The long-term rollout of basic life support (BLS) instruction in secondary schools faces numerous obstacles. It remains uncertain whether school teachers who receive instructor training can deliver BLS education that is no more than 20% inferior (noninferiority margin) to that provided by healthcare professionals when assessing simulated BLS performance among secondary school students. A two-arm, parallel, blinded, noninferiority randomized controlled study was undertaken in four secondary schools in Hong Kong after teachers completed BLS instructor preparation. Students were assigned to either a trained-teacher group or a healthcare-instructor group for a 2-hour compression-only CPR plus automated external defibrillator (CO-CPRAED) session. Evaluators who assessed BLS performance six months after the course remained blinded to group allocation. Among the 33 teachers who received training, 13 (39.4%) agreed to instruct the CO-CPRAED classes. A total of 311 students (median age 15 years; 67% male) were randomized to the teacher-led arm (n = 161) or the healthcare-led arm (n = 150). At the six-month follow-up, both groups demonstrated high passing rates for BLS skill performance (teacher: 88% vs. healthcare: 91%; mean difference −3%, 95% CI −11% to 5%; P = 0.22). Knowledge retention stayed high (>90%) in each group and showed no significant difference between them (P = 0.91). Teachers expressed mildly favorable attitudes toward future BLS instruction, whereas students showed extremely strong enthusiasm for learning and carrying out BLS. A short 2-hour CO-CPRAED lesson delivered by trained teachers was noninferior to instruction by healthcare professionals and was linked to highly positive student attitudes, as well as strong retention of BLS knowledge and practical skills.
