Table 2. Jadad scores for included studies.

	Study described as random ized	Study described as double blind	Description of withdrawals and dropouts	Method of randomisation was described in the paper, and appropriate.	Method of blinding described, and appropriate	Method of randomi-sation described, but inappropriate	Method of blinding describedbut inappropriate	JADADScore
Alhashemi et al. [7]	Yes	Yes	No	Yes	Yes	No	No	4
Apan et al. [8]	Yes	Yes	Yes	Yes	Yes	No	No	5
Cheung et al. [9]	Yes	Yes	Yes	Yes	Yes	No	No	5
Demiraran et al. [10]	Yes	No	Yes	Yes	No	No	No	3
Fan et al. [11]	Yes	Yes	Yes	No	No	No	No	3
Frölich et al. [5]	Yes	No	No	Yes	No	No	No	2
Frölich et al. [6]	Yes	No	No	Yes	No	No	No	2
Hashiguchi et al. [12]	Yes	No	Yes	No	No	No	No	2
Kaya et al. [13]	Yes	Yes	Yes	Yes	Yes	No	No	5
Liao et al. [14]	Yes	No	No	Yes	Yes	No	No	3
Muttu et al. [15]	Yes	No	No	No	No	No	No	1
Ustun et al. [16]	Yes	Yes	Yes	No	Yes	No	No	4