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Reading and evaluating the scientific and medical literature. Robert Silbergleit, MD Department of Emergency Medicine. Reading Philosophy Habit Strategies. Evaluating Question Design Other Bias Statistics. Goals. Philosophy. The scientific literature is a discussion. Philosophy.
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Reading and evaluating the scientific and medical literature Robert Silbergleit, MD Department of Emergency Medicine
Reading Philosophy Habit Strategies Evaluating Question Design Other Bias Statistics Goals
Philosophy The scientific literature is a discussion
Philosophy Data are plentiful but truth is elusive
Habit • You must read.
Habit • You must read. • There is too much to read.
“It’s all right, sweetie. In the information age, everybody feels stupid.”
Strategies • Strategies for reading • Grazing • Searching • Delivery
Strategies • Information age strategic aids. • On-line journals • Weekly search agents • Traditional strategic aids. • Review articles • Lectures • Journal clubs
Strategies • Putting it together- a clinician’s strategy • NEJM (or JAMA or BMJ) • Clinical specialty journal (or 2) • Special interest or subspecialty journal • Abstract service
Strategies • A research scientist’s strategy • Science (or Nature) • A research focus journal (or 2) • A weekly literature search agent
Strategies • Pitfalls • Intimidation • Education that is not education • Honor and beware the opinion leaders
Strategies • Strategies for skimming • Table of contents • Abstract (don’t believe it) • Figures (or Results text) • Methods • Intro and discussion
Abstracts were found to contain errors or inaccurately represent the article 48% of the time, and ranged from 18% in one journal to 68% in another. JAMA 1999;281:1110
Evaluating • Assessing quality • Being critical • Determining value
Question • Did they ask the right question? • Did they answer the right question? • Is the outcome they measured the one they are interested in?
Question • What makes a good outcome measure? • Meaningful • Accurate (Gold standard) • Objective • Distinct
Question • Is the correct population studied, or the appropriate animal model used? • Referral bias • Species differences
Design • Randomized and controlled • Observational (cohort, case-control)
Bias In science we mean: • Any systematic uncontrolled influence on data that favors a particular result.
Bias But sometimes it really is the lay definition: • A preference or inclination that inhibits impartial judgment.
Bias • Publication bias • Spectrum bias
Statistics • Clinical v. statistical “significance” • Hypothesis testing and the p-value • Multiple comparisons • Regression and confounding
Take home points Science is a discussion Make scientific reading a habit Be skeptical, don’t be cynical