Blinding and Randomization
Celery and placebo capsules were prepared similarly. They had identical
shapes, colors, sizes, textures, and odors. The capsules were packed in
the same containers with random code numbers. Hence, the participants,
researcher, physician, and data analyzer were all blinded to the
treatment and placebo groups essence. The coding of capsule containers
and randomization were performed using 6-digit numbers obtained from the
“random number table”. The first column of the random number table was
assigned to the celery-washout-placebo group and the second one to the
placebo-washout-celery group. The codes were written on a piece of paper
and put into an opaque envelope. The envelopes were sealed and placed
sequentially in a box and kept by the researcher and physician. The
envelopes and their codes were assigned sequentially to eligible
participants in order of their arrival time.