Background Acute drug poisonings are increasing year by year and have become the leading cause of acute poisoning in Shanghai in recent years, and the related prevention and control work is faced with a tough situation.

Objective To understand the composition of drugs leading to acute poisonings and describe the epidemiological tendency of reported acute drug poisonings in Shanghai.

Methods We collected registered acute drug poisoning case information from the Shanghai Health Information System under Shanghai Health Statistics Center, including demographic characteristics and clinical diagnosis. There were totally 86476 cases reported from 2019 to 2021. The distributions of drugs and victims were described by year. Incidence tendency of acute drug poisonings was analyzed by chi-square test and the analysis focused on analgesic, hypnotics, and antidepressant drug-associated poisonings. Spatial autocorrelation analysis was performed by GeoDa1.20 through calculating global and local Moran's I.

Results There was an ascendant tendency in both case count (22132 cases in 2019, 29071 cases in 2020, and 35273 cases in 2021) and crude morbidity (0.89‰ in 2019, 1.21‰ in 2020, and 1.46‰ in 2021) of patients who received outpatient service or emergency treatment for acute drug poisonings from 2019 to 2021 in Shanghai. The top 3 kinds of acute poisoning drugs were analgesics, hypnotics, and antidepressants. The morbidity rates of acute drug poisonings associated with antidepressants (χ²=2700.15, P<0.05) and analgesics (χ²=2294.01, P<0.05) increased year by year. The leading 3 kinds of drugs associated with acute drug poisonings in the same age group were similar. Analgesics showed high frequency staying in the top 3 acute poisoning drugs in most age groups for the 3 years (the highest morbidity was 0.84‰ in male or 1.07‰ in female). Antidepressants were in the top 3 acute poisoning drugs in the under 59 years age groups for the 3 years (male morbidity rate was 0.12‰-0.44‰, and female morbidity rate was 0.06‰-0.45‰). Hypnotics were in the top 3 acute poisoning drugs in the ≥ 18 years age groups for the 3 years (morbidity rate in male was 0.28‰-0.98‰, and morbidity rate in female was 0.21‰-0.92‰). Cardiovascular drugs were in the top 3 acute poisoning drugs in the > 60 years age group for the 3 years (male morbidity rate was 0.40‰-1.03‰, and female morbidity rate was 0.66‰-0.81‰). Regarding the causes of poisonings, accidental poisoning and exposure was the main cause in the ≤ 17 years groups (male constituent ratio was 57.64%-67.12%, and female constituent ratio was 55.27%-68.27%); suicide (male constituent ratio was 20.28%-43.51%, and female constituent ratio was 25.18%-52.02%) had a higher percentage than accidental poisoning and exposure (male constituent ratio was 16.97%-23.62%, and female constituent ratio was 12.76%-17.63%) in the 18-59 years age groups; accidental poisoning and exposure (male constituent ratio was 24.38%-45.18%, and female constituent ratio was 32.69%-38.11%) had a higher percentage than suicide (male constituent ratio was 12.35%-14.02%, and female constituent ratio was 11.92%-12.31%) in the > 60 years age group. The spatial autocorrelation analysis showed that the distribution of acute poisoning cases caused by analgesics, hypnotics, or antidepressants was not random. It was mostly positive spatial clustering. The high-morbidity area was always in the outer-ring circle, especially in Xuhui, Changning, and Jing'an districts, which suggested a high-high cluster pattern.

Conclusion In view of the increasing morbidity rate of acute drug poisoning cases in Shanghai in this study, it is urgent to take prevention and control actions. We should plan further studies and different strategies toward different victims with distinct drug poisoning characteristics and areas with high morbidity rates.