Corkum 2008.

Study characteristics
Methods	3‐week, blind medication trial with cross‐over design, in which children were randomly assigned to the following: LD‐MDH; MD‐MDH placebo
Participants	Number of participants included: 28 Number of participants followed‐up: 21 (15 boys, 6 girls) Number of withdrawals: 7 children excluded from final data analyses Diagnosis of ADHD: DSM‐IV (combined type (52%), hyperactive‐impulsive type (10%), inattentive type (38%)) Age: mean not reported (range 6 years 1 month‐12 years 1 month) IQ: no intellectual disability MPH‐naive: 100% Setting: outpatient clinic Country: Canada Ethnicity: all participants were white Comorbidity: learning disabilities (29%), ODD (10%), CD (0%), generalised anxiety disorder (0%), depression (0%) Comedication: not stated Other sociodemographics: predominantly middle‐class families Inclusion criteria Stimulant medication‐naive DSM‐IV criteria for 1 of the 3 ADHD subtypes Received a recommendation to initiate a trial of MPH following assessment Parents/caregivers agreed to initiate a stimulant medication trial through the clinic paediatrician Exclusion criteria IQ < 1 SD below the mean on the WISC‐IV Known neurological, metabolic or seizure disorder Currently taking other psychotropic medications or medications for sleep disturbances Symptoms of an intrinsic sleep disorder (i.e. sleep apnoea, restless legs syndrome or periodic limb movements in sleep) or a sleep‐onset disorder based on parent report Reached criteria for another mental health disorder that was considered primary to the ADHD diagnosis (e.g. autism)
Interventions	Participants were randomly assigned to 1 of 3 medication‐dosing schedules, including 1 week of baseline, placebo and low and moderate IR‐MPH (Ritalin) dose condition Children weighing ≤ 25 kg received 5‐mg and 10‐mg doses; children weighing > 25 kg received 10‐mg and 15‐mg doses. Children received medication 3 times/d (8:00 am, 12:00 pm, 4:00 pm) Duration of medication: 1 week of each dose Treatment compliance: not stated
Outcomes	ADHD symptoms CPRS, CTRS ‐ Revised, Short Form: rated weekly Non‐serious AEs Sleep Disturbances Scale for Children based on child’s sleep over previous week: rated by parents Actigraphy Sleep diary
Notes	Sample calculation: not stated Ethics approval: yes Key conclusion of trial authors "Based on findings from the current trial, we would encourage physicians and parents to closely monitor children’s sleep when treating ADHD with stimulant medication, and to carefully weigh the benefits of improved behavioural functioning while taking medication against the potential negative consequences of sleep" Comment from review authors Paper includes data on AEs: sleep disturbance (ActiGraph data, sleep diary data, Sleep Disturbances Scale for Children data) related to MPH treatment compared with placebo Exclusion of MPH non‐responders/children who have previously experienced AEs while taking MPH before randomisation: no Any withdrawals due to AEs: no Funding source: research was supported by a grant from the Izaak Walton Killam IWK Health Centre in Halifax, Nova Scotia Email correspondence with trial authors: August‐October 2013. We received supplemental information regarding additional data from trial authors, but we never received first‐period data from the cross‐over trial.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Baseline data from 1 week were collected, followed by a 3‐week medication trial with random assignment of children to 1 of 3 medication‐dosing schedules. The original, fully randomised schedule was modified after a pilot trial, conducted before the current trial, indicated that children receiving MD‐MPH before the LD‐MPH reported increased side effects and were more likely to stop taking the third dose (4:00 pm) of medication
Allocation concealment (selection bias)	Low risk	Pharmacy local to the ADHD clinic prepared both placebo and active medication, which were packaged into identical gelatin capsules
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Child, family, school personnel and trial investigators were unaware of the randomisation schedule. This information was made available only to the paediatrician and the pharmacist
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Child, family, school personnel and trial investigators were unaware of the randomisation schedule. This information was made available only to the paediatrician and the pharmacist
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	7 children excluded from final data analyses for the following reasons: actigraphic problems (i.e. data failure/loss of ActiGraph/refusal to wear ActiGraph) (n = 5), withdrawal of consent due to marital discord (n = 1) and decision to try alternative medication immediately before the start of the medication trial (n = 1) Selection bias (e.g. titration after randomisation → exclusion of MPH non‐responders or placebo responders): no
Selective reporting (reporting bias)	Low risk	Protocol received through correspondence with trial author. No indication of selective reporting.