TABLE 3.

Rate of carriage switching of S. pneumoniae and H. influenzae between two consecutive samples

Sequence of test results	Trial arm	No. of occurrences	Pa	Total person-years from first to second tests	Rateb	P (placebo vs CoT)c
S. pneumoniae
No carriage→no carriage	Placebo	77	0.53	52.0	1.48	0.10
	CoT	94	0.47	77.9	1.21
No carriage→carriage	Placebo	68	0.47	52.0	1.31	0.61
	CoT	108	0.53	77.9	1.39
Carriage→no carriage	Placebo	78	0.43	67.7	1.15	0.44
	CoT	94	0.42	90.0	1.04
Carriage→carriage	Placebo	105	0.57	67.7	1.55	0.50
	CoT	131	0.58	90.0	1.46
H. influenzae
No carriage→no carriage	Placebo	168	0.73	82.4	2.04	0.67
	CoT	237	0.77	119.5	1.98
No carriage→carriage	Placebo	62	0.27	82.4	0.75	0.12
	CoT	71	0.23	119.5	0.59
Carriage→no carriage	Placebo	71	0.73	36.8	1.93	0.02
	CoT	71	0.60	47.2	1.51
Carriage→carriage	Placebo	26	0.27	36.8	0.71	0.11
	CoT	47	0.40	47.2	1.00

^aThat is, the probability of a subsequent test result being carriage versus no carriage conditional on the first test result.

^bThe rate column normalizes probabilities to total person-time at risk between tests, which differs between groups because of higher survival rates associated with CoT treatment.

^cCalculated using cause-specific hazards for subsequent test result being carriage versus no carriage. A global test for differences between placebo and CoT across all four sequences for S. pneumoniae was performed (P = 0.18). A global test for differences between placebo and CoT across all four sequences for H. influenzae was performed (P = 0.04).