Table 2.

Proportion of total drug effect at selected time points in relation to proportion of mean observation period completed (mean observation period = 38.9 weeks). The larger the ratio at given time points, the more the observed effect is in excess of an assumed constant prophylactic effect over the mean observation period.

Week	Percentage of total drug effect (95% CI)	Percentage of mean observation period completed	Ratio
3	20.6 (10.9–30.3)	7.7	2.7
6	50.3 (37.3–63.3)	15.4	3.3
12	69.0 (55.1–82.8)	30.9	2.2
24	101.0 (94.6–107.3)	61.8	1.6
39	104.4 (99.2–109.7)	100.4	1.0

CI, confidence interval.