L02 - Study designs for healthcare Flashcards
What is the AAAA framework?
Assess - What type of healthcare question/ what type of study
Access - Finding the ‘best’ evidence
Appraise - Evaluating the quality of the evidence, interpreting the results
Act - Is evidence relevant to my clinical practice? Should this evidence change my practice?
What are the different types of descriptive studies?
- Cross sectional studies (surveys)
2. Ecological studies
What is the difference between case report and case studies?
Report - A detailed report of an unusual condition or occurrence in A SINGLE PATIENT
Series - A detailed report of an unusual condition or occurrence in SEVERAL PATIENTS
What are the two types of study designs?
- Observational
2. Interventional or experimental
What is an experimental/ interventional study?
- RF or intervention is deliberately introduced
- RF within investigators control
- Rarely ethical is a known harmful risk factor is involved
What is an observational study?
- The RF or intervention occurred outside the investigators control
- Just ‘observing’ the consequences of a natural exp
What is an ecological study?
- Observational
- Units of obs are groups of individuals rather than the individuals themselves (i.e. popn of different countries or towns)
What are the different types of observational studies?
- Ecological
- Cross sectional
- Case control
- Cohort study (follow up or longitudinal study)
What are the different types of experimental studies?
- Randomised controlled trial (RCT)
Which study type should you use if the clinical question is about frequency and rate?
Cross-sectional; cohort
Which study type should you use if the clinical question is about aetiology and risk factors?
Ecological; case control; cohort
Which study type should you use if the clinical question is about prognosis?
Cohort
Which study type should you use if the clinical question is about diagnosis?
(Special) cross-sectional
Which study type should you use if the clinical question is about effectiveness?
RCT
Which study type should you use if the clinical question is about patient or professional experience?
Qualitative research
What are the different types of bias?
- Selection bias
- Measurement bias
- Attrition bias
Definition of bias?
A systematic error in the design, conduct or analysis of a study that results in a deviation from the truth (the true value)
What is selection bias?
Systematic different in the way the study participants are recruited to a study or are allocated to groups in a comparative study
What is measurement bias?
Systematic difference in the quality (Accuracy) of information/ data gathered from comparison groups in a study
What is attrition bias?
Systematic difference between individuals who stay in a study and those who drop out/ are lost to follow up
