Background Poisoning is the leading cause of injury death and the second leading cause for injury-related hospitalization in British Columbia (B.C). Recent estimates show that unintentional poisoning (including misuse, abuse, or overdose of prescription and illicit drugs) is responsible for 84% of total poisoning costs in B.C. While previous research has demonstrated inequities in poisoning-related emergency department visits and hospital admission rates across social and material deprivation spectrums, the specific deprivation profile of the most vulnerable groups has not been previously described.

Objective To demonstrate the socio-demographic profile and involved substances in serious home-based unintentional poisonings in B.C. and to determine the hospitalization rates across neighbourhood deprivation quintiles.

Methods British Columbians who were hospitalized for unintentional poisoning at home from 2015 to 2019 were eligible for inclusion in this study, using the variables sex, age-group, substances involved, and the dissemination area of the place of residence. Using de-identified administrative data, we used the Canadian Index of Multiple Deprivation to categorize marginalization of the area of residence into quintiles (with quintile 5 representing the most deprived areas) across four dimensions of residential instability, economic dependency, ethno-cultural composition, and situational vulnerability.

Results A total of 4,559 British Columbians were admitted for unintentional poisoning occurring at home across the study period, of whom 50.5% were male (annual rate: 18.51 per 100,000). Some 13.3% were under 19 years of age, 31.3% were 19–44, 28.7% were 45–64 and 26.7% were 65 years of age or older. The most common involved substances were narcotics and hallucinogens (32.9%) followed by anti-epileptic and sedative-hypnotic drugs (24.4%). The highest hospitalization rates were observed for quintile 5 of situational vulnerability composition (33.44 per 100,000), followed by quintile 5 of economic dependency (28.7) and residential instability (27.39).

Conclusions The rate of serious unintentional poisoning was highest for quintile 5 of situational vulnerability, which reflects the most deprived areas regarding housing and education. Equity-oriented approaches are essential to decrease the observed gap between the least and the most deprived populations, by reducing differential exposures, vulnerability and consequences of unintentional poisoning among marginalized populations.