Ziegler 1971.

Methods	Randomised, parallel group, chemotherapeutic trial, single‐site trial (Uganda). ITT: unclear. Withdrawals: not stated.
Participants	Baseline characteristics: sample size; 20 evaluated for study, main study apparently focused on an initial 15. Age range: 3 to 14 years. Tumour staging: Ziegler. Diagnosis: unclear. Entry criteria: BL at stages I to III; no evidence of malignant pleocytosis on admission. Exclusion criteria: not stated.
Interventions	Prophylactic IT versus no treatment. Treatment duration: 4 or 10 days. Follow‐up: participants followed to relapse.
Outcomes	Relapse rate
Notes	Full publication. The study describes a sequential trial of different drug regimens following relapse in the same set of participants. Induction of remission was by a randomised schedule though outcomes were not described. Study type: remittance maintenance.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Participants were said to be "randomly allocated".
Allocation concealment (selection bias)	Unclear risk	Not described in the text.
Blinding (performance bias and detection bias) All outcomes	Unclear risk	Method of blinding but it was unlikely that blinding was done.
Incomplete outcome data (attrition bias) All outcomes	Low risk	Relapse rates were described for outcomes and were reported for all participants who relapsed.