Random allocation can reduce confounding, but the word randomized does not guarantee that a trial is unbiased, clinically important, or applicable to a new population. Read the study from protocol and participant flow through outcome measurement, analysis, and reporting. This guide supports critical reading and is not individualized medical advice.
Translate the question into trial components
Record population, intervention, comparator, outcomes, setting, and follow-up period. Check whether the registered or stated primary outcome matches the headline result. A change from the planned question can create a persuasive finding from selective analysis.
Inspect sequence generation and concealment
Ask how the random sequence was produced and whether recruiters could predict assignments. Random labels without allocation concealment may permit selection into groups. Baseline similarity is useful context, but it does not prove that the randomization process was protected.
Follow every participant
Use the flow diagram to count screened, randomized, treated, followed, analyzed, and excluded participants. Compare loss and reasons across groups. Missing outcomes can bias results when dropout is related to treatment, prognosis, or adverse effects.
Evaluate outcome measurement and blinding
Check whether outcomes were objective or judgment based, who was blinded, when measurements occurred, and whether instruments were validated. Blinding may be impossible for participants yet still feasible for assessors or analysts.
Read effect size before the p value
Record absolute risks, relative effects, confidence intervals, and time horizon. A small p value does not show that an effect is large or meaningful. For harms, examine how events were defined, collected, and reported.
Test applicability and reporting completeness
Compare trial participants, care setting, adherence, comparator, and follow-up with the decision you are considering. Look for protocol deviations, secondary analyses, funding, and conflicts. One trial rarely settles a broad question by itself.
Frequently Asked Questions
Does randomization eliminate all bias?
No. Problems can arise in allocation, attrition, measurement, analysis, and selective reporting after randomization.
Should relative risk be read alone?
No. Pair it with absolute risk, baseline risk, confidence intervals, and follow-up duration.
Can one trial guide a personal treatment choice?
A trial can inform discussion, but individual decisions require clinical context and qualified professional advice.
Put the Reading Into Practice
Choose one published trial. Build a table for randomization, concealment, blinding, participant flow, primary outcome, absolute effect, harms, and applicability. Mark every field that the report does not make clear.
Related Readever Pages
- Explore the AI reading assistant
- Build a nonfiction reading system
- Practice critical reading
- Use the book notes template
