Carabin 1997 CAN.

Methods	Cluster‐RCT Allocation sequence: day‐care centres were stratified by incidence of respiratory infections and block randomized by geographical areas Allocation concealment: unclear Blinding: none Inclusion of participants in the analysis: unclear Length of follow‐up: 6 months Cluster‐adjustment method: adjusted
Participants	Number: 52 day‐care centres, with 1729 children Inclusion criteria: presence of at least 1 sandbox and 1 play area; at least 12 available toddler places Exclusion criteria: not stated Age: 18 months to 3 years
Interventions	Intervention (see Table 5 for detailed description): Large group hygiene training (educators) Handouts Control: No intervention
Outcomes	Diarrhoea rates
Notes	Location: Quebec, Canada Duration: September 1996 to November 1997
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Computer generated‐ block randomized.
Allocation concealment (selection bias)	Unclear risk	Not described.
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	Not described.
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Not described.
Incomplete outcome data (attrition bias) All outcomes	Low risk	43 children lost to follow‐up (5 day care centres excluded from the analysis).
Selective reporting (reporting bias)	Low risk	None observed.
Other bias	Low risk	None observed.