Can propensity score matching replace randomized controlled trials?

Table 1 Comparison of randomization methods for clinical trials

Method	Description	Ref.
Simple randomization	Each participant has an equal chance of being assigned to any of the treatment groups. This method is easy to implement and unpredictable, but it may result in unequal group sizes or imbalances in important covariates, especially in small studies	Grimm and Müller[75], 1999
Block randomization	Participants are allocated to treatment groups in blocks of fixed size, such as 4 or 6. This method ensures that the group sizes are balanced at any point of the study, but it may introduce some predictability if the block size is known or guessed by the investigators	Sreedevi et al[76], 2017
Stratified randomization	Participants are first stratified by one or more relevant factors, such as age, gender, or disease severity, and then randomized within each stratum. This method ensures that the treatment groups are balanced with respect to the stratification factors, but it may increase the complexity and cost of the randomization process	Kahan and Morris[21], 2012
Minimization	Participants are allocated to the treatment group that minimizes the imbalance in a set of predefined factors, such as prognostic variables or previous treatments. This method is adaptive and can achieve better balance than stratified randomization, but it may also introduce some predictability and bias if the allocation is not concealed	Treasure and MacRae[77], 1998