Practice Flashcards
Q: Which of the following is the only measure of disease occurrence which can be obtained from cross-sectional studies?
Incidence Prevalence Mortality Morbidity Case
A: Prevalence
Q: The prevalence is:
- the number of new cases of a disease in a specific time
- incidence - duration
- incidence x duration
- the probability that a person will develop a particular disease
- the cause of a particular disease
A: incidence x duration
Q: Which of the following is an advantage of a case-control study?
- Can look at multiple outcomes
- Can follow through the natural course of the disease
- Can calculate incidence
- Good to look at rare exposures
- Can examine effects of multiple exposures
A: Can examine effects of multiple exposures
Q: If 5 out of 20 smokers get lung cancer in a year, compared to 1 out of 20 non-smokers, what is the excess fraction?
80% 20% 25% 75% 5%
A: 80%
The excess fraction (or attributable fraction) indicates what proportion of the risk in a person exposed to a risk factor is attributable to that factor. In this case, 4 out of 5 (80%) of the lung cancer cases amongst smokers can be attributed to smoking, and so 80% of lung cancer cases amongst smokers could be eliminated if they did not smoke.
Q: The mathematical relationship between odds and probability is:
- Odds = probability - (1/probability)
- Odds = probability
- Odds = probability / (1-probability)
- Odds = 1 / probability
- Odds = probability + (1/probability)
A: Odds = probability / (1-probability)
Q: The Standardised Mortality Ratio is:
- A type of case-control study
- A rate ratio adjusted for age
- The number of observed deaths in a population over a given time
- The number of expected deaths in a population over a given time
- An outdated and useless measure to modern epidemiologists
A: A rate ratio adjusted for age
The SMR is the number of observed deaths / the number of expected deaths if experienced the same age-specific rates as the standard population. It is therefore a rate ratio adjusted for age.
Q: The most common way of presenting results from a meta-analysis is using a:
- Forest Plot
- Bar graph
- Funnel Plot
- Line graph
- Galbraith Plot
A: forest
A Forest Plot shows the results from each study in a meta-analysis and the combined result.
Q: The most common way of exploring heterogeneity in meta-analyses is using a:
- Forest Plot
- Bar graph
- Funnel Plot
- Line graph
- Galbraith Plot
A: galbraith
Q: The fixed effects and random effects models are used in:
- Cohort studies
- Case-control studies
- Systematic reviews
- Meta-analyses
- Randomised controlled trials
A: Meta-analyses
Q: What is the size of each box proportional to in a forest plot?
A: The larger a box is, the more weight is given to that individual study.
Q: What would you look at to identify the 95% confidence intervals of each individual study (in forest plot)?
A: whisker width
Q: Blinding in a clinical trial helps to remove what type of bias?
A: measurement
Q: How often does the UK Census take place?
A: every 10 yrs
Q: Of the following, which is the most commonly diagnosed cancer in the UK?
Large bowel Stomach Liver Kidney Bladder
A: large bowel
Other commonly diagnosed cancers in the UK include lung and breast cancer
Q: Screening for high blood pressure in older people is an example of which type of screening?
- Mass, systematic
- Mass, opportunistic
- Targeted, systematic
- Targeted, opportunistic
A: Mass, opportunistic
It is “mass” because it applies to the whole population, and “opportunistic” because the opportunity to undergo screening occurs when the patient presents to the doctor or health care professional for another reason.
