Evidence-based medicine (EBM)

• this group is compared to the experimental group (which receives a new
treatment), to measure the effectiveness of the treatment
Crossover study design
• a type of study in which more than one treatment is administered to the
same group of participants in a successive fashion
• two problems can occur: carry-over effects (the effect of one treatment
carries over into the second treatment period) and order effects (the order
in which the treatments are administered may affect the outcome)
Cross-sectional study
• a type of study in which a population is observed over a specifi c time interval
or at a single point in time (often referred to as a “snapshot” study)
• the participants’ exposure to potential risk factors and development of
the outcome of interest are determined simultaneously
Double blind
• studies in which neither the participants nor the researchers know the
group (control or experimental) to which the participants were allocated
(until the end of the study)
Effect size
• the estimate of the magnitude of the observed effect in a study
• generally, the larger the effect size, the greater the effect of the treatment
Epidemiologic Studies
• studies that look at the percentage of people who are affected by a
particular outcome of interest (e.g. disease, disorder, occurrence, etc.)
Epidemiology
• the study of the distribution, determinants and deterrents of morbidity
(illness) and mortality (death)
• that is, the study of who gets sick or dies, where they get sick or die, and
when they get sick or die (distribution), what causes people to get sick or
die (determinants) and what prevents these outcomes (deterrents)
Experimental group
• one of the groups of participants in a study
• this group receives the new treatment that is being studied
• this group is compared to the control group (which receives a placebo
or a previously established effective treatment) in order to measure the
effectiveness of the new treatment
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FOR PATIENTS