Chapter 5

How to Read Scientific Articles

6 videos · about 41 minutes · watch as a YouTube playlist →

  1. 1What kind of paper is this?Reading a paper and appraising one are different skills. Where evidence-based medicine came from, and the first skill it asks for: classifying a study by design in about a minute.6 min
  2. 2Read the methods first, and find where bias entersQuestion, design, participants, comparison, outcomes, transparency — the frame for appraising any study. Then the hard idea: confounding is what you failed to adjust for, selection bias is who ended up in the study, and only one of them can be fixed by statistics.6 min
  3. 3A real methods section, read out loudA published methods section worked through line by line, with the reader’s own questions left in: why randomize districts rather than children, what a two-thirds completion rate does to the comparison, and why particular outcomes were named in advance.7 min
  4. 4Effect sizes, confidence intervals, and how results get misreadWhy the interval carries more information than the p-value, worked through two risk ratios where a non-significant result is consistent with a 40% reduction, no effect, and a 5% increase at the same time.5 min
  5. 5Reading tables and figuresFour real figures from one study: a baseline table with shifting denominators, a regression table with unadjusted against adjusted odds ratios, Kaplan-Meier curves, and a flow diagram that starts at 12,064 patients and ends at 10,102.9 min
  6. 6Qualitative rigor, and reading the discussion like a skepticQualitative work judged on its own terms — informational richness rather than representativeness, and why one quote from one person is an anecdote rather than a theme. Then the discussion section: the slip from associated with to leads to, and what authors leave out.9 min

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