Soleimani 2017.

Study characteristics
Methods	A 4‐week cross‐over‐trial with 4 arms: 1 week of MPH 0.25 mg/kg/d 1 week of MPH 0.5 mg/kg/d 1 week of MPH 1 mg/kg/d 1 week of placebo Phases: 3 phases (4‐week cross‐over with focus on ADHD symptoms followed by 1‐week washout period and 2‐week cross‐over with focus on DCD symptoms)
Participants	Number of participants screened: 28 Number of participants included: 17 (12 boys, 5 girls) Number of participants followed‐up: 16 Number of withdrawals: 1 Diagnosis of ADHD: DSM‐IV TR (100% combined type) Age: 7 years 6 months (± 18 months) (range 6‐11 years or 6‐12 years) IQ: 96.6 (± 12.5, range 80‐118) MPH‐naive: history of MPH usage, mean 22.9 days (range 0‑90 days) Ethnicity: not stated Country: Iran Setting: outpatient Comorbidity: all participants had DCD. No other comorbidities allowed Comedication: not stated Additional sociodemographics: number of siblings: 1.3 (SD 0.5, range 1‐2) Inclusion criteria 6‐11 years old (between 6 and 12 years) (Article and registry) Diagnosis of ADHD and DCD based on the diagnostic interview according to DSM‐IV‐TR criteria Recently diagnosed case (< 3 months), or no prior experience with stimulant medication Exclusion criteria Associated psychiatric disorders (pervasive developmental disorders, anxiety, conduct, mood disorders and schizophrenia) Evidence of a specific learning or neurological disorder (neurologic problems, seizures, cerebral palsy, sensory deficits including vision and hearing) or IQ score < 70 on Raven's intelligence test Occurrence of side effects, poor compliance/irregular drug consumption (present in registry, not in article)
Interventions	Participants were randomly assigned to 1 of 4 possible orders of 3 different doses (0.25, 0.5 or 1 mg/kg/d) of MPH (Ritalin) and placebo for 1 week each Number randomised to each group: not stated Mean medication dosage: not applicable (mean minimal effective dose per day was 17.3 mg (mean 0.85 mg/kg, ± 0.16)) Administration schedule: twice/d, 8:00 and 15:00 Duration (of (each) medication): 3 weeks of MPH with 3 different doses, 1 week of placebo Washout before trial initiation: no Medication‐free period between interventions: no Treatment compliance: not stated
Outcomes	ADHD symptoms ADHD‐RS‐IV Results were only reported for the MPH intervention and no data have been included in our analysis
Notes	Sample calculation: yes. “The sample size was estimated from the previous double‐blind study. We estimated that the recruitment of 13 cases would provide 90% power to detect a significant difference between the effects of treatment on motor performance at a significance of P<0.05.” Ethics approval: yes Comments from trial authors "Although the MTA study found that 77 percent of children responded to MPH, we had no non‐responder in this study. It is possible that this result is due to the small sample size of the study." "The present study is the first crossover clinical trial regarding the impact of MPH on ADHD/DCD." "It should be noted that the usage of minimal effective dosage instead of a fixed MPH dosage as well as the crossover study design are the novelties of this study compared with previous investigations." Key conclusion of trial authors "The present study demonstrated that there was a significant association between ADHD symptoms and motor performance. Overall, MPH improves motor performance only in 26.6% of the children. In addition, this study revealed that the change in BOT‐2 [the Bruininks‐Oseretsky Test of Motor Proficiency Second Edition] score between the 2 periods was not significantly different (period effect) and the improvement to motor performance in our population was not different to with/without MPH. There is the possibility that this finding is due to a relatively short period (one week) of MPH intervention. Therefore, we recommend a replication of this study with a larger sample size and higher dosage of MPH." Exclusion of MPH non‐responders/children who have previously experienced AEs while taking MPH: no Any withdrawals due to AEs: no Funding source: Guilan University of Medical Sciences Email correspondence with trial authors: August, October and November 2021. We contacted the trial authors for information regarding age of participants and first‐period data through personal email in August, October and November 2021, but no answer was received.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	The patients were randomly allocated into one of the 4 groups using a random number generator.
Allocation concealment (selection bias)	Low risk	Quote: "The key to the randomization was kept by the pharmacy and randomization was broken only in case of potential adverse events." Comment: no adverse events stated, and no statement of code breaking.
Blinding of participants and personnel (performance bias) All outcomes	Low risk	These drugs were prepared by the Shafa Hospital Pharmacy and placed into similar gelatinous capsules. Drugs were labelled by trial participant number according to the randomisation schedule. Parents and the researchers were blinded to child’s drug condition and dosage.
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Parents and the researchers were blinded to child’s drug condition and dosage.
Incomplete outcome data (attrition bias) All outcomes	Low risk	Only 1 withdrawal Selection bias (e.g. titration after randomisation → exclusion of MPH non‐responders or placebo responders): no
Selective reporting (reporting bias)	Low risk	All outcomes from protocol reported