Table 3.
Concentration of risk (CR) and conditional risk of post-hospital suicides by risk strata across all hospitalizations
| Strata of predicted suicide risk based on the lasso model2 | |||||
|---|---|---|---|---|---|
| Highest risk stratum (1st ventile) |
2nd ventile | 3rd–9th ventiles |
Lowest risk stratum (10th–20th ventiles) |
Total | |
| Observed number of suicides | 36 | 6 | 20 | 6 | 68 |
| CR1 | 52.9% | 8.8% | 4.2% | 0.9% | -- |
| n/100,000 hospitalizations | 1338.8 | 223.3 | 106.3 | 20.3 | 126.5 |
| n/100,000 person-years | 3824.1 | 538.7 | 221.1 | 40.9 | 263.9 |
| (n) | (2,689) | (2,687) | (18,820) | (29,573) | (53,769) |
Concentration of Risk (CR), which is defined as the proportion of all the observed outcomes of the type occurring in the 12 months after hospital discharge (or less than 12 months if the Soldier terminated services prior to 12 months after hospital discharge) that occurred in the risk ventile represented by the column heading. CR is defined separately for each of the two highest risk ventiles and then as a per-ventile average for the next seven ventiles treated as a single risk stratum and then final 11 ventiles treated as a separate risk stratum.
Ventiles of suicide risk = 20 groups of hospitalizations of equal frequency (n=2,688–2,689) dividing the total of 53,769 hospitalizations into groups defined by level of predicted suicide risk. The 3rd–9th ventiles were collapsed into a single risk stratum based on the fact that observed suicide risk was comparable in these seven ventiles. The 10th–20th ventiles were collapsed into a final risk stratum based on similar evidence.