Inappropriate prescription drug use and suicide in seniors

Purpose The aim of this study was to assess a possible relationship between suicide in seniors and the inappropriate prescription of medication. Methods A population-based 1:5 case-control study was conducted comparing seniors aged 65 years and older who had committed suicide to age and gender matched controls. Inappropriate medications were determined using Beerʹs Explicit Criteria (Beers, 1997) for inappropriate drugs for seniors. Case data were obtained through British Columbia (BC) Vital Statistics while controls were randomly selected from the BC Health Insurance Registry. Cases and controls were then linked to the provincial Pharmacare database to determine medication use and the provincial Physician Claims database to determine comorbidity. Comorbid conditions were aggregated over a 1-year period prior to the suicide, while current medication use was quantified in the 30 days prior to the event. Inappropriate prescriptions were aggregated over a 1-year period prior to the suicide. Stepwise logistic regression was used to determine independent comorbidity and medication use variables related to suicide. Results Between 1996 and 1999 a total of 308 seniors were coded as committing suicide in BC giving an annual rate of 15.6/100,000. The mean age of suicides was 76.2 years and 71.1% were male. The use of a firearm was the most common mechanism (29%) followed by hanging (26%) poisoning (19%), and jumping (9%). In the logistic model, variables related to suicide included: mental health diagnosis (OR = 2.86; 95% CI: 2.11, 3.87), cancer diagnosis (OR = 1.86; 95% CI: 1.31, 2.65), injury diagnosis (OR = 1.48; 95% CI: 1.12, 1.96), antidepressant use (OR = 2.77; 95% CI: 1.72, 4.45), sedative/hypnotic use (OR = 3.33; 95% CI: 2.23, 4.75), antibiotic use (OR = 1.99; 95% CI: 1.27, 3.13) and inappropriate sedative use (OR = 2.06; 95% CI: 1.24, 3.42). Conclusion This study suggests that the inappropriate use of sedative class drugs may be related to suicide when other medication use and health conditions are accounted for.