Table 3.

Methodologic quality* scores of the included studies

Study	Similarity of baseline characteristics?	Cointerventions avoided or similar?	Compliance acceptable in all groups?	Timing of the outcome assessments similar?	Score maximum	Study score	Percentage
Gerdesmeyer et al. [9]	?	+	+	+	12	9	75
Albert et al. [1]	+	+	+	−	12	9	75
Pleiner et al. [21]	+	+	+	+	12	8	67
Rompe et al. [22]	+	−	+	+	12	5	42
Loew et al. [17]	?	?	+	+	12	4	33

* = quality criteria of Furlan et al. [8]; + = yes = 1 point; − = no = 0 points; ? unclear/unsure = 0 points; high-quality = greater than 50%;

low-quality = less than 50%.