One of the easiest ways to show that one drug is effective compared to another is to choose a poor comparator. This can be done in several different ways:
- compare with a low or sub-therapeutic dose to enhance the effects of the study drug
- compare with a pharmacologically poor molecule to enhance the effects of the study drug
- compare with a high dose to minimise the side effects of the study drug
- compare against a drug or dose not used in current clinical practice
When reading a study ask yourself, "Is this a valid comparison, would I have chosen to use this comparator in the study?"
For example, in the ASCOT Study the comparator arm studied doses of atenolol 100mg and bendroflumethiazide 1.25mg in Hypertension. Atenolol 100mg is no more effective than atenolol 50mg and bendroflumethiazide is used at a starting dose of 2.5mg in the UK.