Adjusted analysis1: when groups differ on baseline characteristics (eg, age), analyses of outcome data are statistically modified to account for these differences.
Before-after design: data are collected from the same participants both before and after the introduction of an intervention.
Cohort study: a group of people with a common characteristic or set of characteristics are followed up for a specified period of time to determine the incidence of some outcome; there is no comparison group.
Confidence interval (CI): quantifies the uncertainty in measurement; usually reported as 95% CI, which is the range of values within which we can be 95% sure that the true value for the whole population lies.
Confounder2: a variable that affects the observed relation between 2 other variables (eg, alcohol is related to lung cancer, but does not cause the disease; instead, both alcohol and lung cancer are related to smoking, and it is the smoking that causes lung cancer).
Crossover trial: a method of comparing 2 interventions in …