Table 2.

Methodological quality of the trials meeting the inclusion criteria

	Hall [20]	Rossum [8]	Dalby [21]	Stuck [15]	Haastregt [23]	Yamada [22]	Hout [19]	Bouman [12]
Descriptive items
1 Were eligibility criteria clearly specified	+	+	+	+	+	+	+	+
2 Were index and control interventions explicitly described	+	+	+	+	+	+	+	+
3 Was there a description of whether adverse effect had or had not occurred	-	+	+	+	+	+	+	+
4 Was a short-term follow-up measurement (directly after the intervention) performed	+	+	+	-	+	+	+	+
5 Was a long-term follow-up measurement (6+ months after the intervention) performed	-	-	-	+	+	-	-	+
Statistical items
6 Was the sample size for each group described	+	+	+	+	+	+	+	+
7 Were point estimates and measures of variability presented	-	+	+	+	+	+	+	+
Validity items
8 Was treatment allocation concealed	+	+	+	+	+	?	+	+
9 Were groups similar at baseline regarding age, sex, outcome	-	+	-	-	+	+	+	+
10 Were co-interventions avoided or comparable	?	?	?	?	?	?	?	?
11 Was compliance acceptable in all groups	?	+	?	?	+	+	?	+
12 Was the outcome assessor blinded to the intervention	+	+	+	+	+	+	+	+
13 Was the withdrawal/dropout rate acceptable (max of 20% for short-term follow-up and 30% for long-term follow-up)	-	+	+	+	+	+	-	+
14 Was timing of the outcome assessment in both groups comparable	+	+	+	+	+	+	+	+
15 Did the analysis include an intention-to-treat analysis	?	+	+	+	+	+	+	+
Sum score validity items
+	3	7	5	5	7	6	5	7
?	3	1	2	2	1	2	2	1
-	2	0	1	1	0	0	1	0

Notes: scores +, criterion fulfilled; -, criterion not fulfilled; ?, data not provided or unclear (The results of the study by van Hout et al. have not been published yet; questions 3, 7, 9 and 13 were assessed from unpublished information; questions 10 and 11 could not be assessed.)