Tapiainen 2002.

Methods	Double‐blind, placebo‐controlled randomised study
Participants	1277 healthy daycare children the city of Oulu, Finland after screening with tympanometry during an ARI
Interventions	Children unable to chew gum: Placebo group: n = 212: 5 mL of a syrup containing 20 g/L xylitol diluted in water without any other sweeteners (daily doses of 0.5 g of xylitol) Test group: n = 212: 5 mL of a syrup containing 400 g/L xylitol 5 times a day (daily doses of 10 g of xylitol) Syrups administered after meals with a syringe during a period of 5 minutes to maintain a high concentration of xylitol in the oral cavity for as long as practically possible Children able to chew gum: Placebo group: n = 280, control chewing gum with daily dose 0.5 g of xylitol Test group: n = 286: xylitol chewing gum with daily dose 8.4 g of xylitol Test group: n = 287: xylitol lozenges with daily dose 10 g of xylitol Two pieces of chewing gum or lozenges were chewed for at least 5 minutes 5 times a day after meals. 3 of the doses were given by the personnel at the childcare centres during the day and the rest were given by the parents at home.
Outcomes	AOM based on a finding of middle ear effusion in tympanometry (B, C or positive pressure curve) and confirmed with pneumatic otoscopy; A total of 1253 of the 1277 randomised children were eligible for the analysis of the primary outcome
Notes	The daily doses of control and xylitol products were equal to those used in earlier trials The parents began administering the products to their children at the onset of symptoms of ARI
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Quote: "Randomization was performed in blocks of 4 in the mixture groups and in blocks of 3 in chewing gum and lozenge groups, using a random number table to make the proportion of participants in each study group approximately the same at each child care centre."
Allocation concealment (selection bias)	Low risk	Each child was given a unique participation number at the time of the initial screening
Blinding (performance bias and detection bias) All outcomes	Unclear risk	The study was blinded as far as the mixture and chewing gum groups were concerned but open as between the xylitol lozenge and control chewing gum groups
Incomplete outcome data (attrition bias) All outcomes	Low risk	The children who dropped out (n = 24) were excluded from the statistical analysis, but those who prematurely stopped using the products but still visited the clinic (n = 35) were included. The children who dropped out contributed days at risk to the cumulative occurrence analysis for as long as they continued to participate
Selective reporting (reporting bias)	Low risk	None identified
Other bias	Unclear risk	The material was donated by industry. Governmental source of funding. The study authors declared they have a US patent for the use of xylitol in treating respiratory infection