Practical aspects of randomization and blinding in randomized clinical trials.

Randomization and blinding are important tools in determining the effectiveness of a new intervention and ensuring the validity of a clinical trial. However, randomness and haphazardness are not equivalent. Randomization cannot overcome poor experimental design or technique. Several types of randomization including historical controls and pseudorandomization are discussed, as well as methods of treatment allocation, stratification, and minimization techniques. The importance of decreasing bias and the advantages and disadvantages of blinding in randomized clinical trials are also covered.