NEW YORK (Reuters Health) - Several common diseases, such as heart failure and COPD, appear to be independent risk factors for suicide in elderly patients, according to a report published in the Archives of Internal Medicine for June 14.

Although medical illness has been linked to suicide in this population, few controlled studies have looked at the association with specific diseases, lead author Dr. David N. Juurlink, from Sunnybrook and Women's College Health Sciences Centre in Toronto, and colleagues note.

To investigate, the researchers reviewed prescription records to compare the prevalence of 17 illnesses among 1329 elderly patients who committed suicide between 1992 and 2000 and 5315 living matched controls. The patients were all Ontario residents and were at least 66 years of age at the time of their deaths.

The most common cause of suicide was by firearm, accounting for 28% of all deaths. Hanging and self-poisoning were the next most common causes, responsible for 24% and 21% of all cases, respectively.

Illnesses associated with a heightened risk of suicide included heart failure, COPD, seizure disorder, urinary incontinence, anxiety disorders, depression, psychotic disorders, bipolar disorder, moderate pain, and severe pain. The increased risks ranged from 1.6-fold for COPD to 9.2-fold for bipolar disorder.

The risk of suicide was greatest when more than one of these diseases was present, the authors note. Nearly half of the suicide patients had visited a physician in the week before death.

"Physicians, nurses, and other health care professionals should be alert to the possible threat of suicide in elderly patients with chronic illness, particularly in patients with multiple illnesses, symptoms of depression, or other risk factors for suicide," the researchers point out.

In a related editorial, Dr. Eve K. Moscicki, from the National Institute of Mental Health in Bethesda, Maryland, and Dr. Eric D. Caine, from Rochester, New York, comment that "like many excellent studies, the (current one) raises more questions than it answers. (The) findings point to promising new directions and challenge us to creatively design probing new studies that will lead to novel, effective, and widely applied preventive and therapeutic interventions."

Arch Intern Med 2004;164:1171-1172,1179-1184.

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