Table 2. Characteristics of ADHD youths prescribed IR–MPH, OROS–MPH, or ATX during the study period.
| Characteristics | IR-MPH (N = 69110) | OROS-MPH (N = 35922) | ATX (N = 5283) |
|---|---|---|---|
| Sex | |||
| Female | 12644 (18.3) | 6027 (16.8) | 798 (15.1) |
| Male | 56646 (81.7) | 29895 (83.2) | 4485 (84.9) |
| Age at diagnosis of ADHD (years) | 8.2 ± 3.0 | 8.3 ± 3.0 | 7.4 ± 2.8 |
| Psychiatric comorbidity | |||
| ODD or conduct disorder | 8396 (12.1) | 5676 (15.8) | 1012 (19.2) |
| Autistic spectrum disorder | 7123 (10.3) | 3860 (10.7) | 948 (17.9) |
| Tic disorder | 4622 (6.7) | 2823 (7.9) | 1004 (19.0) |
| Intellectual disability | 10519 (15.2) | 4941 (13.8) | 849 (16.1) |
| Anxiety disorders | 22181 (32.1) | 12697 (35.3) | 2305 (43.6) |
| Depressive disorders | 4232 (6.1) | 2383 (6.6) | 480 (9.1) |
| Initiation of treatment | |||
| Age at first prescription (years) | 9.0 ± 2.8 | 10.3 ± 2.7 | 10.9 ± 2.9 |
| Days between ADHD diagnosis and first prescription | 286.5 ± 549.7 | 760.3 ± 800.6 | 1289.7 ± 919.7 |
| Median (range) | 21 (0–4178) | 492 (0–4310) | 1137 (0–4279) |
| Prescribed within 30 days | 38447 (55.6) | 5525 (15.4) | 222 (4.2) |
| Prescribed within 180 days | 49567 (71.7) | 12595 (35.1) | 555 (10.5) |
| Prescribed within 1 year | 53066 (76.8) | 16114 (44.9) | 925 (17.5) |
| Prescribed within 2 years | 58527 (84.7) | 21300 (59.3) | 1692 (32.0) |
| Persistence of treatment during follow-up | |||
| Age at the last prescription (years) | 10.6 ± 3.1 | 12.0 ± 3.0 | 11.4 ± 2.9 |
| Days between first prescription and discontinuation | 539.3 ± 714.9 | 444.2 ± 507.7 | 150.7 ± 176.6 |
| Median (range) | 193 (1–4183) | 234 (1–2495) | 73 (2–848) |
| Only received prescription once | 12304 (17.8) | 4530 (12.6) | 991 (18.8) |
| Discontinued within 180 days | 29173 (42.2) | 10680 (29.7) | 2519 (47.7) |
| Discontinued within 1 year | 35271 (51.0) | 13959 (38.9) | 3106 (58.8) |
| Discontinued within 2 years | 42562 (61.6) | 18021 (50.2) | 3518 (66.6) |
| Average daily dose (mg) | 15.1 ± 8.3 | 26.1 ± 8.9 | 30.3 ± 11.4 |
Note: Data are expressed as mean ± SD or n (%); the three patient groups were not independent samples; 33674 (93.7%) of the patients receiving OROS–MPH treatment were prescribed IR–MPH previously; 4954 (93.8%) of the patients receiving ATX treatment were prescribed IR–MPH or OROS–MPH previously.