Predictors of overdose response hotline use for mental health and fatal overdose prevention.

Objectives: The overdose crisis remains one of the largest public health issues facing North America to date. Formalized virtual spotting services have gained popularity as a harm reduction intervention, proving early effectiveness in reducing overdose mortality. This study determined the characteristics of individuals who recurrently use one such service, Canada's National Overdose Response Service (NORS).

Methods: In this retrospective study, call logs from NORS were analyzed from service inception. Demographics including age, gender, province, community size, substance used, routes of administration, and adverse events were all collected and imputed into a marginal means and rates model to determine the predictors of recurrent service use.

Results: A total of 7340 unique calls were included within our analysis. Of those, 1167 (15.8%) reported their gender as male, 3744 (51.0%) as female, and 1329 (18.1%) as gender diverse, and 1100 (14.9%) did not report their gender. In terms of age, 46 (0.6%) were individuals under the age of 18 years, 3561 (48.5%) were between 18 and 30, 557 (7.6%) were between 31 and 40, 2505 (34.1%) were between 41 and 50, 525 (7.1%) were age 51 or over, and 146 (2.0%) did not report their age. Men's rate ratios for recurrent calls were significantly lower than women's (RR = 0.08, 95% CI = 0.07‒0.09), as were those for respondents aged 31‒40 years as compared with those aged 18‒30 (RR = 0.26, 95% CI = 0.15‒0.45). Between regions, rate ratios for callers from British Columbia (RR = 0.28, 95% CI = 0.17‒2.24) and Atlantic provinces (RR = 0.09; 95% CI = 0.07‒0.12) were significantly lower than those for callers from the province of Ontario. Similarly, rural callers demonstrated lower recurrent service use (RR = 0.08; 95% CI = 0.07‒0.11) than their urban counterparts.

Conclusion: NORS demonstrates higher usage patterns within certain demographic groups, in particular, urban women. The results can therefore be used to target public health messaging toward those who derive the most benefit from the service and to tailor programming to those who are at highest risk to use alone.