Medical illness, medication use and suicide in seniors: a population-based case–control study

Background:Suicide among seniors is a significant health problem in north America, particularly for men in whom the rates rise steadily after 50 years of age. The goal of this study was to examine elder suicides identified from a large population-based database using case–control methods to determine disease and medication factors related to suicide.Methods:A population-based 1 : 5 case–control study was conducted comparing seniors aged 66 years and older who had died by suicide with age and sex-matched controls. Case data were obtained through British Columbia (BC) Vital Statistics, whereas controls were randomly selected from the BC Health Insurance Registry. Cases and controls were linked to the provincial PharmaCare database to determine medication use and the provincial Physician Claims and Inpatient Hospitalization databases to determine co-morbidity.Results:Between 1993 and 2002 a total of 602 seniors died by suicide in BC giving an annual rate of 13.2 per 100 000. Firearms were the most common mechanism (28%), followed by hanging/suffocation (25%), self-poisoning (21%), and jumping from height (7%). In the adjusted logistic model, variables related to suicide included: lower socioeconomic status, depression/psychosis, neurosis, stroke, cancer, liver disease, parasuicide, benzodiazepine use, narcotic pain killer use and diuretic use. There was an elevated risk for those prescribed inappropriate benzodiazepines and for those using strong narcotic pain killers.Conclusion:This study is consistent with previous studies that have identified a relationship between medical or psychiatric co-morbidity and suicide in seniors. In addition, new and potentially useful information confirms that certain types and dosages of benzodiazepines are harmful to seniors and their use should be avoided.