The remaining six trials were at unclear risk due to inadequate descriptions of allocation concealment.
We also noted that the majority of RCT reports failed to include an adequate description of the allocation process (ie, sequence generation and allocation concealment were 'unclear').
As illustrated in Fig. 7, the description of power allocation situations are given specifically.
Individual item analysis showed substantial agreement for the description of random allocation, investigator and subject blinding, appropriateness of sample size, reporting of attrition, and reporting of statistical tests.
* Information unclear A score of 1 was given for each parameter fulfilled in the text with an additional point for adequate description of randomisation, allocation concealment and blinding.
According to the latest CONSORT statement [ 10], adequate description of random allocation sequence generation should contain at least three aspects: methods used to generate the random sequence, randomization type, and restriction details.
In general, random sequences in 8 studies [ 19, 21, 22, 24, 28, 29, 31, 32] out of 14 trials were generated correctly with clear descriptions (low risk of bias), but no trial gave a description of concealed allocation in their studies (unclear risk of bias).
Two studies were rated as being of lower quality due to unclear descriptions of randomization, allocation concealment, complete outcome data, and rate of dropout, 39 the methodology used in data analysis, the relationship of the findings to the context, and the reflexivity of the researchers.
We used a pilot tested data sheet and extracted data on drugs and diseases; types of support; sources used to identify trials for the review; searches for unpublished trials; and descriptions of concealment of allocation, details of blinding, and excluded patients and trials.
For an elaborate description of the land allocation method we refer to Hilferink and Rietveld [24] and Koomen et al. [25].
