Table 4.

Problems identified in randomized controlled trials confirmed to be at high risk of bias and methodological adjustments with no or minor cost applied

Domains	Type of problem in original trial report	N = 121 No. (%)	Methodological adjustment	Cost
Generation of randomization sequence	Inappropriate randomization methods including sequence generated by some rule based on date/day of admission or on hospital or clinic record number	5 (4)	Referring to a random number table; Using a computer random-number generator Coin tossing Shuffling cards or envelopes Throwing dice Drawing of lots	No cost
Allocation concealment	No explicitly unconcealed procedure or unsealed or nonopaque or not sequentially numbered envelopes	10 (8)	Central allocation (including telephone, web-based and pharmacy-controlled randomization) or sequentially numbered, opaque, sealed envelopes	Minor
Incomplete outcome data	Exclusion of patients from the analysis	14 (11)	Intention-to-treat analysis	No cost
	Intention-to-treat analysis but inadequate missing data imputation	2 (1)	Intention-to-treat analysis with a multiple imputation method	Minor