Petridou 1997.

Methods	CBA (C) Allocation at level of islands
Participants	Population of two Greek islands, Naxos (intervention) and Spetses (Control)
Interventions	I = community intervention including safety seminars for parents, workshops with teachers promoting school safety, courses with primary and secondary school children on safety and resuscitation, leaflets; plus focused intense intervention: lay home visitors, weekly visits to discuss home safety in households with children ( <=18 years) or older people ( >=65 years) C = none of the above
Outcomes	Outcomes measured over 20 months: Possession of a fire extinguisher Poison centre number accessible Possession of ipecac Slip resistant bathroom mat Has a fire escape plan Safe balconies I = 24/128, C = 36/131, OR 0.61 (0.34 to 1.10) Safe indoor stairs I = 104/128, C = 110/131, OR 0.83 (0.43 to 1.58) Safe outdoor stairs I = 32/128, C = 17/131, OR 2.24 (1.17 to 4.27) Has circuit breaker ‐ Significant increase in the use of circuit breakers in intervention group from baseline. No difference in circuit breakers between intervention and control group I = 115/128, C = 120/131, OR 0.81 (0.35 to 1.88). Score comprising 28 home safety practices ‐ Mean (SD) score I = 15.18 (2.62), C = 15.24 (2.17)
Notes	Blinding ‐ n Outcomes 80% ‐ y Balance ‐ y
Risk of bias
Bias	Authors' judgement	Support for judgement
Allocation concealment (selection bias)	Unclear risk	Not applicable ‐ non‐randomised study