I will start this paper by discussing the “why” of randomization, as a preface to explaining the “how”. My focus will be on practicalities and I will therefore not include mention of trials of oral or injected agents, where randomization is typically conducted by a pharmaceutical company, with blinded medication sent to the pharmacy at each study site. In this didactic paper, I will outline the basics for effective randomization and reporting thereof. reported that just 16% of randomized trials adequately report an appropriate randomization procedure( 1). This is not a problem specific to integrative oncology: in one systematic review, Pildal et al. In my experience, it is rare indeed that a trial I review either as grant applications or as submitted papers includes an adequate description of randomization in sufficient detail. Given the importance and prevalence of randomized trials, it is a continual surprise to me how little most researchers understand about their distinguishing feature: randomization. Computer randomization can easily incorporate extensions of randomization, such as blocking, stratification and minimization, that can help ensure balance between groups. Randomization should be conducted either by a pharmaceutical company, which sends blinded medication to the hospital pharmacy, or by a secure, password protected database system. The use of telephone randomization, and opaque envelopes have been suggested as good randomization method, but both can be subverted. The purpose of randomization is to prevent selection bias: randomization procedures must therefore ensure that researchers are unable to predict the group to which a patient will be randomized until the patient is unambiguously registered on study moreover, researchers must be unable to change a patient’s allocation, after they are registered. Many investigators do not pay sufficient attention to randomization procedures and several studies have shown that only a fraction of trial reports describe randomization adequately.
Randomized trials are an important method for deciding whether integrative oncology therapies do more good than harm.
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