Evidence-Based Medicine: PICO Format and Search Strategies

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Questions and Answers

What is an advantage of using Google Scholar for searching full-text articles?

More stringent requirements for publication

Less control over search strategy

More user-friendly interface (correct)

Access to more abstract concepts and qualitative research

What is a con of using Google Scholar for searching full-text articles?

Access to fewer full-text articles

Less user-friendly interface

Less control over search strategy (correct)

More stringent requirements for publication

What is a type of pre-synthesized evidence?

Systematic reviews

Meta-analyses

Cochrane Library (correct)

All of the above

What is a limitation of using Trip Database?

None of the above Signup and view all the answers

Why should you use caution when searching for naturopathic topics?

The search results may not be evidence-based Signup and view all the answers

How can you obtain a full-text article if it is not available online?

All of the above Signup and view all the answers

What is a benefit of using the Cochrane Library?

It provides highly rigorous systematic reviews and meta-analyses Signup and view all the answers

What is a disadvantage of using PubMed?

It has less stringent requirements for publication Signup and view all the answers

What is a benefit of using Natural Medicines?

It is available through CCNM library and CAND member website Signup and view all the answers

What is a type of filter or limit that can be used when searching for articles?

All of the above Signup and view all the answers

What was the major outcome of Cochrane's systematic review of corticosteroid treatment in pre-term births in 1987?

It showed that a short course of corticosteroid treatment substantially reduced the risk of premature deaths due to complications. Signup and view all the answers

What is a key component of a clear question in a systematic review?

A clear question that includes the PICO framework Signup and view all the answers

What is the purpose of a heterogeneity test in a systematic review?

To determine if the data is too heterogeneous to combine Signup and view all the answers

What is the purpose of a funnel plot in a systematic review?

To analyze the potential for publication bias Signup and view all the answers

What is the name of the organization that runs the Cochrane Library?

The Cochrane Collaboration Signup and view all the answers

What is an important feature of a comprehensive search strategy in a systematic review?

Searching multiple databases, reference lists, and unpublished studies Signup and view all the answers

Why is it important to assess the individual study quality in a systematic review?

To determine if the studies are similar enough to combine Signup and view all the answers

What is a characteristic of Cochrane reviews?

They are notoriously conservative in their results Signup and view all the answers

What is the purpose of statistical significance testing?

To determine if the results are due to chance Signup and view all the answers

What is the general cut-off for determining statistical significance?

P-value of 0.05 Signup and view all the answers

What is the purpose of a confidence interval?

To provide a range of possible values for the results Signup and view all the answers

What is the effect of a larger sample size on statistical significance?

It increases the likelihood of detecting significance Signup and view all the answers

What is the implication of overlapping confidence intervals?

The results are not significantly different Signup and view all the answers

What is the purpose of calculating the p-value?

To determine the likelihood of the results being due to chance Signup and view all the answers

Why is it important to consider statistical significance in research?

To distinguish between real effects and chance findings Signup and view all the answers

Study Notes

PICO and Searching for Evidence

PICO stands for Population, Intervention, Comparison, and Outcome
A well-structured, answerable question is crucial in finding evidence

Asking an Answerable Question

Unanswerable question: What helps with insomnia?
Structured, answerable question: PICO format
- P: Population (e.g., Marion, a retired woman who flies frequently)
- I: Intervention (e.g., wearing elastic stockings)
- C: Comparison (e.g., not wearing elastic stockings)
- O: Outcome (e.g., reducing the risk of deep vein thrombosis)

Searching for Evidence

Databases used to search for evidence: PubMed, EBSCO, CINAHL, MEDLINE, Google Scholar
PubMed searching:
- Boolean Operators: AND, OR, NOT (capitals important)
- Truncation: * (e.g., hyperten* = hypertension, hypertensive)
- Field descriptions: specify fields to search, e.g., date, author name, journal, title, page number, abstract
- Advanced search builder: helps to be more specific in your search
- MeSH Terms: Medical Subject Headings, controlled vocabulary, specify exactly what you're looking for

Pre-synthesized Evidence

Cochrane Library: HIGHLY rigorous SRs and MAs
Natural Medicines: access through CCNM library and CAND member website
Trip Database: free and upgraded version
Others, subscription: UpToDate, Examine.com

Sourcing Full-Text Articles

Google Scholar
Research Gate
Email the study author: corresponding author, "pre-publication copy"

Practice Exercises

Does the DASH Diet improve blood pressure in adults? If so, by how much?
Can eating blueberries protect against the development of Alzheimer's Disease?
More practice exercises...

Systematic Reviews

A systematic review in 1987 on corticosteroid treatment in pre-term births showed that a short, inexpensive course of corticosteroid treatment substantially reduced the risk of premature deaths due to complications.

Objectives

Recognize the important features and strengths of a systematic review or meta-analysis
Interpret an odds ratio and a forest plot
Design a search strategy to find a systematic review on a topic

Methodology

A clear question is essential (consider PICO)
Search for the right type of studies relevant to the question, with appropriate design (e.g., RCT for interventions)
Conduct a comprehensive search of databases, reference lists, unpublished studies, and contact experts, including non-English studies
Use clear eligibility criteria
Assess individual study quality

Results

Determine if combining results was appropriate, considering study similarity and potential heterogeneity
Use tools like Cochrane Q and I2 to assess heterogeneity
Be cautious of publication bias, attempting to analyze potential bias using individual study data
Use funnel plots to visualize potential bias, seeking symmetrical distribution

Publication Bias

Results of a meta-analysis are only valid if capturing the full range of trial results, avoiding negative studies being overlooked
Analyze individual study data to assess potential publication bias

Cochrane Collection

The Cochrane Collaboration provides systematic reviews in a rigorous and consistent fashion
The Cochrane Library is a reputable, non-biased source of reliable, up-to-date overviews of evidence on specific topics

Cochrane Caution

Cochrane reviews are notoriously conservative in results, often concluding that 'more research is necessary'

Mini Stats Break

Statistical significance determines if a difference is due to chance or a real difference
The P-value represents the odds that the difference is due to chance (e.g., ≤ 0.05 is generally considered significant)
Confidence intervals (CI) provide a range within which the true result is likely to lie (e.g., 95% CI)

Statistical Significance

P-value and confidence intervals are used to determine statistical significance
Variables that influence significance include sample size, variation within and between groups

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Description

Learn to asking answerable questions, identify databases, and search for evidence using PICO format, Mesh terms, and limits. Practice designing and executing search strategies and finding full-text articles. Understand sources of pre-synthesized evidence and more.