DiGuiseppi 2002.

Methods	RCT (C) Allocation at level of electoral wards
Participants	Households in council rented accommodation
Interventions	I = free smoke alarm, and offer of free fitting, reminder to change batteries C = no smoke alarm
Outcomes	Outcomes measured at 18 months: Fire related injuries: Rate ratio (RR) 1.3 (0.9,1.8), adjusted for baseline rates RR 1.3 (0.9,1.9) Hospitalisations and deaths: RR 1.3 (0.7,2.4), adjusted for baseline rates RR 1.3 (0.7,2.3) Preventable injuries*: RR 1.1 (0.8,1.7), adjusted for baseline rates RR 1.2 (0.8,1.8) Preventable hospitalisations and deaths: RR 1.0 (0.5,1.9), adjusted for baseline rates RR 1.0 (0.5,2.0) Attended fires: RR 1.0 (0.9,1.2), adjusted for baseline rates RR 1.1 (0.96,1.3) *Preventable = independently judged by 2 researchers blinded to treatment arm to be potentially preventable had a working smoke alarm been present. Functional smoke alarms
Notes	Blinding ‐ y Outcomes 80% ‐ y(i) n(sp) Balance ‐ n/a
Risk of bias
Bias	Authors' judgement	Support for judgement
Allocation concealment (selection bias)	Low risk	Adequate