Chapter 11 Flashcards
(17 cards)
What are the 3 levels of a lit review?
Level 1: Reviewing a few papers might provide adequate background
Level 2: Traditional narrative review. - Do not require complete coverage of the literature, have value for critiquing the literature in more depth
Level 3: A major decision regarding a policy or practice should be based on a systematic review and perhaps a meta-analysis of all the relevant literature.
What is a systematic reveiws?
A research method used to summarize and critically analyze the existing literature on a particular research question. Goal is to synthesize all relevant studies and provide an overview.
What is a meta-analysis?
A statistical technique used to combine and summarize the results of multiple studies on a particular topic into a single summary estimate. Allows us to have more more confidence ( the CI will be much smaller. Can make multiple studies that ARE NOT significant into something that IS.
A systematic review involves the following 6 steps
- Specifying the research question.
- Identifying all potentially relevant primary research studies that address the research question.
- Abstracting the data from the primary studies in a standard format.
- Summarizing the findings of the primary studies (might include meta-analysis)
- Critically appraising the quality of the primary studies
- An overall evaluation of the evidence with appropriate conclusions
What is PICOTS?
Framework used to formulate a research question and guide the development of a systematic review. Helps DEFINE AND ORGANIZE key elements of the research question.
What does PICOTS stand for
Population, Intervention, Control, Outcome, Time, Setting
What does P stand for in PICOTS?
Population - Describes the specific gorup of individuals being studied
What does I stand for in PICOTS
Intervention - Refers to the treatment (intervention studies) or exposure (observational studies)
WHat does O stand for in PICOTS
Outcome - describes the effect or results being measured in the study (what is being measured or assesd)
What does C stand for in PICOTS
Control - This is what the intervention is compared agiast, often a control group or an alternative intervention. (What is being comapred)
What does T stand for in PICOTS
Time - The duration over whihc the intervention’s effects are measured. In a cohort study, it refers to the follow up length. In case contorl refers to the lenght of retrospective assesment
What does S stand for in PICOTS
Setting- describes the environment or context in which the study takes place.
What consists main goal of step 2?
To identify all relevant primary studies. Electronic search, Screeming articles done in 2 phases (title and abstract screening then Full text screening (very labour intensive)
What does heterogenity mean for a meta-analysis?
refers to the degree of inconsistency of effects across studies. The most common test is I^2 statistic.
How is I^2 epxressed and what does it mean?
Expressed as a precentage, ranguing from 0-100%, with higher values indicating more heterogenity. 75-100% means a lot of variability between each study
What does publication bias mean?
Refers to the fact that priamryt studies with positive or statistically significant findings are more likely to be published than studies with negative or insignificant results.
2 mian things - Selective acceptance by journals & 2 reserachers more likely to not submit if found a negative result.
What are the levels of hierarchy for primary studies?
Level 1: Evidence from systematic review or meta analysis
Level: Evidence from at least one well-designed RCT
Level 3: Evidence from well-designed control trials without randomisation
Level 4: Evidence from well-designed cohort or case-control
Level 5: Evidence from comparison’s over time
Level 6: Opinions of respected authorities
