. 2019 Mar 23;9(3):e024324. doi: 10.1136/bmjopen-2018-024324

Table 5.

Screening test uptake and colonisation status transitions between screening and delivery

Screening uptake
Parameter	Input data	Data source
Screening uptake rate	90% [Sensitivity analysis – 75%–95%]	Expert group consensus agreement
Colonisation status transition
‘Transition rate’ from group B Streptococcus (GBS+) at 36 weeks to GBS- at delivery*	Base case 1: 25% Base case 2: 17% [Sensitivity analysis 11.7%–40%]	Valkenburg-van den Berg et al. 2010,²⁸ Di Renzo et al 2015⁵² and expert group consensus agreement
‘Transition rate’ from GBS- at 36 weeks to GBS+ at delivery*	Base case 1: 7.1% Base case 2: 4.8% [Sensitivity analysis 3.3%–12%]	Valkenburg-van den Berg et al. 2010,²⁸ Di Renzo et al 2015⁵² and expert group consensus agreement

*NB: Based on the data available, it is not possible to distinguish between women who have an incorrect screening result (ie, false positive or false negative) and whose true colonisation status remains unchanged at delivery, and those who had a correct screening result (true positive or true negative) and then transition to a different colonisation status at delivery.