ba Cochran 2010b

Methods	see ba Cochran 2010a
Participants
Interventions
Outcomes
Funding Source
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
CC‐Case Selection	High risk	Not clearly described
CC‐Control Selection	Unclear risk	Apparently same population
CC‐Comparability	High risk	Insufficient description
CC‐Exposure	Unclear risk	Secure record
Summary assessments	High risk	Lack of information about study design and matching method