Lee 2012.

Methods	A cohort study of methylphenidate use in children with ADHD for 4 weeks
Participants	Number of participants screened: not stated Number of participants included: 93 Number of participants followed up: 63 Number of withdrawals: 30 Diagnosis of ADHD: DSM‐IV‐TR (subtype: combined (84.1%), hyperactive‐impulsive (not stated), inattentive (not stated)) Age: mean 8.58 (SD 1.61) years IQ: mean 96.39 (SD 17.01) Sex: 56 males, 7 females Methylphenidate‐naïve: not stated Ethnicity: not stated Country: Korea Comorbidity: not stated Comedication: not stated Sociodemographics: not stated Inclusion criteria 6‐12 year old elementary school children with a diagnosis of ADHD recruited from 3 university hospitals Children whose ADHD accompanied by anxiety disorder, oppositional defiant disorder, or conduct disorder were included in the study Exclusion criteria Patients with tic disorder, Tourette syndrome, schizophrenia, bipolar disorder, major depressive disorder, obsessive‐compulsive disorder or a pervasive development disorder An IQ below 70, epilepsy or other neurological problems Those who had been taking stimulants, antidepressants, antipsychotics, atomoxetine, clonidine, and antihistamine within 4 weeks of baseline Sleep problems such as heavy snoring, sleep apnoea, sleep bruxism, narcolepsy, restless legs syndrome, and periodic limb movement disorder Participants were dropped from the study if they violated the study protocol by failing to take the prescribed medicine more than twice a week, or if they presented with serious adverse effects such as seizures or hallucinations
Interventions	Methylphenidate type: osmotic release oral system (OROS) or Metadate‐CD Mean methylphenidate dosage: 1.0 (SD 0.25) mg/kg. Initial doses for OROS‐MPH 18 mg and Metadate‐CD 10 mg; dose range and maximum dose for OROS‐MPH was 0.4‐1.8 mg/kg and 72 mg and for Metadate‐CD was 0.6‐1.5 mg/kg and 60 mg) Administration schedule: daily Duration of intervention: 4 weeks Treatment compliance: the children and caregivers were visited weekly to review whether medication was taken as prescribed
Outcomes	Non‐serious adverse events Daily sleep diaries were completed by caregivers (parents/guardians) at baseline and for 4 weeks after taking medication Adverse events (AEs) chart was completed weekly on the basis of direct questions, clinical observations and physical examinations by child psychiatrist
Notes	Sample calculation: irrelevant Ethics approval: the study protocols were reviewed and approved by each site's Institutional Review Board Funding/vested interests: Yeungnam University research grants in 2009. No conflicts of interest statement Key conclusions of the study authors: methylphenidate had negative impacts on sleep among young ADHD children, but different preparations and doses did not affect the result Comments from the study authors: data yielded by a sleep diary, which relies on the validity of parents' observations, may not be an accurate representation of reality. Used a flexible titration method and did not divide the participants into parallel groups from the beginning. Lack of blinding. More than 30% did not complete the procedure. Comments from the review authors: participants were dropped from the study if they violated the study protocol by failing to take the prescribed medicine more than twice a week, or if they presented with serious adverse effects such as seizures or hallucinations Exclusion of methylphenidate non‐responders/children who have previously experienced adverse events on methylphenidate: not stated Supplemental information requested from the study authors in August 2014. Email sent twice but no answer received