Five hundred eighty-three women were screened and 446 were randomized at the two study sites (). Of the 137 women excluded, most were excluded as they were unlikely to become pregnant in the next year because they were currently pregnant (n=27); had undergone a hysterectomy (n=7) or tubal ligation (n=18); had an intrauterine device in place (n=22); had a partner who had undergone a vasectomy (n=7); or were aged >45 years (n=22). In addition, 34 women were excluded who planned to relocate or did not have a telephone.
Flow of participants through trial
The women randomized had diverse socioeconomic and ethnic backgrounds. While most had some form of health insurance, only one third reported a relationship with a primary care provider. Although few women (4%) stated that they were trying to become pregnant, 14% reported that they wouldn’t mind becoming pregnant. However, in the 6 months prior to enrolling, this group of women had experienced considerable risk for unintended pregnancy, as more than half reported one or more episodes of vaginal intercourse with a man without the use of any form of contraception.
At baseline, knowledge of folate was limited in both groups; 26% of the women knew that folate can prevent birth defects, and 9% reported the recent use of a folate supplement. However, 85% of the women were interested in learning about what vitamins they should take, and 70% expressed interest in learning how to prevent birth defects. Immediately after receiving computerized counseling about folate, 92% of the women reported that they had learned something from the module, 82% reported that they would use the information they received, and another 12% stated they might do so. Most (86%) reported that they would implement the knowledge, and another 10% reported that they might recommend the module to a friend.
Attempts to contact participants were initiated 6 months after enrollment, and were completed an average of 7 months after enrollment. In total, 265 women completed follow-up phone interviews. The number and characteristics of the women who were lost to follow-up were similar between groups. Baseline reproductive histories were similar between women who subsequently did and did not complete follow up. However, women were less likely to complete the follow-up if they were enrolled at the county clinic, had lower incomes, had not completed a college education, and were self-identified as black. At baseline, women who were subsequently lost to follow-up were less likely to know that folate can prevent birth defects (OR=0.43, 95% CI=0.28, 0.67) and less likely to report the recent use of a folate supplement (OR=0.56, 95% CI=0.28, 1.14).
At follow-up, when it was assumed that the women who were lost to follow-up had learned nothing from the intervention, women in the intervention group were almost twice as likely to know that folate can prevent birth defects (relative risk [RR]=1.72, 95% CI=1.32, 2.23). Women in the intervention group were also significantly more likely to report having used a folate supplement in the last few months (RR=1.54, 95% CI=1.12, 2.13). Other outcomes assessed at follow-up are shown in . In analyses adjusted for age, race, income, insurance, education, and site of enrollment and weighted for propensity for loss to follow-up, women in the intervention group were more likely to know that folate can prevent birth defects (OR=4.19, 95% CI=1.98, 8.85) or to have used a folate supplement (OR=1.55, 95% CI=0.88, 2.72).
Intervention effect on knowledge and use of folate supplements among all subjects randomizeda
In analyses of change from baseline knowledge and the use of folate (that included only subjects who completed follow-up), women in the intervention group were more likely to have learned about folate and to have started folate supplementation (). A woman’s age, race, education, income, marital status, and parity were not associated with whether she learned something about folate from the video doctor.
Change in knowledge and use of folate supplements by intervention groupa