Testing a New Drug: Controls, Placebo and the Blind Trial · seed 1 · A4, ink-friendly. The answer key prints on its own page for grown-ups.

Testing drugs without fooling yourself

Science · Scientific Inquiry · ages 15-16
Name ______________________   Date ____________

  1. Why randomly assign enrolled volunteers to drug and control groups?

    • To recruit a sample that represents the wider population of patients.
    • To keep participants unaware of which treatment they receive during the trial.
    • To reduce differences created by choosing who receives each treatment.

  2. What is a placebo in a drug trial?

    • A matching tablet containing a smaller dose of the active drug being tested
    • A treatment lookalike without the active treatment being tested
    • A matching tablet containing another active drug selected to treat the condition

  3. Tests that give a candidate drug to human volunteers are classed as preclinical research.

    Circle one:   True   False

  4. Participants can tell whether their pill is drug or placebo. Both groups receive the same visits. Which problem is participant blinding intended to reduce?

    • Differences in starting health caused by how participants were assigned.
    • Differences in symptom ratings caused by researchers knowing the treatment groups.
    • Differences in reported symptoms caused by knowing which pill was received.

  5. Patients report less pain after taking a new pill. Recovery and study care could also explain improvement. Which comparison best assesses the pill's added effect?

    • Drug versus matching placebo, with assignments hidden and the same follow-up.
    • Drug users' symptoms before and after treatment, with the same follow-up visits.
    • Drug versus no tablets, with participants told which treatment they receive.

  6. Participants are blinded, but a researcher who knows assignments rates their improvement. Which change targets the remaining rating bias?

    • Keep treatment assignments hidden from the researcher rating improvement.
    • Recruit more participants while the researcher continues to see assignments.
    • Use a matching placebo while the researcher continues to see assignments.

  7. Study R compares benefits and harms in larger controlled groups. Study S examines benefit and dose in people with the condition. Study T checks for uncommon or delayed harms during wider use after approval. Which usual stage-purpose matches fit?

    • Phase 2: R; phase 3: S; monitoring after approval: T.
    • Phase 2: S; phase 3: T; monitoring after approval: R.
    • Phase 2: S; phase 3: R; monitoring after approval: T.

  8. A survey links memory-pill use with higher scores. Which follow-up design most directly addresses whether the pill affects scores?

    • Recruit more existing users and non-users, then compare their memory scores.
    • Randomly assign eligible volunteers to pill or control, then compare scores.
    • Let eligible volunteers choose pill or control, then compare their scores.
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Answer key

For grown-ups. Fold this page away before handing over the rest.

Testing drugs without fooling yourself W1-mt_If6qHIrOxT-s1

  1. To reduce differences created by choosing who receives each treatment. · Random allocation reduces selection differences between treatment groups. Recruiting a sample and hiding assignments are different design tasks.
  2. A treatment lookalike without the active treatment being tested · A placebo lacks the active treatment under study. It can contain inactive ingredients and is not a smaller active dose.
  3. False · Preclinical work precedes human trials. Phase 1 is an early human-trial stage that mainly studies safety, dose and how the body handles the drug.
  4. Differences in reported symptoms caused by knowing which pill was received. · Participant blinding targets effects of participants knowing their assignments. Allocation addresses selection differences; researcher blinding targets researchers' knowledge.
  5. Drug versus matching placebo, with assignments hidden and the same follow-up. · A blinded placebo comparison with similar care helps assess the drug's added effect. Before-and-after results include recovery, while an open no-tablet comparison can differ in expectations.
  6. Keep treatment assignments hidden from the researcher rating improvement. · Hiding assignments from the outcome rater targets bias caused by that researcher's knowledge. More participants or a matching placebo alone does not remove that knowledge.
  7. Phase 2: S; phase 3: R; monitoring after approval: T. · Phase 2 studies benefit and dose in patients, matching S. Phase 3 usually makes larger controlled comparisons of benefits and harms, matching R. Monitoring after approval matches T.
  8. Randomly assign eligible volunteers to pill or control, then compare scores. · Random assignment with a control addresses differences linked to choosing treatment. A larger observational study or self-selected groups can retain those alternative explanations.
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