Participant characteristics associated with withdrawal from a large randomized trial of spermicide effectiveness

Table 4 Association between early study experience and failure to complete study*

Experience during first 6 weeks	Total	Did not complete study		Relative Risk (95% confidence interval)
	N	n	%
Completed at least one follow-up visit
yes	925	203	21.9	0.68 (0.53 – 0.87)
no	170	55	32.4	1
Completed at least one pregnancy test within first 4 weeks
yes	1070	250	23.4	0.73 (0.41 – 1.31)
no	25	8	32.0	1
Provided diary information for each day
yes	958	215	22.4	0.71 (0.54 – 0.94)
no	137	43	31.4	1
Used spermicide at every coital act
yes	739	153	20.7	0.70 (0.57 – 0.87)
no	356	105	29.5	1
Of those who completed follow-up visit
Reported medical complaints
yes	437	104	23.8	1.17 (0.92 – 1.50)
no	488	99	20.3	1
Disliked spermicide somewhat or a lot
yes	52	12	23.1	1.05 (0.63 – 1.76)
no	873	191	21.9	1
Distrusted contraceptive efficacy
yes	209	51	24.4	1.15 (0.87 – 1.52)
no	716	152	21.2	1
Disliked timing of application
yes	435	96	22.1	1.01 (0.79 – 1.29)
no	490	107	21.8	1
Complained about messiness
yes	375	76	20.3	0.88 (0.68 – 1.13)
no	550	127	23.1	1
Had problems with insertion
yes	465	105	22.6	1.06 (0.83 – 1.35)
no	460	98	21.3	1
Reported that partner disliked spermicide
yes	208	52	25.0	1.18 (0.90 – 1.56)
no	717	151	21.1	1
Happy with spermicide^†
yes	408	80	19.6	0.82 (0.64 – 1.05)
no	517	123	23.8	1

*Includes only participants in the analysis for at least 6 weeks
^†Did not dislike spermicide, had no side effect/AE, and had a satisfied partner

ISSN: 1471-2288