7. Random sequence generation
Selection bias (biased allocation to interventions) due to inadequate generation of a randomized sequence. If they say only "randomized" this says nothing about the random sequence generation (select Unclear and enter "NR"). There is a low risk of selection bias if the investigators describe a random component in the sequence generation process such as: referring to a random number table, using a computer random number generator, coin tossing, shuffling cards or envelopes, throwing dice, drawing of lots, minimization (minimization may be implemented without a random element, and this is considered to be equivalent to being random). There is a high risk of selection bias if the investigators describe a non-random component in the sequence generation process, such as: sequence generated by odd or even date of birth, date (or day) of admission, hospital or clinic record number; or allocation by judgement of the clinician, preference of the participant, results of a laboratory test or a series of tests, or availability of the intervention. ADD NOTE IF UNCLEAR (usually "NR") OR HIGH ROB.