An examination of factors associated with tobacco smoking amongst patients presenting with deliberate self-poisoning

Objective: To explore the relationship between tobacco use with mental health diagnoses and alcohol dependency in a sample of overdose admissions. Method: This study was a secondary analysis of an existing health service database. Prospectively collected data from 1997-2013 of 7,133 patients over the age of 18 years admitted to the Hunter Area Toxicology Service (HATS) for deliberate self-poisonings was investigated. A structured preformatted data collection form was used on admission by HATS to prospectively capture information on patient demographics (age, sex, postcode), drugs ingested (including doses), use of drugs of abuse, regular medications and management and complications of poisoning. Of the existing data within the HATS database, the current study included: tobacco smoking status, psychiatric illness, substance use, repeat admission, sociodemographic variables (age, sex, marital status) and ethnicity. The data was analysed utilising a multiple logistic regression model. Results: Within a deliberate self-harm population, those diagnosed with: an amphetamine substance use disorder (OR = 1.84, CI = 1.41, 2.41, p <.001), alcohol use disorder (OR = 1.68, CI = 1.49, 1.88, p < .001), other substance use disorder (OR = 1.77, CI = 1.38, 2.28, p < .001), psychotic diagnoses (OR = 1.17, CI = 1.01, 1.35, p = .032), or had a history of self-harm (OR = 1.15, CI = 1.03, 1.28, p =.011) were more likely to be a current tobacco smoker. Those who were older (OR = 0.99, CI, 0.986, 0.994, p < .001) or diagnosed with a mood disorder (OR = 0.87, CI = 0.78, 0.98, p = 0.018) were less likely to smoke tobacco. Conclusions: Our study found that among a deliberate self-poisoning population those who were younger, diagnosed with a variety of substance use disorders, or had a history of previous self-harm were more likely to use tobacco. Unexpectedly those with a mood disorder were less likely to smoke tobacco. Further research is required to understand the underlying mechanisms between the association between tobacco smoking and suicide and self-harm.