Week 3 revision Flashcards
*What is the statistics for how many RCTs are conducted in the LIMC?
In 2007, 85% of RCTs on priority mental
disorders done in HIC, only 1% in LIC. >2/3
of LMIC trials in China (primarily on
schizophrenia).
Name some of the details about trial and cohort studies?
Identify a cohort of participants, using identical inclusion criteria
• Measure exposure to the risk factor / intervention
• Follow participants up over time
• Measure outcome
• Compare outcomes between those who are exposed / unexposed to the risk
factor / intervention
Why it is important to randomise?
Confirmation bias.
Illusion of control.
Without control group we would not know if the patients would recover anyway.
Change due to a placebo effect?
Regression to the mean.
Benefits of RCT?
Prospective.
control for known and unknown confounders.
can control exposure.
Describe efficacy (explanatory trials)
Potential effectiveness under ideal/tightlycontrolled conditions
• Good for answering causal questions
• Lots of exclusion criteria
• Ensure intervention delivered as intended
• Only analyse data for participants who
received the intervention as intended
• Typically uses clinical outcome measures
• Low external validity
Describe effectiveness-(pragmatic) trials.
Effectiveness under realistic conditions
• Good for assessing real-world impact in practice
• Minimal exclusion criteria
• Intervention delivered as it would be in practice
• All participants’ data included, regardless of
how much of the intervention they received
• May use quality of life or user-defined outcome
measures
• High external validity
Outcome measures
What outcome measure is used is critical to what you conclude
• Outcome measures can be simple and easy to collect (e.g. relapse, admission) or more
complex (quality of life, disability, carer impact)
• Measures should be relevant to the setting and informed by priorities of target
population
