Table 3:

Association of self-harm with 5-year outcomes; propensity-matched comparisons*

OutcomeNo. (%) of adolescents with no self-harm visits
n = 10 731
No. (%) of adolescents with ≥ 1 self-harm visits
n = 5661
Time-to-event analyses HR (95% CI)RR (95% CI)Positive predictive value
Readmissions to emergency department or hospital for self-harm637 (5.9)1626 (28.7)5.52 (5.05–6.04)4.84 (4.44–5.27)28.7
Overall mortality34 (0.3)58 (1.0)3.25 (2.12–4.96)3.23 (2.12–4.93)1.0
Suicides10 (0.1)42 (0.7)8.00 (3.99–16.04)7.96 (4.00–15.86)0.7
Mean ± SDMean ± SDtp valueD
Lower-bound estimates of 5-year health care costs, $19 055 ± 53 76730 388 ± 61 31231.96< 0.0010.20N/A
  • Note: CI = confidence interval, D = group difference, HR = hazard ratio, N/A = not applicable, RR = relative risk.

  • * Hazard ratio is from the Cox proportional regression (meaning, the hazard rate for adolescents with ≥ 1 self-harm visits divided by the rate for the matched controls) for that outcome. The positive predictive value is the proportion of youths with ≥ 1 self-harm visits who have the outcome. Relative risk is the probability of the occurrence of the outcome within 5 years for adolescents with ≥ 1 self-harm visits divided by the probability of the outcome for the matched controls. t statistic is the comparison of the average log-transformed lower-bound costs, with statistical significance p.