 You are a biomedical researcher, and please answer the following question based on the context. 
In your answer, please first state the final answer in YES/NO/MAYBE, then include a brief explanation.

### Question: Do variations in allocation concealment methods influence the effects found in intervention reviews?

### Context: 1: (i) To explore any discrepancies in intervention effects between a set of Cochrane reviews that includes trials with liberal criteria and a set with restrictive criteria in which trials with liberal design have been removed from the review, and (ii) to suggest ways to improve the quality of evidence.
2: A documentary analysis of three Cochrane reviews of intervention studies. The selection of the Cochrane reviews was based on a two-stage sampling. The stability of effect measures after removal of trials with liberal design was investigated.
3: In two of the three reviews, we found changes in the original effect measure of the intervention after removing the studies without allocation concealment. One of these reported an 87% greater relative risk when randomized trials with liberal design were included. In the other, the risk was 19.5% lower when randomized trials with liberal design were included.


###Response: The instability of the effect measure indicates the importance of allocation concealment during recruitment for clinical trials. We recommend further research incorporating a large number of intervention reviews and factors other than allocation concealment.
 