How much of a difference can palliative care make in the lives of terminally ill patients? Can the intervention actually lead to reduced rates of suicide in certain at-risk populations? Those are questions Donald Sullivan, MD, and his team sought to answer with their investigation into the role of palliative care in the treatment of US military veterans with advanced lung cancer.1Dr Sullivan is assistant professor of pulmonary and critical care medicine, the Oregon Health & Science University (OSHU) School of Medicine and Knight Cancer Institute, and core investigator at the Center to Improve Veteran Involvement in Care at the Veterans Affairs (VA) Portland Health Care System.
The circumstances amount to a perfect storm: Suicide is a leading cause of death in this country on its own; suicide rates are higher among people with cancer, particularly lung cancer; and veterans are significantly more likely to take their own life than other Americans. Other mitigating factors also contribute to higher suicide rates among veterans with lung cancer. Advanced cancer accompanied by a high symptom burden and low physical function increases this risk. Depression, often a comorbidity, further exacerbates the risk for suicide among these patients.
A Place for Palliative Care
Because palliative care can improve many risk factors for untoward events, Dr Sullivan and his team sought to determine if veterans with advanced lung cancer would benefit from the intervention. For their analysis, the investigators reviewed the data from approximately 20,900 veterans in the VA Central Cancer Registry who had advanced lung cancer (stages IIIB and IV) between January 2007 and December 2013.1
Patients were determined to have committed suicide if the cause of death was listed as ICD-9-CM E950.x (suicide and self-inflicted injuries) or ICD-10-CM X60-X84 (intentional self-harm). Exclusion criteria included if the cause of death was listed as unknown (less than 1% of cases). Although 88% of patients with lung cancer died from their disease, suicide was listed as the cause of death in 30 patients. Firearms was the method used in most of the suicide cases, and median time from cancer diagnosis to death by suicide was 91 days.
“We found a suicide rate almost 6 times higher among patients with advanced stage lung cancer who did not receive palliative care compared with a matched sample from the general veteran population who did. Palliative care was associated with a significant reduction in this risk: reducing the odds by approximately 80%,” Dr Sullivan explained in an interview with Oncology Nurse Advisor.
Because suicide is a relatively rare event, its incidence is often reported per 100,000 person years. In the United States, the suicide rate is approximately 13 per 100,000 person years, and among veterans who use VA health care, it is approximately 35 per 100,000 person years. The incidence in our cohort —30 events among approximately 21,000 patients —was approximately 210 per 100,000 person years, which represented a 579% increase compared with the age, sex, and year of death adjusted rate among veterans who use VA health care. This incidence rate varies somewhat from year to year and represents data from a national health system with more than 9 million enrollees over 7 years (DR Sullivan, electronic communication, September 2018).