Enhancing identification of suspected unregulated drug toxicity deaths in administrative health records: a case study among people with HIV in British Columbia, Canada
摘要
Accurate and timely cause of death information is important for public health monitoring. In recent years, deaths with an unknown/ill-defined underlying cause have increased markedly in Canada, particularly in British Columbia (BC), among people living with HIV (PWH) in concert with the 2016 unregulated drug toxicity crisis. Using a case study of PWH in BC, who are disproportionately affected, we examined all deaths occurring between 2015 – 2020 and adapted a published method to classify unknown-cause deaths as likely drug-related.
MethodsFrom the STOP HIV/AIDS cohort (a linkage of administrative healthcare and clinical data for PWH in BC), we categorized all deaths in the cohort between 2015 – 2020 into three cause of death groupings: unknown-cause (ICD-10 coded “R99”), drug- related (X41-X42; X44; Y11-Y12; Y14), and non-drug related causes (all other deaths). We described and compared decedents’ demographics, residence and clinical characteristics including lifetime drug use history and drug-related healthcare contact occurring 12 and 24 months preceding death. We estimated the percentage of unknown-cause deaths that met the following criteria for likely drug-related death classification: a) aged 20–64 at death, b) a “pending”, “accident”, or “undetermined” manner of death; and c) a history of unregulated drug use (drug-related healthcare contact or clinical data).
ResultsOf 849 deaths among PWH in BC between 2015 – 2020, 79 were unknown-cause (9%), 155 drug-related (18%), and 615 non-drug-related (72%). The unknown-cause deaths closely resembled confirmed drug-related deaths regarding several sociodemographic characteristics (sex, age, residence, location of death) and drug-related healthcare contact in the 12 months preceding death (75% of unknown-cause and 72% of drug-related deaths, respectively). Applying the classification criteria, 86% of unknown-cause deaths were classified as likely drug-related, increasing the estimated number of drug-related deaths from 155 to 223 (by 44%).
ConclusionsOur findings indicate many deaths of unknown cause among PWH in BC between 2015 – 2020 were likely drug-related, suggesting an underestimation of the true burden of the unregulated drug toxicity crisis in this population based on standard mortality records. This approach may be further examined in non-PWH cohorts and validated using updated mortality data.