Scale which has been validated in many study populations and multiple languages. [11] As has been validated in other studies, we considered a decisional conflict score of 25 or less to be low, corresponding to limited conflict. [11,12] Other variables measured included demographic characteristics, prior HIV testing history, knowledge about HIV/AIDS, attitudes towards HIV testing, type of provider (physician, midwife or nurse practitioner), perceived risk of being HIV positive and reasons for testing or not testing. We calculated a knowledge score as the percentage of correct answers on the 9-item knowledge scale. We measured the uptake of testing as a proportion of those in each arm who underwent HIV testing. For binary variables, we compared proportions between the 2 groups using the x2 test or Fisher’s exact Test. For continuous variables, we assessed for normal distribution using the Kolmogorov-Smirnov test and used the Wilcoxon-Mann Whitney test or Student’s T-test as appropriate. A p-value less than 0.05 was considered statistically significant. To assess non-inferiority with respect to the decisional conflict score, we used a one-sided two group t-test of equivalence in means with equal variances with an equivalence limit difference of 5.625. We then evaluated DCS scores and knowledge scores, stratifying by ethnicity, age, primary language spoken and whether the woman had undergone HIV testing in the past. We conducted an intention-to-treat analysis using CONSORT guidelines, including recommendations on reporting of non-inferiority randomized trials. [13,14] Sample Size Our sample size calculation was based on the primary outcome, decisional conflict score. Because this was a non-inferiority trial, the trial was designed to be able to exclude an actual difference between the abbreviated and standard counseling arms of greater than 5.625 (the non-inferiority margin) with respect to the mean decisional conflict score (DCS) in each group. To calculate our sample size we selected a non-inferiority margin of 5.625 based on investigator judgment of a likely clinically significant difference in DCS. We used a type-I error rate (alpha) of 0.05 with an 80% power, a common standard deviation of 18.75 for the DCS obtained from pilot testing of the DCS instrument, and a one- sided two group t-test of equivalence in means (equal n’s) to arrive at 139 patients in each arm for a total of 278 participants. [15,16] Results Between October 3, 2006 and September 24, 2007, study staff approached 496 pregnant patients initiating prenatal care at the Women’s Health Center at San Francisco General Hospital to participate in the study. We excluded 215 patients from participation in the study. See Figure 1. Of the 281 women randomized to one of the study arms, 3 women were discontinued from the study and excluded from the analysis because they were identified as being ineligible only after randomization. In all 3 cases, the women had been tested for HIV during the index pregnancy prior to the initial prenatal visit at SFGH. Two hundred seventy eight women were eligible and random- ized – 134 (48.2%) in the abbreviated arm (AA) and 144 (51.8%) in the standard arm (SA). Women in the 2 groups were similar at baseline, with no statistically significant differences in age, race/ ethnicity, primary language, type of provider, prior HIV testing history, and time since prior HIV test. See Table 2. There was no significant difference in the proportion of women with low decisional conflict (71.6% in AA vs. 76.4% in SA, p = .37) See Table 3. Likewise, there were no significant differences in mean DCS scores (mean 19.9 in abbreviated vs. 16.0 in standard Pretest HIV Counseling Trial arm, p = .17) and the observed mean difference between the groups of 3.88 (95% CI: 20.65, 8.41) did not statistically exceed the non-inferiority margin. There were no differences in DCS scores when stratifying by primary language spoken, ethnicity, age, and prior HIV testing. (Data not shown.) Similarly, women in the 2 arms expressed similar overall satisfaction with their decision to test or not test for HIV (97.8% in AA vs. 99.3% in SA, p = .36). On the other hand, women in AA had significantly lower mean and median knowledge scores (mean = 78.4%) compared to women in SA (mean = 83.7%, p,0.01). In particular, knowledge scores were significantly lower among women in AA who were Spanish-speakers, Latina, $ 27 years old or had undergone HIV testing in the past. (Data not shown.) In comparing the 9 knowledge items individually, the only question that women in the standard arm were significantly more likely to answer correctly related to the decreased risk of perinatal HIV transmission through the use of antiretroviral medication during pregnancy. (Data not shown.) Overall testing uptake was very high (97.8%) and did not differ significantly between the 2 groups (99.3% in AA vs. 96.5% in SA, p = .12). The most common reason given for testing was ‘‘it’s a good idea to have it as a routine test’’ (90.4%). Other reasons given included: ‘‘concerned about my own health’’ (86.0%), ‘‘concerned about risks to the baby’’ (81.2%), ‘‘because it was offered’’ (80.8%) and ‘‘clinic staff thought it was a good idea’’ (67.2%). There were no significant differences in the reasons given by women between the two groups. See Table 4. There were 6 women in our sample who decided not to take the HIV test. The reasons given included: ‘‘been in a stable relationship for a long time’’ (n = 1 AA; n = 4 SA), ‘‘partner has been tested elsewhere’’ (n = 1 AA; n = 3 SA), ‘‘tested negative before’’ (n = 1 AA; n = 3 SA), ‘‘not in a high risk group’’ (n = 2 SA) and ‘‘not necessary, as I have no chance of being positive’’ (n = 2 SA). Of the 278 women enrolled, 247 (89%) returned for a follow-up visit and completed the post-disclosure questionnaire (median time to follow-up visit = 2.7 weeks). Overall, 11.2% of women enrolled in the study were lost to clinical follow-up between initial prenatal visit and medical follow-up visit, 13 women in the abbreviated arm (9.7%) and 18 women in the standard arm (12.5%). At the time of the follow-up survey, all but one participant reported feeling glad about their decision to test or not test (100% in AA vs. 99.2% in SA, p = .33). The only woman reporting not feeling glad about her testing decision was one of the 6 study participants who had not undergone testing. Among the women who responded they were glad about their decision regarding testing, 2 (0.8%) were women who had decided not to take the test. There were no significant differences among women in the 2 arms reporting their comfort waiting for test results (91.7% in AA vs. 91.1% in SA, p = .85) as well as stating they knew as much about HIV/AIDS as they wanted to (74.4% in AA vs. 77.8% in SA, p = .53) and had their questions related to HIV answered (97.5% in AA vs. 95.1% in SA, p = .32). Discussion This study suggests that streamlining the pre-test consenting process, while associated with lower knowledge, does not compromise patient decision making or satisfaction regarding HIV testing. Studies in Scotland have shown that provider- performed HIV counseling and testing is associated with increased uptake of HIV testing in the perinatal setting and is equally acceptable as testing strategies involving passive HIV testing education. [17] Moreover, a cross-sectional study of English and Spanish-speaking prenatal patients found that nearly 70% of PLoS ONE | www.plosone.org 3 April 2009 | Volume 4 | Issue 4 | e5166