Table 4.

Summary comparison of average rates of positivity for F-MC between MS patients, siblings and CBU controls

Group	N	Average rate* (95% CI)	Relative rate** (95% CI)	p-value**
CBU	30	0.009 (0.003, 0.02)	-
MS-prior birth of a male child	27	0.04 (0.03, 0.06)	5.56 (1.40, 21.97)	0.015
MS-reported never pregnant	24	0.04 (0.03, 0.06)	5.87 (1.49, 23.16)	0.012
SIB	22	0.02 (0.01, 0.03)	2.27 (0.45, 11.46)	0.32

^*Average positivity rates for each group (defined for an individual as the proportion of positive results observed in 22 amplification cycles), with exact 95% Poisson confidence intervals.

^**Relative positivity rates for each group, using the CBU group as the reference. (Estimates from Poisson regression).

^†p-values for comparison of estimated positivity rates in each group to rate in CBU group.