Table 2.

Probability data for the VTs strategy

Variable	Probability	Distribution for PSA	Source	Comments
Removal of VTs (1st insertion)	0.072	Beta ~ (6, 77)	Phua et al. [14]	Different risk has been predicted for subsequent removal procedures[14]
Removal of VTs (≥2 insertions)	0.171	Beta ~ (7, 34)	Phua et al. [14]
Re-insertion of 2nd VTs	0.25	Beta ~ (25, 75)	NCCWCH [7]	Indifferent risk has been predicted for subsequent insertion procedures[7], which is in line with the suggestion by Sheahan et al.[49]. Distribution for PSA is based on the report that 25 out of 100 children require 2 or more insertions of VTs
Re-insertion of 3rd VTs	0.25	Beta ~ (25, 75)	NCCWCH [7]