Lee 2007.

Methods	A cohort of methylphenidate use for 3 weeks plus 1 week baseline
Participants	Number of participants screened: not stated Number of participants included: 119 Number of participants followed up: 110 Number of withdrawals: 9 Diagnosis of ADHD: DSM‐IV (subtype: not stated) Age: 8.5 (SD1.6) years (range 6‐13) IQ: > 70 Sex: 107 males, 12 females Methylphenidate‐naïve: not stated Ethnicity: not stated Country: South Korea Comorbidity: oppositional behaviours (14.8%), conduct behaviours (2.3%), obsessive‐compulsive behaviours (0.8%), generalised anxiety symptoms (7.8%), depressive symptoms (12.5%), learning problems (18.8%) Comedication: not stated Sociodemographics: not stated Inclusion criteria: Full diagnosis based on DSM‐IV criteria Moderate to severe level of impairment of ADHD symptoms Drug naïve or not medicated ≥ 6 months before the initiation of the study No abnormalities in baseline physical examination and routine laboratory tests In addition only participants who were able to comply with the study visit schedule were included Exclusion criteria: Presence of clinically significant gastrointestinal problems, cardiovascular disease, glaucoma, seizure disorder, psychotic disorder, clinical depression or Tourette syndrome Suspicion or confirmation of substance abuse Receiving clonidine or other alpha‐2 adrenergic receptor agonists, tricyclic antidepressants, theophylline, coumarin or anticonvulsants IQ < 70 as determined by the Korean Wechsler Intelligence Scale for children
Interventions	Methylphenidate type: osmotic release oral sytem (OROS) Mean methylphenidate dosage: 0.87 mg/kg (SD 0.33) Administration schedule: daily Duration of intervention: 3 weeks Treatment compliance: 2 participants discontinued trial due to protocol non‐compliance
Outcomes	Non‐serious adverse events 18‐item list of stimulant related AE symptoms (compiled by authors), self‐reported, days 7, 14 and 21 Physical examination, general chemistry tests, blood pressure, pulse rate, ECG; observer, baseline and end of study 1 respondent withdrew from trial during first week of trial on 18 mg OROS because of decreased appetite of moderate severity while another participant withdrew in the same period because of insomnia of mild severity
Notes	Sample calculation: yes Ethics approval: not stated Funding/vested interests: funded by Janssen Korea Key conclusions of the study authors: these data provide support for the benefit of the once daily methylphenidate preparation Concerta, in the treatment of Korean children with ADHD. Children were initiated safely in this short‐term trial, and its effectiveness was evident in the behavioural, as well as neuropsychological measurements Exclusion of methylphenidate non‐responders/children who have previously experienced adverse events on methylphenidate: not stated