A prospective cohort study investigated the risk of developing diabetes over 10 years. Out of 2,500 participants, 500 were obese, and the rest were not. After 10 years, 100 obese participants developed diabetes, while 50 non-obese participants did. Calculate the relative risk (RR) of diabetes in obese individuals compared to non-obese individuals.

In the UK in 2015, the male population was approximately 31,000,000, of which 2,064,600 were obese. Calculate the prevalence of obesity in this population, expressed as a percentage.

In a case-control study examining smoking and lung cancer, 150 out of 200 cases are smokers, while 100 out of 400 controls are smokers. Calculate the odds ratio (OR) for smoking as a risk factor for lung cancer.

You are conducting a stratified sample of 1,000 participants from a population of 10,000 divided into two strata: 30% men and 70% women. How many men should be included in the final sample?

What is one major advantage of a cohort study over a case-control study?

A study is conducted to test a new intervention for controlling blood glucose levels. Out of 150 participants, 50 were randomly assigned to the intervention group, and 100 to the control group. The intervention group showed a mean reduction of 15 mg/dL in blood glucose, with a standard deviation of 5 mg/dL. The control group showed a mean reduction of 10 mg/dL, with a standard deviation of 7 mg/dL. Calculate the effect size using Cohen’s d.

What is the main purpose of randomization in clinical trials?

A study reports that there were 419 patients with a particular genetic disorder and 59 deaths between 1998 and 2013. What is the case fatality rate, expressed as a percentage?

Which of the following is a key characteristic of an observational study?

What is the key difference between association and causality when considering confounders?