Epidemiology and Study Designs Quiz

As a manager in a large hospital you are trying to assess whether the working hours of surgeons influence the occurrence of complications during operations. More specifically, you want to know whether major postoperative bleeding events are more likely to occur when the surgeon had an evening/night shift in the 48 hours prior to the operation. Which study design would be least appropriate for this research question?

• Case-control study

• Case-crossover study

• Cohort study

Which of the following statements describes the relationship between epidemiology and population health management?

• Epidemiology is a sub-specialisation of population health management

• Population health management is a sub-specialisation of epidemiology

• Knowledge of epidemiological concepts is important to perform research in population health management

• Epidemiology is primarily suited for population health management issues regarding infectious diseases

What is an advantage of direct standardisation?

• When using the same standard population, the standardised rates can be readily compared across populations

• Weight-specific (e.g. for each age group when age-standardising) rates are not required

• It allows us to calculate the standardised mortality ratio

• All of the above

Select the correct statement concerning the strength of association between an exposure and an outcome:

• A relative risk of 20.0 has the same strength of association as a relative risk of 0.05

• A randomised controlled trial is more likely to show a stronger strength of association then a retrospective cohort study.

• The closer the odds ratio is to one, the stronger the strength of association is.

• An odds ratio of 0.7 has a weaker strength of association than a relative risk of 0.7

Researchers want to know whether low birth weight is associated with the occurrence multiple sclerosis (MS) in adulthood, a rare disease with a prevalence of 150 per 100,000 individuals. The researchers should conduct a (select the best answer):

• RCT with low birth weight and normal birth weight as the two arms.

• Case-control study with MS patients as cases and subjects without MS as controls

• Retrospective cohort study with low birth weight as one arm and normal birth weight as the other arm.

• Retrospective cohort study with MS as one arm and no MS as the other arm.

We can reduce the effect of regression to the mean either in the study design or data analysis phase. Which of the following approaches will likely be the most effective?

• Randomisation with control group (study design phase)

• Select subjects after multiple measurements (study design phase)

• Analysis of covariance (ANCOVA, analysis phase)

• None of the above

You want to study the relationship between smoking and frailty. For this, you have cross-sectional data available from a cohort of patients with Alzheimer’s disease. What is the most important problem with using a cohort of patients with Alzheimer’s disease for this study?

• There may be selection bias based on the study population with Alzheimer’s disease

• There may be loss to follow-up due to Alzheimer’s disease

• There is no problem with using a cohort of patients with Alzheimer’s disease

• There may be confounding due to the Alzheimer’s disease

The appropriate method to assess differences in cumulative survival is:

• A randomised controlled trial

• Standardisation

• Standardized Mortality Ratio (SMR)

• The Kaplan-Meier approach

Which of the following statements applies to Bayes’ theorem?

• Based on prior knowledge, one can assess the likelihood of the presence of disease more precisely than without prior knowledge

• Bayes’ theorem does not allow us to infer causality

• Many clinicians unconsciously apply Bayes’ theorem in their daily practice

• All of the above

Using the PICO method, which of the following items is least well defined in the following research question: “We set out to examine whether automated registration of opioid prescriptions reduced the number of chronic opioid users among individuals recovering from hip-replacement surgery.”

• P

• I

• C

• O