Associations of Medical Outcomes with Substances Involved in Suicide Attempt Cases Age 50 and Older Reported to U.S. Poison Centers, 2016-2023

Namkee G. Choi ^1* Bryan Y Choi ² C Nathan Marti ¹ S David Baker ³

• ¹ The University of Texas at Austin, Austin, United States
• ² Philadelphia College of Osteopathic Medicine (PCOM), Philadelphia, Pennsylvania, United States
• ³ Central Texas Poison Center, Temple, TX, United States

Background and aims: After a slight decline in suicide rates during the COVID-19 pandemic, suicide rates and suicide attempts in the U.S. have been increasing again in 2022 and 2023. Compared to younger age groups, the 50+ age group has significantly higher rates of serious medical outcomes from suicide attempts. In this study, we examined the medical outcome severities associated with different classes of substances involved in suicide attempt cases age 50 and older who were reported to poison centers.Methods: We used the America's Poison Center's National Poison Data System from 2016 to 2023 (N=335,171 cases age > 50). Following descriptive statistics on the characteristics of suicide attempters and involved substances by medical outcomes (no/minimal effects, moderate effects, major effects, death, and unable to follow), we fitted multinomial and binary logistic regression models to examine the associations of medical outcomes with involved substances.Results: Of all cases, 22.5% used antidepressants, 21.1% benzodiazepines,16.4% cardiovascular drugs, and 12.5% prescription opioids; 44.1% had no/minimal effect, 37.9% had a moderate effect, 12.5% had a major effect, 1.2% resulted in death, and 4.4% were unable to follow, but the proportions of major effects and death were higher in 2022-2023 than in 2016-2017. Tricyclic antidepressants were associated with the highest risks of major effects (relative risk ratios [RRR]=5.57, 95% CI=5.26-5.90) and death (RRR=4.26, 95% CI=3.67-4.94). Large RRRs were also shown for bupropion and serotonin-norepinephrine reuptake inhibitors for major outcomes and death. Cardiovascular drugs, opioids, and muscle relaxants were also associated with consistently higher risks of moderate and major effects and death. Our results also show that older ages were associated with higher death rates and that female sex was associated with higher odds of moderate/major effects compared to minimal effects but lower odds of major effects/death. Implications: Healthcare providers, including pharmacists, can play an important role in promoting medication safety for older adults. Healthcare workers need training in assessing and recognizing signs of suicide risk in older adults who are prescribed antidepressants and sedatives. Our findings also point to the importance of better non-pharmacological chronic pain management than reliance on opioids.