A medicine is being tested to find out whether it lowers blood pressure. A pharmacist prepares identical-looking treatment packs containing either the medicine or a placebo. The pharmacist keeps a code key showing what each pack contains but does not assess the participants or analyse the results.
Participants take the tablets, and nurses measure their blood pressure.
Which statement explains how the code key should be used to make this a double-blind trial?
The pharmacist should give the code key to both the participants and the nurses before treatment begins.
The pharmacist should tell the participants what their packs contain but keep the code key from the nurses.
The pharmacist should give the code key to the nurses but not tell the participants what their packs contain.
The pharmacist should keep the code key from both the participants and the nurses until the results have been analysed.
87 exam-style questions on Edexcel GCSE Biology 5.3 Immune system and medicines, covering 5.3.1 The specific immune system, 5.3.2 Response to immunisation, 5.3.3 Advantages and disadvantages of immunisation, 5.3.4 Antibiotics and bacterial infections, 5.3.5 Aseptic techniques in culturing, 5.3.6 Cross-sectional areas of cultures, 5.3.7 Stages of developing new medicines, and 5.3.8 Production of monoclonal antibodies. Each one has a worked solution and a mark scheme showing where the marks go.