Temporal patterns of Veteran suicide: Variation by season, day of the week, and holidays

To assess temporal patterns of Veteran suicide deaths from 2001 to 2021. Data from Veterans Affairs (VA) and Department of Defense (DoD) administrative sources and the VA/DoD Mortality Data Repository identified 133,867 Veteran suicides from 2001 to 2021. Incidence Rate Ratios (IRRs) and Joinpoint regression assessed patterns of Veteran suicide across seasons, days of the week, and 14 holidays; overall and by sex and age. Incidence of Veteran suicide was highest in summers and on Mondays. Veteran suicide incidence was lower on six holidays: Martin Luther King Jr. Day (IRR = 0.82, 95% CI = 0.73-0.93), Presidents' Day (IRR = 0.88, 0.78, 0.99), Memorial Day (IRR = 0.89, CI = 0.79-0.99), Labor Day (IRR = 0.88, CI = 0.78-0.98), Thanksgiving (IRR = 0.81, CI = 0.71-0.92), and Christmas (IRR = 0.78, CI = 0.68-0.89). Suicide incidence was elevated on New Year's Day (IRR = 1.17, CI = 1.05-1.31), particularly among Veterans 25-34 years old (IRR = 1.64, CI = 1.19-2.26). An increasing trend in daily average suicides was indicated from December 30th to January 1st (β = 1.79, p