of disease can … challenging to investigate because:

CHAPTER 14

Which one of the following options offers the best approach to controlling a chronic disease?
Which of the following actions is not an example of primary prevention?
Campaigns to lower smoking rates and advances in medical and surgical therapies have both helped bring about large declines in mortality from coronary heart disease (CHD) in Canadian men. Which of the following study designs and epidemiological measures could contribute to assessing their relative contributions?
Which one of the following epidemiological measures is likely to … most helpful to a health planner who wants to introduce a primary prevention programme for a disease that is common in the population?
Which one of the following preventive actions reflects a mass strategy approach to prevention?
A ‘high risk’ strategy for prevention:
The multi‐drug polypill to reduce primary and secondary cardiovascular events (CHD and stroke), is mentioned in the text as a possible simple, safe and cheap preventive. Early trials suggest it can improve compliance in patients already taking a number of its component drugs separately; and it is expected there will … results within a year on whether it is effective in reducing blood pressure and serum cholesterol. It will take further years of follow‐up before definitive data on whether it reduces cardiovascular morbidity and mortality are available. Choose the best policy to implement now from among the following options:
When attempting to predict or model the future benefits that might accrue from an effective preventive intervention, should the reference category for the causal agent of interest, e.g. sun exposure or cigarettes, (i.e. the level of exposure to which the intervention aims to shift the population) … :
The Minister for Health has announced that an additional $5 million will … provided to strengthen mental health treatments and services to prevent attempted suicide in the population. You have collected some data on mental disorders and attempted suicide in this population (presented in the table below), and you are asked by the Minister to recommend which disorder should … targeted to ensure the biggest impact on the burden of attempted suicide in the population. Which mental disorder do you recommend?
Which of the following data sources do you think would provide the best data to evaluate how well a national primary prevention programme of behavioural change to decrease the mortality rate from a cancer is working?

CHAPTER 15

Which of the following activities should … part of a public health cancer screening programme? (Select all that apply)
Which of the following characteristics of a disease make it potentially suitable as the target of a screening programme? (Select all that apply)
Which of the factors … below are desirable features of a screening test? (Select all that apply)
Which of the following statements about screening tests are correct? (Select all that apply)
Use the data in the following table to identify which of the following statements are true. (Select all that are true).
About 20% of men who come to autopsy have a cancer in their prostate gland which had not been diagnosed while they were alive, i.e. they did not have clinically‐evident prostate cancer. However, as a result of this undiagnosed cancer they will have had increased blood levels of prostate‐specific antigen (PSA) while they were alive, and this is what screening tests for prostate cancer detect. Given this, if a population‐ based screening programme to detect prostate cancer is introduced, which of the following statements are correct? (Select all that apply)
Which of the following types of study have led to the introduction of a population‐ based screening programme for the cancer in question?
Which of the following conditions need to … met before a population‐based screening programme could … considered as a planning priority? (Select all that apply)
Use the graph below to identify which of the statements below are correct. (Note that the UK breast cancer screening programme began in 1988.) (Select all that apply)
Potential harms from … screened include (select all that apply):