A Double Blinded Study is the gold standard of clinical trials to ensure a new drug or treatment is effective. Cancer.gov defines it as “A type of clinical trial in which neither the participants nor the researcher knows which treatment or intervention participants are receiving until the clinical trial is over. This makes results of the study less likely to be biased. This means that the results are less likely to be affected by factors that are not related to the treatment or intervention being tested.” The use of an inert placebo is vital in these studies to accurately assess the safety of the treatment or drug.
Let us create a very basic example of a test. Pretend we are a drug company that has a new drug we want to test for adverse side effects and in particular: cancer. 2,000 people are enlisted for a Double Blinded Study. 1,000 people are given the drug, and 1,000 people are given a placebo (no drug). By monitoring the effects of the group over 1 year we can collect all adverse events that happen within that given time frame. At the end of our fake study we take our data and see that 20 people have developed cancer. When we look at the group we discover 19 of the 20 people (95%) are in the group that took our drug. We can state with a very high degree of certainty that our drug causes cancer as an adverse side effect. If however the result was split down the middle 10 and 10 we could say that because the group not given our drug developed the same amount of instances of cancer we can say that it is unlikely that cancer is a side effect of our drug.
What if we were unethical? What if we invested a lot of money into this drug and wanted to minimize liability for adverse long term side effects? One way we could cover ourselves is by unblinding the study. We could give the 1,000 people in the placebo group the actual drug a few months into the study. This way when 20 people develop cancer there is no way to know if the cancer was caused by the drug or not. We have successfully manipulated the data to our benefit to mathematically get rid of any unwanted long term side effects that could be tied to us after we give the drug to the public. When the public asks why we did this we could state “It would be unethical to not give our life saving drug to these poor people in the placebo group.” Do you think this is a problem? Do you think Drug companies could do this and get away with it? Actually…. Yes.. they have and they do. Far more often than you should be comfortable with. Any grade school science student learns that any scientific experiment must have a control. Yet here is a short list of clinical trials where no placebo group was present. Links to the published papers of the trials included.
The Hep B Vaccine “Urban youth, ages 12 to 17 years, at participating Adolescent Medicine Trials Network for HIV/AIDS Interventions Clinical/Research sites were randomized to receive either 2 doses of Recombivax HB (10 microg hepatitis B surface antigen) or Twinrix (20 microg hepatitis B surface antigen and 720 EL.U hepatitis A antigen) at 0 and 24 weeks.”
Rotavirus Vaccine in 3-5 month old Children “To assess the safety and immunogenicity of bovine rotavirus vaccine, we administered attenuated strain RIT 4237 to 54 inner-city infants randomized to one of three groups in a double-blind fashion to receive a dose at 3 and 5 months of age of either placebo, vaccine virus at 10(7) TCID50/ml, or vaccine virus at 10(8) TCID50/ml.”
- This is a tricky one because they use the phrase “a double-blind fashion” it makes you believe that indeed they gave a placebo right? Actually what they did was give a lower dose of the vaccine to what they refer to as the “placebo” group… But BOTH groups of “inner-city infants” received the Vaccine.
Chicken Pox Vaccine “Subjects with a negative history of varicella were randomized to receive either one or two injections of the vaccine given 3 months apart.”
Pneumococcal Vaccine “118 young children 18 to 30 months of age received a single immunization with one of the three glycoconjugates or with licensed pneumococcal vaccine.”