RESUMEN
We investigate the efficacy of a multisectoral road safety campaign initiated at Luang Namtha Provincial Hospital (LNPH), North-Laos. Road safety days (RSD) with helmet promotion were organised prior to the Lao and International New Year 2007. Motorbike helmet protectiveness was demonstrated by dropping peeled versus unpeeled coconuts from 6-m high sticks simulating city speed-limit (40 km/h). The primary outcome was the number of road traffic injuries (RTI) needing admission (severe RTI) before and after the first RSD. Secondary outcomes were helmet usage, total RTI, hospital staff's behavioural changes and law enforcement. Neighbouring Bokeo Provincial Hospital (BPH) had no intervention. Severe RTI dropped by 34.7% within 12 months (from 449 to 293, p ≤ 0.0001, BPH +123% [from 88 to 196]). Total RTI increased by 10.8% (from 772 to 855, p = 0.0396, BPH +260.8% [from 186 to 671]). Police started the law enforcement right after the RSD. Helmet use increased from 11.2 to 42.5% (p < 0.0001). Coconut test was the main reason for safer behaviour among RSD participants seven months later (16/32). The intervention effectively prevented severe RTI. The speed-adapted coconut drop test was a simple, convincing and efficient educational tool, easily adaptable to other settings.