Overdose Risk

The zero-fatality assumption was based on NORS observations and supervised consumption site data reporting no fatalities in observed overdose events. The model assumed death probability was zero for attended overdoses. NORS was modelled as reducing fatal overdose risk by increasing witnessed overdoses and attended responses. The calibrated model estimated an 11% baseline death risk after unwitnessed overdose and a 78% baseline probability that an overdose would be witnessed without NORS. Fatality risk was modelled as highest for unwitnessed overdoses.