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What a trial result is allowed to claim

Science · The Human Body · ages 23-24

Name ______________________ Date ____________

Why use concealed random assignment rather than let doctors choose who receives treatment?
- It reduces selection bias in allocating trial treatments.
- It guarantees equal starting risks in each trial.
- It prevents bias from every missing outcome during follow-up.
Which aim is central to a phase 1 drug trial?
- Clinical benefit in all future patient populations
- Early safety, tolerability and dosing
- Routine approval for use in patients without further studies of clinical benefit
When feasible, hiding treatment allocation from participants, care teams and outcome assessors can reduce bias from expectations.
Circle one: True False
In a randomized trial, the drug lowers a blood marker compared with control. No clinical outcomes are measured and no surrogate-validation evidence is supplied. What does this result alone support?
- A marker effect, not proven clinical benefit.
- A survival benefit; clinical tests can be omitted.
- An absence of harm; further safety studies are unnecessary.
By six months, 6 of 100 treated participants and 12 of 100 controls have had at least one stroke. All are followed for six months. What is the relative risk, treatment versus control?
- 2.0
- 6.0
- 0.5
A phase 2 trial does not demonstrate efficacy at the tested dose in the enrolled patients. Which follow-up is best justified?
- Conclude that the target cannot affect this disease.
- Check target biology, exposure, patient selection and trial design.
- Repeat the trial unchanged because safety findings establish efficacy.
A phase 3 trial finding benefit in adults with one disease, at a specified dose and against a specified comparator, establishes the same benefit in children with a different disease.
Circle one: True False
A protocol recruits adults who depend on a clinic for care. Recruiters omit material risks and say usual care will be withdrawn if they decline. What should the review committee do?
- Approve because clinic dependence makes follow-up efficient.
- Approve because a novel endpoint removes the need to disclose material risks.
- Withhold approval until consent and safeguards are repaired.

Answer key

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What a trial result is allowed to claim W1-mt_xKBKzSYxLh-s1

It reduces selection bias in allocating trial treatments. · Random assignment reduces treatment-selection bias and balances factors on average. Concealment prevents recruiters from steering enrollment. Chance imbalances can remain.
Early safety, tolerability and dosing · Phase 1 studies early safety, tolerability and dosing in a small group. It does not establish safety or benefit for every future patient.
True · Blinding can reduce effects of treatment knowledge on care, reporting and assessment. It does not remove every source of bias.
A marker effect, not proven clinical benefit. · The result supports an effect on the marker. Without clinical outcomes or evidence validating the surrogate in this setting, it alone does not establish patient benefit.
0.5 · Treatment risk is 6 / 100 = 0.06. Control risk is 12 / 100 = 0.12. Relative risk is 0.06 / 0.12 = 0.5.
Check target biology, exposure, patient selection and trial design. · Several causes could explain the result. It does not by itself establish target failure, and safety findings do not establish efficacy.
False · The result concerns the studied population, disease, dose and comparator. Its phase label does not establish the same benefit in another population and disease.
Withhold approval until consent and safeguards are repaired. · Omitting material risks prevents an informed decision. Threatening loss of usual care undermines voluntary participation. Scientific interest excuses neither defect.