Major Physical Health Conditions and Risk of Suicide

Introduction

Most individuals make healthcare visits before suicide, but many do not have a diagnosed mental health condition. This study seeks to investigate suicide risk among patients with a range of physical health conditions in a U.S. general population sample and whether risk persists after adjustment for mental health and substance use diagnoses.

Methods

This study included 2,674 individuals who died by suicide between 2000 and 2013 along with 267,400 controls matched on year and location in a case–control study conducted in 2016 across eight Mental Health Research Network healthcare systems. A total of 19 physical health conditions were identified using diagnostic codes within the healthcare systems’ Virtual Data Warehouse, including electronic health record and insurance claims data, during the year before index date.

Results

Seventeen physical health conditions were associated with increased suicide risk after adjustment for age and sex (p<0.001); nine associations persisted after additional adjustment for mental health and substance use diagnoses. Three conditions had a more than twofold increased suicide risk: traumatic brain injury (AOR=8.80, p<0.001); sleep disorders; and HIV/AIDS. Multimorbidity was present in 38% of cases versus 15.5% of controls, and represented nearly a twofold increased risk for suicide.

Conclusions

Although several individual conditions, for example, traumatic brain injury, were associated with high risk of suicide, nearly all physical health conditions increased suicide risk, even after adjustment for potential confounders. In addition, having multiple physical health conditions increased suicide risk substantially. These data support suicide prevention based on the overall burden of physical health.

Introduction

In April 2016, the Centers for Disease Control and Prevention released a report documenting a 24% rise in the U.S. national suicide rate between 1999 and 2014.¹ The U.S. suicide rate, now reaching 13 per 100,000, is at its highest mark in 30 years. Importantly, suicide rates increased for both male and female individuals as well as across all age groups from 10 to 74 years.¹ National data indicate that from 2005 to 2012 the age-adjusted mortality rates declined for each of the top ten causes of death in the U.S., except for suicide.2, 3 Taken together, these findings place a national spotlight on the urgent need to develop, disseminate, and implement more-effective suicide prevention practices.³

The 2012 National Strategy for Suicide Prevention has provided an evidence-informed roadmap, including a series of aspirational goals and objectives, to reduce suicide in the U.S.⁴ Specifically, Aspirational Goals 8 and 9 promote all healthcare settings as one of the most promising and critical environments to implement suicide prevention practices.⁵ This is consistent with data showing that more than 80% of individuals make a healthcare visit in the year before suicide, and nearly 50% have a visit within 4 weeks of their death.⁶

In healthcare settings, patients receive services delivered by clinical providers, who have the opportunity to detect suicide risk and intervene. To date, health systems have generally targeted suicide prevention and intervention for patients with known risk focusing primarily on individuals with mental health and substance use conditions or those with expressed suicidal ideation.7, 8 Supporting this approach are studies based on psychological autopsy reports indicating that 90% of individuals who die by suicide may meet criteria for a psychiatric condition.⁹ Although several interventions have reduced suicide rates in these targeted behavioral health patient populations,10, 11, 12, 13 these efforts have not made a measureable difference in reducing the overall population suicide rate.

A major reason for the limited impact of these targeted interventions is that most individuals do not have a diagnosed mental health condition, nor do they receive behavioral health specialty care. National findings estimate that among people who die by suicide, only 45% have a mental health or substance use diagnosis in the prior year; furthermore, only 14% have a mental health–related inpatient hospital stay and 29% receive specialty behavioral health outpatient treatment.⁶ These data suggest that either (1) mental health conditions are largely unidentified in medical settings; (2) mental health symptoms often do not present until very near the time of suicide; or (3) many patients do not actually have a mental health condition before suicide. More importantly, these data argue that suicide prevention targeted only to patients in behavioral health settings will necessarily miss the majority of individuals at risk for suicide, which is why identification in general medical settings is so vital. Nonetheless, the U.S. Preventive Services Task Force recently determined that evidence was insufficient to inform recommendations on suicide screening and prevention in primary care settings.¹⁴

Research from several countries outside the U.S. as well as from the U.S. military and veteran populations suggests that many physical health conditions may increase suicide risk. These studies show that chronic pain, heart disease, chronic obstructive pulmonary disease, stroke, cancer, congestive heart failure, and asthma have all been associated with increased risk for suicide.15, 16, 17, 18, 19 Research also suggests that having multiple physical health conditions may be linked with even greater risk for suicide.¹⁶ It is unclear whether the association between physical health conditions and suicide is restricted to only a small set of specific conditions or whether most conditions increase risk. Risk data could be used to identify individuals for targeted prevention in general medical settings. However, similar analyses have not been available for the U.S. general population, which has a vastly different healthcare system and culture than other countries or the military. The current study seeks to examine major physical health conditions as risk factors for suicide, while also adjusting for mental health or substance use diagnoses, in a large case–control study within eight U.S. healthcare systems. The investigation includes a series of both common and rare diagnoses that may be associated with suicide risk, and have been investigated in these other populations.