Kotch 2003 USA.

Methods	Cluster‐RCT Allocation sequence: unclear Allocation concealment: not stated Blinding: open Inclusion of participants in the analysis: unclear Length of follow‐up: 7 months (November 2002 to May 2003) Cluster‐adjustment method: unclear
Participants	Number: 46 child‐care centres (23 intervention, 23 control) with 388 infants and toddlers Inclusion criteria: Child expected to remain in the child‐care centre for the duration of trial and should be <36 months of age at the end of data collection and that at least one family member contact could participate in a telephone survey in English Exclusion criteria: not stated Age: Infants and toddlers < 36 months
Interventions	Intervention (see Table 5 for detailed description): Larger training Staff of centres were trained using the Keep it clean training module Control: No intervention but received the same equipment at the completion of the trial
Outcomes	Diarrhoeal rates Not used in this review: Days child absent from child care centre per 100 child days Percentage of days child ill per 100 child days Percentage of days care giver absent from work as a result of illness.
Notes	Location: North Carolina, America Duration: September 2002 to May 2003
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Applied different statistical tests for different nature of variables: "No control variables are included in these descriptive comparisons".
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	"Attrition form the intervention and control groups during the course of the trial was comparable".
Selective reporting (reporting bias)	Low risk	None observed.
Other bias	High risk	"Two significant differences between the 2 trial groups were noted. The total number of children and the number of boys were larger in the intervention classrooms. These differences may have reduced the overall effect of the intervention, because number of children per classroom is a risk factor, and boys tend to stay in diapers longer. In addition, control centres were working hard to get their perceived reward (the free equipment that they were promised at the end of the trial). These 3 factors should have reduced the difference in outcomes between the intervention and control groups, suggesting that the significant differences in illnesses and absences that were found favouring the intervention group are all the more impressive".