Tzang 2012.

Methods	A prospective observational study for 48 weeks. Patients categorised into 4 groups based on occurring treatment: No treatment Immediate release (IR) methylphenidate Osmotic release oral system (OROS) methylphenidate Immediate release and osmotic release oral system methylphenidate
Participants	Number of participants screened: not stated Number of participants included: 757 Number of participants included in each group: IR methylphenidate: 265, OROS methylphenidate: 293, IR and OROS methylphenidate: 129, controls (no intervention): 70 Number of participants followed up in each arm: IR methylphenidate: 265, OROS methylphenidate: 293, IR and OROS methylphenidate: 129, controls: 70 Number of withdrawals in each arm: IR methylphenidate: 0, OROS methylphenidate: 0, IR and OROS methylphenidate: 0, controls: 0 Diagnosis of ADHD: DSM‐IV (combined (58.52%), hyperactive‐impulsive (4.76%), inattentive (36.72%)) Age: mean 10.05 (SD 2.65) years old (range: 6‐18 years) IQ: not stated Sex: 607 males, 150 females Methylphenidate‐naïve: not stated Ethnicity: white (0%), African American (0%), Asian (100%), Hispanic (0%), others (0%) Country: Taiwan Comorbidity: oppositional defiant disorder (21.80%), conduct disorder (1.85%), anxiety disorder (3.04%), depressive disorder (0.40%), tic disorder (2.64%), Tourette disorder (1.59%), somatisation (5.15%), others (7.40%) Comedication: 6.61% Sociodemographics: not stated Inclusion criteria: Age 6‐18 years ADHD according to DSM‐IV No ADHD medication for ≥ 4 weeks Living with parents/caregivers who could complete questionnaires during the study Ability of parents or guardians to provide signed and dated informed consent for the participations of their children/wards in the study Being still at school Exclusion criteria: Parents/caregivers with known or suspected psychotic disease, mental retardation or any mental condition that may affect their ability to complete the questionnaires Glaucoma or seizures Parents/caregivers with drug or alcohol abuse/dependence within the prior 6 months Serious or uncontrolled medical illness Use of one or both of the study drugs within the past month
Interventions	Methylphenidate type: immediate release (IR) and osmotic release oral system (OROS) Methylphenidate dosage: not stated Administration schedule: OROS‐methylphenidate once a day, other groups not stated Duration of intervention: 48 weeks Treatment compliance: not stated
Outcomes	The frequency of adverse effects was determined using a symptom checklist that included the following items: decreased appetite, nausea, somnolence, insomnia, headache, dizziness, abdominal pain, and stomachache at 12, 24, 36, and 48 weeks
Notes	Sample calculation: no information Ethics approval: not stated Funding/vested interests/authors' affiliations: supported by Janssen‐Cilag, Taiwan Key conclusions of the study authors: OROS methylphenidate treatment at the adequate dosage can achieve higher remission and recovery rates, produce greater functional improvement, and result in better treatment adherence that IR methylphenidate treatment Supplemental information requested through email correspondence with the authors in December 2013 and January 2014. No reply