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Abstract
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Introduction
Late life is often associated with declining health, with an estimated 11-32% of community-dwelling older adults living with frailty. Frailty, a durable phenotype associated with depression, is often measured as an accumulation of physical and mental deficits. This underlying distress may be associated with suicidal thoughts. Frailty has never been assessed as a risk factor for suicide on a national level but may be useful as a prognostic marker. Our primary objective was to determine the relationship of frailty to subsequent risk of suicide attempt and death by suicide across age groups in a large national cohort of veterans aged 50+. With >70% of the veteran population aged 50+ and ∼70% of veteran suicides occurring in older veterans, this study has potential to be highly impactful.
Methods
We performed a longitudinal cohort study on a national sample of mid to late-life veterans: All veterans aged 50+ who used VA healthcare services during study baseline of fiscal years 2012-2013 (N=5,059,526) with ongoing follow-up through the end of calendar year 2017. We linked four national databases: (1) National Patient Care Database (NPCD), for VA inpatient and outpatient services; (2) Centers for Medicare & Medicaid Services (CMS), for non-VA inpatient and outpatient services; (3) Suicide Prevention Applications Network (SPAN), for information on non-fatal suicide attempts; and (4) Mortality Data Repository (MDR), for cause-specific death information and dates. Demographic information for age, gender, and race/ethnicity was obtained from NPCD and/or CMS records. To study the role of frailty and its connection to late-life suicide-related behaviors, we used a cumulative deficit method and frailty index (FI) developed by Orkaby et al. (2019). This index integrates 31 variables (deficits) from ICD-9/10 diagnoses and procedure codes and HCPCS (Healthcare Common Procedure Coding System) codes from NPCD and CMS data. Variables relate to morbidity (e.g., diabetes), functional status (e.g., use of durable medical equipment), cognition and mood (e.g., depression), sensory loss (e.g., blindness), and other geriatric conditions (e.g., weight loss in the past year). FI scores were calculated at baseline index date of study entry and within two years prior, summing the number of accrued deficits then dividing by 31 (total number of possible deficits), producing scores from 0 to 1. We defined Non-frail as FI≤0.1, Pre-frail as 0.10.4. Suicide attempt and death outcomes were derived from SPAN and MDR databases through 2017. Non-fatal suicide attempts were derived from SPAN, based on standardized clinician reports uploaded to the national database. Fatal suicide attempts were derived from MDR with ICD-10 codes X60-X84 and Y87.0. Cumulative incidence of any suicide attempt was plotted by patient age in years across frailty categories. We used Cox proportional hazards regression to examine time to suicide attempt at follow up, with age as the time scale and censoring at end of study. We examined multivariable models adjusted in steps: Model 1, unadjusted; Model 2, adjusted for demographics (race, gender, region); Model 3, Model 2 + adjusted for substance use disorder and PTSD; Model 4, Model 3 + adjusted for Charlson Comorbidity Index (CCI). We did not adjust for depression as it was included in the FI. We adjusted for CCI to examine the FI's robustness as a marker for suicide risk in the context of another global index.
Results
Our sample's average age was 68 (SD 11), 94% male, 77% white, and 14% black. Fifty-one percent of veterans aged 50+ were non-frail, while 26% were pre-frail, 12% mildly frail, 6% moderately frail, and 4% severely frail. The average FI score was 0.10. There were 29,679 suicide attempts at follow up, with 9,659 fatal attempts. Cumulative incidence rates of suicide attempt were significantly higher for more frail than less frail individuals (Figure 1). Our fully adjusted model (Table 1, Model 4) showed a strong dose-response relationship between frailty severity and risk of suicide attempt (fatal and non-fatal), with hazard ratios (HR) increasing from 1.55 for Pre-frail to 2.50 for Severely frail individuals. An attenuated HR effect was seen for fatal attempts: ranging from 1.29 for Pre-frail to 1.56 for Severely frail individuals. Furthermore, we found a significant interaction of FI by age groups 50-64 and 65+ (p-interaction<0.001) with higher HRs and a more salient dose-effect in ages 50-64.
Conclusions
Our findings suggest a cumulative deficit FI may be a strong prognostic marker associated with risk of suicide attempt in young-old to oldest-old beyond other factors such as substance use disorder, PTSD, and CCI. This study provides clinicians with a better understanding of potential frailty-related suicide risk in patients aged 50+.
Funding
I01 CX001119-05 (PI: Byers) Veterans Administration Clinical Science Research & Development
Language: en |