Instructions & Tips
- Estimating the Size of the Treatment Effectformulas & explanations of RR, RRR, ARR, & NNT; from Duke
- Sample Therapy Math Worksheetto practice RR, RRR, RD, NNT, & Odds Ratios; from Duke
- Appraisal Resources for EBMRich resource with worksheets, guidance on analysis of different types of studies.
- The NNTQuick summaries of evidence-based medicine
One of the toughest parts of practicing evidence-based medicine is developing a good clinical question. Fortunately, there are many websites, worksheets, & tutorials on this topic.
Clinical questions are often grouped into two main categories: background and foreground questions.
Background questions: Ask for general knowledge about an illness, disease, condition, process or thing
- what causes this disease/disorder?
- how does it present?
- what are some treatment options?
Foreground questions: Ask for specific knowledge to inform clinical decisions and usually concern a particular patient or patient population
Most foreground questions can be formulated in terms of a simple relationship between:
Use the PICO format to help formulate your clinical question for each assignment.
In children with asthma, is the intermittent use of Pulmicort as effective as daily use in preventing asthma exacerbation?
More PICO examples, worksheets, & tutorials
- The Well-Built, Patient-Oriented Clinical QuestionPICO example from Dartmouth Libraries
- Asking Focused Questionsfrom the Center for Evidence-Based Medicine
- PICO Tutorialshort video from Yale
- Forming Clinical QuestionsNice PICO chart with examples for dx, tx, px, and more.
Break your question down into Searchable Concepts
Connect Terms with Boolean Operators
Use a Combination of Keywords & MeSH (or Controlled Vocabulary) in Your Search
Limits or Filters
Use the Filters in PubMed / Ovid Medline to refine your search. You can limit by year, age, type of article, and much more
Types of Questions
The type of question is important and can help lead you to the best study design. To limit your search to a specific study design, use the database's filters/limits or add keywords to your search (e.g., lung cancer AND cohort).
| Type of Question | Best Type of Study |
| Therapy | RCT -> cohort -> case control -> case series |
| Diagnosis | prospective, blind comparison to a gold standard |
| Etiology/Harm | RCT -> cohort -> case control -> case series |
| Prognosis | Cohort study -> case control -> case series |
| Prevention | RCT -> cohort study -> case control -> case series |
Reverse Engineer a Good Article to Find Others (ie. Pearl Growing)
- Find one article relevant to your question
- Yes, you can "google" it.
- It may be an older article or something similar to your topic, but not quite right.
- Paste the title into a peer-reviewed database (PubMed, Ovid Medline, Web of Science, CINAHL)
- Find more articles by
- Incorporating MeSH headings applied to the original article into your search
- Reviewing Similar Articles
- Examining the references cited by the article or, if using Ovid Medline, articles that Cite your original article
- This last technique works if your article is at least a few years old.
- Incorporating MeSH headings applied to the original article into your search
