Table 2. Description of the Sex-Stratified, Age-Matched Cohort for Death by Suicide or Other Causesa.
| Characteristic | Individuals, No. (%) | Standardized differenceb | Individuals, No. (%) | Standardized differenceb | ||
|---|---|---|---|---|---|---|
| Autistic females (n = 17 982) | Nonautistic females (n = 71 928) | Autistic males (n = 48 956) | Nonautistic males (n = 195 824) | |||
| Age of first autism diagnosis claim, median (IQR), y | 13 (7-30) | NA | NA | 9 (4-15) | NA | NA |
| Age at maximum follow-up, median (IQR), y | 22 (15-41) | 21 (15-40) | 0.01 | 19 (14-26) | 19 (14-25) | 0.01 |
| Follow-up duration, median (IQR), y | 11 (5-21) | 10 (5-20) | 0.04 | 9 (5-16) | 9 (4-15) | 0.03 |
| Neighborhood income quintile | ||||||
| Q1 (lowest) | 3671 (20.4) | 13 713 (19.1) | 0.03 | 9849 (20.1) | 36 145 (18.5) | 0.04 |
| Q2 | 3527 (19.6) | 13 354 (18.6) | 0.03 | 9502 (19.4) | 35 825 (18.3) | 0.03 |
| Q3 | 3416 (19.0) | 14 181 (19.7) | 0.02 | 9601 (19.6) | 39 371 (20.1) | 0.01 |
| Q4 | 3528 (19.6) | 14 786 (20.6) | 0.02 | 9876 (20.2) | 41 601 (21.2) | 0.03 |
| Q5 (highest) | 3501 (19.5) | 14 903 (20.7) | 0.03 | 9573 (19.6) | 41 422 (21.2) | 0.04 |
| Missing | 339 (1.9) | 991 (1.4) | 0.04 | 555 (1.1) | 1460 (0.7) | 0.04 |
| Rural index | ||||||
| Urban | 15 727 (87.5) | 62 028 (86.2) | 0.04 | 43 334 (88.5) | 170 708 (87.2) | 0.04 |
| Rural | 2140 (11.9) | 9628 (13.4) | 0.04 | 5285 (10.8) | 24 747 (12.6) | 0.06 |
| Missing | 115 (0.6) | 272 (0.4) | 0.04 | 337 (0.7) | 369 (0.2) | 0.08 |
| Diagnoses ever recorded | ||||||
| Intellectual disabilities | 3048 (17.0) | 238 (0.3) | 0.62 | 7595 (15.5) | 1036 (0.5) | 0.57 |
| Mood and anxiety disorders | 13 306 (74.0) | 35 576 (49.5) | 0.52 | 31 553 (64.5) | 68 774 (35.1) | 0.61 |
| Schizophrenia spectrum and other psychotic disorders | 2736 (15.2) | 1216 (1.7) | 0.5 | 6861 (14.0) | 2893 (1.5) | 0.48 |
| Substance-related and addictive disorders | 1540 (8.6) | 3597 (5.0) | 0.14 | 3630 (7.4) | 11 500 (5.9) | 0.06 |
| Personality disorders | 2276 (12.7) | 1812 (2.5) | 0.39 | 4676 (9.6) | 3635 (1.9) | 0.34 |
| Death by suicide in this 25 study-years, individuals, No. (incidence per 100 000 population) | 17 (95/100 000) | 33 (46/100 000) | 0.02 | 57 (116/100 000) | 163 (83/100 000) | 0.01 |
| Age at death by suicide, if present, median (IQR), y | 28.4 (21.0-41.3) | 26.9 (18.2-50.8) | 0.01 | 25.4 (21.0-30.8) | 26.4 (19.8-46.6) | 0.10 |
| Death by nonsuicide causes in this 25 study-years, individuals, No. (incidence per 100 000 population) | 1762 (9799/100 000) | 5836 (8114/100 000) | 0.06 | 1671 (3413/100 000) | 5073 (2591/100 000) | 0.05 |
Abbreviations: NA, not applicable; Q, quintile.
a
Accrual period from 10th birthday (or from April 1, 1993, for those older than 10 years at this date) to March 31, 2018. Most autistic individuals, across sexes, were identified via autism diagnoses recorded in outpatient and/or inpatient settings; 2.5% of autistic females (449 of 17 982) and 2.5% of autistic males (1240 of 48 956) were identified exclusively via records in emergency department visits.
b
Standardized difference of 0.1 or more implies clinical meaningfulness.37