Speculation: Randomized Controlled Trials for wonder drugs and Vitamin D have very different participations
Participation varies with
1) How much the person is paid,
2) The cost/availability of the drug
3) The belief that it will help
0 % belief | 100 % belief | |
Wonder drug | often paid to participate | 50% chance of getting the wonder drug which is typically very expensive or unavailable |
Vitamin D | rarely paid to participate | If skip trial then have 100% chance of getting Vitamin D Can also increase the dose if high risk, etc Can also adjust co-factors Can also change the type of vitamin D if not getting benefit Vitamin D is low cost and very available |