Suicide deaths and nonfatal hospital admissions for deliberate self-harm in the United States: Temporality by day of week and month of year

Background: No one knows whether the temporality of nonfatal deliberate self-harm in the United States mirrors the temporality of suicide deaths. Aims: To analyze day- and month-specific variation in population rates for suicide fatalities and, separately, for hospital admissions for nonfatal deliberate self-harm. Methods: For 12 states, we extracted vital statistics data on all suicides (n = 11,429) and hospital discharge data on all nonfatal deliberate self-harm admissions (n = 60,870) occurring in 1997. We used multinomial logistic regression to analyze the significance of day-to-day and month-to-month variations in the occurrence of suicides and nonfatal deliberate self-harm admissions. Results: Both fatal and nonfatal events had a 6%–10% excess occurrence on Monday and Tuesday and were 5%–13% less likely to occur on Saturdays (p < .05). Males were more likely than females to act on Wednesdays and Saturdays. Nonfatal admission rates were 6% above the average in April and May (p < .05). In contrast, suicide rates were 6% above the average in February and March and 8% below it in November (p < .05). Conclusions: Suicides and nonfatal hospital admissions for deliberate self-harm have peaks and troughs on the same days in the United States. In contrast, the monthly patterns for these fatal and nonfatal events are not congruent.