Table 2.

Pearl Indices for primary endpoint and other subgroups

		Number of participants	Number of pregnancies	Cycles	Pearl Index (95% CI)*
Primary endpoint
Age ≤35 years (primary endpoint)		2111	40	17 427	2·98 (2·13–4·06)
Intention-to-treat subgroup analyses (n=2265)†
Age (years)
	18–19	140	7	1117	8·15 (3·50–15·8)
	20–24	842	22	6773	4·22 (2·69–6·24)
	25–29	744	8	6298	1·65 (0·75–3·07)
	30–35	385	3	3239	1·20 (0·30–3·12)
	≥36	154	1	1318	0·99 (0·06–4·34)
Body-mass index (kg/m2)
	≤29	2065	39	17 763	2·85 (2·05–3·85)
	>29	200	2	982	2·65 (0·44–8·18)
Race
	Only black	319	11	2009	7·12 (3·70–12·2)
	Only white	1613	19	13 983	1·77 (1·09–2·68)
	Other or unknown (including mixed)	333	11	2753	5·19 (2·70–8·90)
Ethnicity
	Hispanic	651	27	5809	6·04 (4·04–8·62)
	Non-Hispanic	1614	14	12 936	1·41 (0·79–2·28)
Site
	US	1519	26	11 766	2·87 (1·91–4·12)
	Non-US	746	15	6979	2·79 (1·61–4·46)
	European	309	1	2764	0·47 (0·03–2·07)
	Non-European	1956	40	15 981	3·25 (2·35–4·37)
Parity
	0	1472	14	12 280	1·48 (0·83–2·40)
	Parity >0	793	27	6465	5·43 (3·63–7·74)
Education
	Grade school	147	8	1224	8·50 (3·88–15·8)
	High school graduate	419	13	3531	4·79 (2·63–7·88)
	Some college	751	11	5747	2·49 (1·29–4·26)
	College graduate or more	948	9	8243	1·42 (0·68–2·56)
Adherence
	Contraceptive vaginal system never removed temporarily when scheduled to be in*	1706	24	14 843	2·10 (1·37–3·06)
	Contraceptive vaginal system removed at least once temporarily when scheduled to be in*	421	16	3530	5·89 (3·46–9·27)

Data are n, unless otherwise indicated.

^*Subject diary cards were used to determine if the contraceptive vaginal system was removed temporarily (between 2 h and 23 h) on a day when the system was scheduled to be in. Some subjects did not return diary cards, and thus could not be grouped by temporary system removal; thus, the numbers of pregnancies and cycles do not sum to the total number of participants.

^†41 pregnancies included in these analyses.