Miller‐Horn 2008.

Methods	A retrospective cohort study of patients with ADHD attending a clinic over a 2‐year period taking methylphenidate
Participants	Number of participants screened: 516 Number of participants included: 150 Number of participants followed up: 137 Number of withdrawals:13 63 took MPH, of which 40 (29.2% of whole sample) took extended release methylphenidate and 23 (16.8%) took immediate release methylphenidate. Diagnosis of ADHD: DSM‐IV (subtype: combined 121 (88.3%), hyperactive‐impulsive 4 (2.9%), inattentive 12 (8.8%)) Age: males: mean 9.9 (SD 3), range 4‐19 years old; females: 10.9 (SD 3.4), range 4‐17 years old IQ: not stated Sex: 109 males, 28 females Methylphenidate‐naïve: 65% Ethnicity: not stated Country: USA Comorbidity: 87 (64%) (type: oppositional defiant disorder/conduct disorder (16%), seizures (15%), learning disabilities (14%), PDD 13%, sleep disturbances (9%), mental retardation/cerebral palsy (7%), chronic headaches (6%), Tourette's (6%), obsessive compulsive disorder/depression (6%)) Comedication: all patients were on monotherapy for medications used in the treatment of ADHD; however, some of the patients were currently being treated for comorbid conditions Sociodemographics: not stated Inclusion criteria DSM‐IV diagnosis of ADHD Taking anti‐ADHD medication including any form of dexamphetamine, any form of methylphenidate, atomoxetine Exclusion criteria Treatment with any other medication including clonidine, Focalin, Metadate, guanfacine Patients diagnosed and/or treated by a clinician "outside our group"
Interventions	Methylphenidate type: osmotic release oral system (OROS) and immediate release OROS‐methylphenidate dosage: mean 34.2 (SD 13.6) mg/day (range 18‐54) IR‐methylphenidate dosage: mean 23.3 (SD 14.8) mg/day (range 5‐60) Administration schedule: not stated Duration of intervention: not stated Treatment compliance: not stated
Outcomes	Retrospective database analysis. The database contained information on side effects. No other information regarding measurement available
Notes	Sample calculation: not stated Ethics approval: approved by the Institutional Review Board at St. Christopher's Hospital for Children in Philadelphia Funding/vested interests/authors' affiliations: not stated Key conclusions of the study authors: atomoxetine showed a significantly lower incidence of headaches than amphetamine/dextroamphetamine XR, amphetamine/dextroamphetamine or OROS‐methylphenidate Exclusion of methylphenidate non‐responders/children who have previously experienced adverse events on methylphenidate: not stated Supplemental information requested twice in June 2014 with no reply