Table 2.

Quality assessment of included studies.

Authors
Bias	Basler et al.23	Blanchard et al.16	Blanchard et al.20	Holroyd et al.17	Holroyd et al.21	Martin et al.24	Martin et al.26	Mosley et al.18	Richardson and McGrath.25	Tobin et al.19
Random sequence generation?	U	I	U	I	U	U	U	I	U	I
Allocation concealment?	U	U	U	U	U	U	U	U	U	U
Groups similar at the outset?	A	I	A	A	A	A	A	A	A	A
Performance bias: blinding of car providers?	U	U	U	U	P	U	U	U	U	U
Performance bias: blinding of participants?	U	U	U	U	P	U	U	U	U	U
Detection bias: blinding of outcome assessors?	U	U	U	U	U	U	U	U	U	U
Unexpected imbalances in drop-outs between groups?	A	A	I	A	I	I	A	I	I	A
Free of selective reporting?	U	U	I	U	U	I	U	U	U	U
ITT analysis?	I	I	I	I	A	I	I	I	I	U
Did the analysis account for missing data?	U	I	I	P	A	I	I	I	I	U

A: adequate; I: inadequate; P: partial; U: unknown/unclear.