Research & Evidence-Based Medicine

20 learning units • 100 chapter sections • 200 explained questions. Build a question, judge the evidence and connect the answer with the person receiving care.

Original RAHBAR study material for the Year 3 learning pathway. Educational examples support supervised learning; institutional research and clinical requirements still apply. References & further reading ↓

MODULE 10 / 20

Randomised Trials & Fair Comparisons

Appraise treatment assignment, follow-up and analysis before trusting a trial’s conclusion.

Choose an answer and check it immediately. Change your choice to try again. This is a self-study exercise; results are not saved.

Question 01. Which allocation method is genuinely chance based? A. Alternating patientsB. Assigning by birth monthC. A properly generated unpredictable random sequenceD. Allowing the recruiter to choose

Question 02. What does allocation concealment prevent? A. Foreknowledge of the next assignment during recruitmentB. Every adverse event after treatmentC. All missing outcomesD. All statistical uncertainty

Question 03. How does blinding differ from allocation concealment? A. It limits knowledge of assigned treatment after allocationB. It is exactly the same recruitment safeguardC. It generates the sampling frameD. It determines the sample mean

Question 04. Which statement best describes intention-to-treat comparison? A. Analyse only fully adherent respondersB. Move all crossovers to their received treatment groupC. Exclude every participant with an adverse eventD. Analyse participants in their originally assigned groups

Question 05. Does intention-to-treat analysis make missing outcomes harmless? A. No, assumptions and sensitivity analyses remain necessaryB. Yes, the label supplies all missing valuesC. Yes, randomisation measures unobserved outcomesD. Only if the article is short

Question 06. Why report who was blinded? A. Every double-blind trial masks identical peopleB. It replaces the need for randomisationC. It determines the p-value automaticallyD. Broad labels may hide different masking arrangements

Question 07. Equal loss-to-follow-up percentages occur in both groups. What should be checked? A. Nothing, bias is impossibleB. Only the font of the flow diagramC. Only the allocation ratioD. Reasons for losses and their relation to outcomes

Question 08. What is a key concern in a crossover trial? A. Absence of all repeated observationsB. Carryover from the earlier treatment periodC. Automatic elimination of time effectsD. Guaranteed applicability to irreversible cures

Question 09. Why may a per-protocol comparison become biased? A. It always retains perfect random balanceB. It includes only random missingness by definitionC. It prohibits all subgroup differencesD. Adherence can be related to prognosis

Question 10. Which information should accompany a trial’s benefit estimate? A. Only the favourable abstract sentenceB. Only the funding logoC. Harms, uncertainty and follow-up durationD. Only the number of tables

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References & Further Reading

Use the full methods and relevant chapters when appraising a paper. These sources support further study; the examples and questions above are original teaching exercises.

Reference review: 25 September 2026. Consult current institutional guidance for project approval and clinical decisions.