TABLE 4.

Rate of switching of resistance of S. pneumoniae and H. influenzae to CoT between two consecutive samples^a

Sequence of test results	Trial arm	No. of occurrences	Pb	Total person-years from first to second tests	Ratec	P (placebo vs CoT)d
S. pneumoniae
Sensitive→sensitive	Placebo	9	0.21	25.2	0.36	0.85
	CoT	6	0.19	15.3	0.39
Sensitive→resistant	Placebo	33	0.79	25.2	1.31	0.18
	CoT	25	0.81	15.3	1.63
Resistant→sensitive	Placebo	18	0.23	30.7	0.59	0.002
	CoT	12	0.10	61.9	0.19
Resistant→resistant	Placebo	59	0.77	30.7	1.92	0.67
	CoT	114	0.90	61.9	1.84
H. influenzae
Sensitive→sensitive	Placebo	11	0.61	9.3	1.19	0.05
	CoT	7	0.28	12.1	0.58
Sensitive→resistant	Placebo	7	0.39	9.3	0.75	0.11
	CoT	18	0.72	12.1	1.48
Resistant→sensitive	Placebo	6	0.46	7.1	0.84	0.63
	CoT	9	0.39	13.4	0.67
Resistant→resistant	Placebo	7	0.54	7.1	0.98	0.86
	CoT	14	0.61	13.4	1.04

^aSpecimens with missing resistance results were excluded.

^bThat is, the probability of a subsequent test result being resistant versus sensitive conditional on the first test result.

^cThe 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.

^dCalculated using cause-specific hazards for subsequent test result being resistance versus sensitive. A global test for differences between placebo and CoT across all four sequences for S. pneumoniae was performed (P = 0.005). A global test for differences between placebo and CoT across all four sequences for H. influenzae was performed (P = 0.29).