Item	Evans 1997	Testad 2005	Huizing 2009	Pellfolk 2010	Testad 2010
METHOD
Allocation sequence adequately generated	Yes*	Yes*	Yes*	Yes*	Unclear*
Allocation adequately concealed	No*	No*	Yes*	No	Unclear*
No evidence for cluster imbalance	No	Yes	Yes	Yes	No
Clusters lost to follow‐up	0/3	0/4	1/15	0/40	0/4
Participants identified before randomisation	Yes	No*	Yes	No*	No*
If no: no evidence for biassed selection of participants	‐‐‐	Unclear	‐‐‐	Unclear	Unclear
PARTICIPANTS
Inclusion/exclusion criteria for participants clearly defined	Yes*	Yes*	Yes*	Yes*	Yes
Inclusion/exclusion criteria for clusters clearly defined	Unclear*	Yes*	Yes*	Yes*	Yes*
Sample size calculation	Yes*	No*	No*	Yes	Yes*
Adequate sample size calculation using methods for cluster randomisation	No*	No*	No*	No*	No*
No relevant differences between groups after randomisation	No	Yes	Yes	Unclear	No
Loss to follow‐up less 5% of participants	Unclear	Yes	No	Unclear	No
Were incomplete data adequately explained	Yes*	Yes*	Yes	No*	Yes
INTERVENTIONS
All groups treated equally, except of intervention or control	Yes	Yes	Yes	Yes	Yes
OUTCOMES
Primary outcome clearly stated?	Yes	Yes	Yes	Yes	Yes
Method of primary outcome assessment adequate	Yes	Yes	Yes	Yes	Yes
Outcome assessors blinded to group allocation	Yes	Yes	Yes	No	Yes
Data collection started immediately after randomisation	No*	Unclear*	No*	No*	Yes*
RESULTS
Intention‐to‐treat analysis	Yes	Yes	Yes	Yes	No*
Complete reporting of outcome (as scheduled)	Yes	Yes	Yes	Yes	Yes
Methods of analysis adequate for cluster‐randomised trials	No	No	No	Yes (partial)*	No*
Coefficient of intra‐cluster correlation reported	No	No	No	No*	No*
MISCELLANEOUS
No evidence for interpretation bias	Yes	Yes	Yes	Yes	Yes
Conflicts of interest mentioned	No	No	No	No	Yes
Requests to authors required	Yes	Yes	Yes	Yes	Yes
* Items marked with an asterisk have been answered by the study authors following personal request.