2.3. Blinding
BLIND
Vials containing melatonin and placebo were numbered 1 and 2, not necessarily in that order. The person responsible for assigning the numbers was the only person with knowledge of which vials contained melatonin and which contained the placebo. This person did not participate in any other phase of the study. All the other people involved in this project (patients, medical researchers, statisticians and assistants) were blind to the substances contained in each vial. Upon completion of the statistical analysis, the researchers were informed which vial contained melatonin and which contained the placebo. The melatonin and placebo capsules were manipulated in the artisanal pharmacy in Belo Horizonte, production batch 0630/0122. The melatonin was imported from wuxi cim science, China, batch CS-MEL-210615. The placebo was composed of Aerosil + starch + micronized cellulose + talc. The capsules, both for the placebo (bottle 2) and the melatonin (bottle 1), were identical in terms of color (white), smell (odorless) and shape, making it impossible to distinguish which capsule was melatonin and which was the placebo. The vials were also identical except for the numbering.