Efficacy and safety of botulinum toxin type A in distraction osteogenesis of the lower extremities: a meta-analysis of randomized controlled trials

Table 3 Risk of bias assessed by Jadad scale

	Hamdy et al., 2009 [2]	Lee et al., 2014 [15]	Hamdy et al., 2016 [16]	Park et al., 2016 [17]
Described as randomized^a	1	1	1	1
Described as double blinded^a	1	1	1	1
Description of withdrawals^a	1	1	1	1
Randomization method described and appropriate^b	1	1	1	0
Double-blinding method described and appropriate^b	1	1	1	1
Score	5	5	5	4

^aA study scores 1 for “yes” and 0 for “no”
^bA study scores 0 if no description is given, 1 if the method is both described and appropriate, and − 1 if the method is described but inappropriate

ISSN: 1471-2474