Zhang 2003.

Methods	CBA (C) Allocation at level of counties
Participants	Children aged 0‐4 years from 12 townships from 6 counties; 6 intervention and 6 control townships
Interventions	I = health education comprising booklet containing methods of preventing suffocation and drowning, education by paediatricians to prevent suffocation and teaching sessions on vaccination day C = usual care
Outcomes	Outcomes measured over 12 months: Mortality from suffocation I = 1/1414, C = 4/1447, OR 0.26 (0.03 to 2.30) Parents not swaddling babies ‐ no figures or P values reported Mortality from drowning I = 3/8293 C = 5/7653, P > 0.05, OR 0.55 (0.13 to 2.32) Use of fencing round pools ‐ No figures or P values reported
Notes	Blinding ‐ n Outcomes 80% ‐ n Balance ‐ n Intervention areas had higher baseline injury rates than control areas
Risk of bias
Bias	Authors' judgement	Support for judgement
Allocation concealment (selection bias)	Unclear risk	Not applicable ‐ non‐randomised study