What do we mean by study designs?
- Type and level of research evidence
- A broad description of how the study was done
- Level is indicative of, but not equal to, quality
- Diff representations of level exist
Study designs include
Systematic review Review Randomised study/ randomised controlled trial Non randomised trial Case control Cohort study Case study
What is a systematic vs narrative review?
- S = broad search for primary evidence (2 or more databases) and N = may be no description of how the search was done or it may be restrictive
- S = pre determined criteria to decide on included studies and N = criteria not stated
- S= independent decisions on which studies to include and independent appraisals and N = may include only one researcher or researchers may not have worked independently
- Cochrane reviews are systematic but SRs are also published elsewhere, and narrative reviews wouldnt get into the Cochrane database
What is a meta analysis?
This is the analysis of data from several individual studies, making the result more powerful (more likely to be true statistically)
-If you want to find a systematic review, a meta analysis is also relevant as a systematic review often includes a meta analysis, and so this term may be used instead
A randomised study vs non randomised?
- R = study includes 2 or more participant groups and NR = includes one or more participant groups
- R = participants have been randomly allocated to groups and NR = participants have been allocated to groups in a non random ways
- R = groups treated differently or NR = only one group (no control) or a historic control is used
Case control studies v Cohort studies?
- CC= two or more groups of participants and C = a group of participants is observed over a period of time to determine whether a particular outcome occurs
- CC = two groups differ, on has an outcome eg the case/ disease and the other is a control, C = participants analysed for risk factors that exist in those who develop the outcome
- CC = Participants analysed for risk factors differing bet groups and C = prospective study, looks forward over time
- CC = retrospective study, looking back over time
Other ways of describing study design?
- Qualitative or quantitative
- Observational studies
- Mixed method studies
What are qualitative and quantitative study designs?
Outcome is measured qualitatively eg descriptions by individuals or focus group, or quantitatively eg VA measurement, reading speed or symptom score
What are observational studies?
Observing the px without deliberate intervention eg we wouldnt ask people to smoke but could observe those who do. Case control and observational studies are observationals
What are mixed method studies?
Diff approaches used within one study eg both qualitative and quantitative
