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Prevention of Gonorrhea and Chlamydia Through Behavioral Intervention: Results of a Two-Year Controlled Randomized Trial in Minority Women

Shain, Rochelle N. PhD*; Piper, Jeanna M. MD*; Holden, Alan E.C. PhD*; Champion, Jane Dimmitt PhD; Perdue, Sondra T. DrPH; Korte, Jeffrey E. PhD*; Guerra, Fernando A. MD, MPH§

Sexually Transmitted Diseases: July 2004 - Volume 31 - Issue 7 - p 401-408
doi: 10.1097/01.olq.0000135301.97350.84

Background: Sexually transmitted disease (STD), including AIDS, disproportionately affects African-American and Hispanic women.

Goal: To evaluate efficacy of standard and enhanced (addition of optional support groups) gender- and culture-specific, small-group behavioral interventions, compared to interactive STD counseling, in high risk minority women for two years.

Methods: Women with a non-viral STD were treated and enrolled in a randomized trial. Follow-up screens and interviews occurred at 6 months, 1 year, 18 months (short interview, optional exam) and 2 years. The primary outcome was subsequent infection with chlamydia and/or gonorrhea. Secondary outcomes included risky sexual behaviors. We employed logistic regression based on intention-to-treat.

Results: Data from 775 women were included; the retention rate was 91%. Adjusted infection rates were higher in the controls in Year 1 (26.8%), Year 2 (23.1%), and cumulatively (39.8%) than in the enhanced (15.4%, P = 0.004; 14.8%, P < 0.03; 23.7%, P < 0.001, respectively) and standard (15.7%, P = 0.006; 14.7%, P = 0.03; 26.2%, P < 0.008, respectively) intervention arms at these time points. Enhanced-intervention women who opted to attend support groups (attendees) had the lowest adjusted infection rates in Year 1 (12.0%) and cumulatively (21.8%). Intervention women in general, but particularly attendees, were significantly less likely than controls to have repeat infections. Multiple partners and unprotected sex with an untreated or incompletely treated partner helped explain group differences in infection.

Conclusions: Risk-reduction interventions significantly decreased both single and multiple infective episodes with chlamydia and/or gonorrhea and risky sexual behaviors in the two-year study period. Support-group attendance appeared to contribute additional risk reduction in Year 1.

Mexican- and African-American women assigned to two forms of behavioral intervention had significantly lower rates of chlamydia and/or gonorrhea than controls in both years of a two-year randomized trial.

From the *Department of Obstetrics & Gynecology, Microbiology, and School of Nursing, The University of Texas Health Science Center at San Antonio, §San Antonio Metropolitan Health District, San Antonio, Texas

The authors thank all staff at our research clinic and at the San Antonio Metropolitan Health District STD clinic who made this project possible. The authors also thank Kyle Sterneckert for his helpful contributions in data analysis.

Supported by a grant (U01 AI40029) from the National Institute of Allergy and Infectious Diseases

Correspondence: Rochelle N. Shain, PhD, Department of Ob/Gyn, University of Texas Health Science Center at San Antonio, 7703 Floyd Curl Drive, San Antonio, TX 78229. E-mail:

Received for publication September 19, 2003, revised January 21, 2004, and accepted February 11, 2004.

THE AIDS EPIDEMIC has refocused world attention on the need to prevent sexual transmission of infection. Although sexually transmitted diseases (STDs) impact all segments of society, there are subpopulations at greatest risk. Within the United States, African-Americans and Hispanics suffer the greatest impact, with women bearing the brunt of disease.1–3 In 2001, 65% of new chlamydia,1 79% of new gonorrhea,1 and 81% of new HIV diagnoses4 in women occurred in African-Americans and Hispanics. When compared by population-based rates (per 100,000), differences are even more striking: chlamydia rates for African-American (1646) and Hispanic women (736) far exceeded those for non-Hispanic Whites (192).1 AIDS incidence rates (per 100,000) were 47.8 and 12.9 among African-American and Hispanic women, respectively, compared to 2.4 among Whites.4 African-American and Hispanic women aged 15 to 24 were most dramatically impacted by STDs. For example, their chlamydia rates were approximately 8,200 and 2,800 per 100,000; 25- to 29-year-old women were also at high risk, with rates of approximately 2,600 and 1,300, respectively.1

Behavioral intervention to reduce high risk behavior and ensuing infection remains critical, particularly for young (age <30), heterosexual minority women. There are few controlled randomized trials using biologic outcomes based exclusively on laboratory diagnoses.5–11 Of these, three showed reduced infection6–8,10 and only one focused on U.S. minority women.8 Additional successful trials either combined laboratory and presumptive diagnoses12 or employed HIV serologic testing but based STD incidence on clinical diagnosis or symptom reports.13 Another,14 using chart reviews of incident STIs and urine specimens at 12 months, found no differences in incident STD overall, only GC differences in men (charts). Our prior trial (Project SAFE) showed that a theory-based, behavioral, risk-reduction intervention, designed specifically for low-income African- and Mexican-American women, helped reduce infection with chlamydia and/or gonorrhea by approximately 38% during one-year follow-up.8

In the current study (Project SAFE 2), we sought to 1) confirm our prior findings, 2) determine longer-term efficacy (any time during 2-year follow-up) with respect to any infection with chlamydia and/or gonorrhea and repeat infective episodes, 3) determine if efficacy changed through time, i.e., from Year 1 to Year 2, as shown in adjusted odds ratios and 4) in a second intervention arm, determine the additional benefit of offering 5 optional monthly support groups following the standard intervention. We theorized, based on positive findings from other work15 (confirmed in multiple health fields16–19) and experience from our first study (some participants wanted more than three intervention sessions), that women in need of additional discussion and support for risk reduction would benefit from the option of support-group attendance. Although the others would not have to participate, perhaps knowing that the option was available might help all women offered additional support feel more secure. Making support-group attendance mandatory, moreover, would have limited recruitment and thereby would have introduced a bias difficult to measure. We also believed that optional attendance (following 9 hours of intervention) would be more realistic in a clinical or community setting.

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Study Procedures

Institutional review boards at the University of Texas Health Science Center and the San Antonio Metropolitan Health District (SAMHD) approved this study. All study-related medical care was provided at a dedicated research clinic in conjunction with the SAMHD STD Clinic. Mexican-American and African-American women diagnosed with gonorrhea, chlamydia, syphilis, or trichomonas in public-health clinics were referred to our study for potential participation. Eligible, English-speaking (to maximize homogeneity across ethnic groups), reproductive-age women (15–45 years old), who could be contacted were offered enrollment. Fourteen-year-olds were enrolled only at the request of the Health Department or guardians and after special IRB permission was obtained. Because we had few addicts or alcoholics in our first study, we did not anticipate the need to screen for substance use; nor did our intervention address drug and alcohol use, except in regard to their relationship with risky sex. We unexpectedly enrolled a much higher-risk sample (regarding substance use) than our previous cohort and did not appreciate this in time to eliminate potential participants from enrollment nor to stratify their group assignments. We subsequently considered all substance users eligible to participate, excepting those who, at baseline, were very young (<18 years), used hard drugs and had dropped out of middle or high school. Clearly, the intervention was not designed to overcome these triple risks; however, women with two of these risks were eligible. Nor was it designed to benefit 14- to 15-year-old sexually abused girls; we previously demonstrated the intervention’s inadequacy for this group,20 but not in time to eliminate them from enrollment. We therefore also considered these adolescents ineligible for the current study. We allowed all of these adolescents to continue participation because we were interested in learning more about their perceptions and behavior and to maintain good community relationships.

Intervention efficacy was evaluated by controlled randomized trial. The primary outcome was subsequent infection with chlamydia or gonorrhea. HIV prevention could not be evaluated due to low prevalence in our community. Secondary outcomes included risky sexual behaviors. Participants were enrolled within one month of treatment of their baseline infection (mean, 15.6 days, median, 15 days). After obtaining written consent, participants were counseled and interviewed. They received individual, interactive counseling (15–20 minutes) based on CDC guidelines and results from our first intervention trial.8,21,22 We emphasized full treatment for themselves and their partners; avoidance of sexual intercourse until treatment was completed; mutual monogamy, as opposed to multiple, particularly concurrent, relationships; taking time between partners to be selective; consistent and correct condom usage; avoidance of douching; and seeking care whenever they suspected infection. Treatment or retreatment was provided to enrollees who were untreated, or who had incomplete treatment, untreated partners, sex before she or her partner completed treatment or any unprotected sex since treatment. Women whose baseline infection was syphilis were not always tested for chlamydia and/or gonorrhea at their referring clinic. Participants without such testing at entry were screened for these infections and treated, as needed.

At the end of the initial visit, participants were randomly assigned to the control group, standard behavioral-cognitive intervention, or enhanced intervention (standard intervention with the option of attending five monthly support-group sessions). The standard intervention, described earlier,8,23 consisted of 3 weekly, small-group, multi-component sessions, each lasting approximately 3 hours. Separate sessions were held for each ethnic group with ethnicity-matched female facilitators. We had adapted the AIDS Risk Reduction Model24 to guide intervention development, supplemented with extensive ethnographic data to ensure suitability to the target population.8,25 Overall goals were to have women recognize their risk for contracting STDs, including HIV; commit to behavior change; acquire necessary skills to effect change; and be vigilant in promptly seeking care for possible infection. Enhanced-intervention support-group sessions lasted approximately 90 minutes and incorporated themes shown in Table 1. Incentive payments for the standard intervention were $25.00 for Session 1 and $15.00 for Sessions 2 and 3; support-group incentives were $5.00 per session. Inexpensive meals (encouraging bonding) and gifts were provided at the 3 intervention sessions.



Participants were interviewed, examined, screened for infection, and treated when indicated at targeted 6-month, 1- and 2-year visits. The 18-month interview was brief with optional screening. Incentives were $25.00 for initial and 6-month visits, $15.00 at 18 months, and $50.00 at annual visits. Gonorrhea and chlamydia testing (including off-site) was performed on endocervical samples using GEN-PROBE PACE 28 (GEN-PROBE Co., San Diego, CA). HIV testing was offered at every visit. Participants were offered a test-of-cure following treatments. They were encouraged to return for any symptoms or concerns about reinfection, for testing and treatment (problem visits). Women were questioned extensively regarding health care obtained elsewhere; with their permission, records were obtained and thoroughly reviewed. In conjunction with SAMHD, we reviewed reportable disease records to identify infections otherwise possibly missed. We thus achieved broad ascertainment of infections diagnosed and treated outside our research clinic.

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Statistical Analysis

Randomization was similar to that used in our prior STD intervention trial.8 At completion of the initial visit, all participants selected a convenient day to begin potential intervention. Each day had been randomly assigned in advance to represent control-group, standard, or enhanced intervention. As described for our prior study, after selecting a day, participants were informed of their group assignment. This approach was selected 1) to maximize similarity between the groups in motivation in that all participants had to agree to select a start-day and 2) to minimize resentment of group assignment in that women believed they ‘selected’ their group. Control-group women were informed that the intervention would be available to them after study completion. Although not a masked study, group status did not appear on interviews or clinic records. Participants were asked their group status only at the end of follow-up interviews to ascertain intervention benefits.8

All laboratory tests positive for gonorrhea and chlamydia, including on- and off-site non-routine (e.g., problem, prenatal) visits, were counted in the interval in which they occurred. Infections diagnosed within 30 days of enrollment were not counted. Testing performed within 30 days of treatment was considered test-of-cure (not counted). Two women were not counted as ‘infected’ because their only infection occurred before timely completion of the intervention or first support group. In statistical models predicting reinfection, we controlled for time between enrollment and follow-up visits.

Chi-square analysis, Student’s t test, one-way ANOVA, and multiple logistic regression were used to assess group differences in characteristics. Chi-square and multinomial regression analyses were used to assess associations of behavioral variables and covariates with study group and infection. Logistic regression was used to assess associations of behavior with group and to determine intervention effects, controlling for group differences in characteristics independently related to outcome. The covariate ‘substance risk’ (worst case of all interviews in the time interval) included 3 levels: ultra-high, high, and low/moderate, as defined in Table 2. The covariate ‘obtaining additional GC/CT testing,’ addressed tests in excess of those from routine visits by counting screens within a time interval. We conducted analyses comparing enhanced and standard intervention to controls (3-group model), based on intention to treat. We also conducted analyses (4-group model) with enhanced-intervention participants separated into those who opted to attend support groups (attendees) and those who did not (non-attendees). We performed additional Year-2 analyses (based on women with data from both years), controlling for infection in Year 1 to determine: the relationship between Year 1 and Year 2 infection, and whether intervention impact in Year 2 occurred regardless of infection status in Year 1.



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A total of 585 Mexican-American and 190 African-American women were randomly assigned to enhanced intervention (262), standard intervention (237), or control group (276). An additional 53 women initially enrolled were determined to be ineligible because of: protocol violations (5), severe mental illness (2), criminal activity at our clinic (1), being sexually abused 14- to 15-year-olds at baseline (16), or hard-drug using, 14- to 17-year-old, school dropouts at baseline (29). Enrollment began in March 1996 and ended in June 1998. Of 1,271 potentially eligible women contacted, 32.7% declined participation, 1.6% were ineligible at enrollment, and 4.2% were ineligible subsequent to enrollment. Most participants were treated elsewhere before enrollment; however, 16.8% obtained initial treatment and 21.9% were retreated at our clinic (no group differences in percent treated or retreated at our clinic). Intervention show rates (before the 6-month visit) were 96% for at least 1 session, 92% for at least 2 and 86% for all 3. Among women assigned to enhanced intervention, 63% chose not to attend optional support groups; 37% attended at least one before their 6-month visit; 26% attended two or more.

Year-1 and Year-2 retention rates (based on the 775 eligible women) were 91.4% (N = 709: enhanced, 90.1%; standard, 92.4%; control, 92.0%) and 91.2% (N = 707, enhanced, 90.8%; standard, 89.9%; control, 92.8%), respectively. There were no group differences in retention rates. Within the enhanced-intervention group, however, the subgroup of women who chose the option to attend support groups had higher retention rates than those who did not (cumulatively, 95.9% vs. 84.2%, P = 0.004), resulting in 40% attendance among retained women. Support-group non-attendees subsequently lost to follow-up (as opposed to those retained) were more likely at baseline to have had >1 partner in the last year (P < 0.06), and to have had syphilis (P < 0.001). Syphilis was not a marker for subsequent infection with chlamydia and/or gonorrhea in our sample but >1 partner was. The potential bias is therefore conservative in that it might make it more difficult to show a reduced infection rate among attendees relative to non-attendees.

In addition to scheduled follow-up, chlamydia and gonorrhea screening was performed at 809 non-routine visits (228 off-site, no group differences in percent off-site). Women who missed an annual follow-up, but were infected earlier that interval were included in corresponding analyses. Participants testing negative at their Year-2 visit with ≥2 consecutive prior missed visits were excluded from cumulative analysis because of too many missing data points. Thirty-three women (8 were infected) with Year-1 visits were lost to follow- up at Year 2. Twenty-seven women missing their Year-1 visit returned at Year 2 (6 were infected). Only those women with laboratory data from both years (676) and the 14 infected cases noted above (8 + 6) were included in the 2-year cumulative analysis. Analyses included 709 women in Year 1, 703 in Year 2, and 690 cumulatively. Analysis of number of partners included 584 women with complete (4 visits) follow-up data.

Characteristics of the cumulative analysis sample are provided in Table 3. Low levels of income and education characterize the population; ages range between 14 and 43 with 53% under 20 years, 80% under 25 years, and 91% under 30 years. Few women (<10%) were married and over 60% had >1 partner in the last year. Despite randomization, several risk characteristics differed among groups (Table 3). Most importantly, one or both intervention groups had a higher percent of women who: were young (<20 years), were in the high or ultra-high substance risk categories [as defined in Table 2], and/or had multiple additional screens for GC and CT (regardless of infection status). Support-group attendees, compared to non-attendees, had less education (10.1 vs. 10.7 years, P < 0.02), were younger (<20 years, 62.4% vs. 49.6%, P = 0.056), and had more partners in the last 3 and 6 months (≥3 men, 12.9% vs. 5.0%, P < 0.03; 26.9% vs. 12.9%, P = 0.007, respectively). Additionally, fewer attendees (59.1% vs. 71.2%, P = 0.056) were in the low/moderate risk substance group during the study. More attendees than non-attendees tended to have ≥3 additional screens for GC and/or CT.



Baseline age (<20, 20–29, ≥30), education, and ethnicity and follow-up measures of exposure time (Year 1 only), seeking additional testing (1, 2 or ≥3 screens), and substance-use risk (low/moderate, high, or ultra-high) were controlled in multiple logistic-regression analysis, because group differences were potentially important and these variables were independently associated with infection. One intervention goal was increasing health-seeking behavior with any suspicion of possible STD. Having extra testing, however, increases opportunity to detect infection; this is vigilance if it occurs independently of infection. Significantly more enhanced- and standard-intervention women than controls had ≥2 additional screens, independent of infection status (P < 0.001, P = 0.008, respectively). Level of substance use during follow-up, as opposed to baseline, was utilized as a covariate because as trust developed over time, more participants admitted illegal behaviors. Ongoing substance use was strongly related to infection (2-year cumulative infection rates: low/moderate risk, 29.3%; high risk, 45.9%; and ultra-high risk, 74.1%, P <0.001). Of the 58 women in the ultra-high risk group (in any time period during 2-year follow-up), only 8 were controls.

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Results by Substance Use Categories

Because of the strong relationship between substance use and infection and the disproportionate percent of intervention women in the higher risk categories, we first present data according to substance risk category, adjusted for the remaining covariates. The sample in our first intervention trial8 was most similar to, but still lower risk than, the low/moderate risk subgroup: 16.8% of the former versus 24.9% of the latter reported any drug use in Year 1. Table 4 shows that in the low/moderate risk group, both enhanced and standard intervention groups were significantly less likely than controls to be infected in Year 1 (unadjusted infection rates 13.2% and 14.0% vs. 24.1%); effect sizes (percent reductions in infection relative to the control group) based on unadjusted infection rates were 45.2% (56.4% adjusted effect size) and 41.9% (57.7% adjusted), respectively. Only a trend was observed in Year 2; however, a significant effect was found for each intervention group in the cumulative 2-year period (unadjusted effect sizes were 23.1% [46.2% adjusted] and 27.2% [48.3% adjusted], respectively). Of interest, within the enhanced-intervention group, women with low/moderate substance risk who chose to attend support groups did not realize additional benefit in any year.



Sample sizes are considerably smaller in the high risk group; therefore, power is too low to show significance for all but the most dramatic differences. In the high risk group, both intervention groups were slightly less likely than controls to be infected in Year 1. Women who chose to attend support groups had the lowest probability of being infected (aOR, 0.63) in this year. The study effect in the high risk group was strongest in Year 2: unadjusted and adjusted effect sizes for enhanced and standard groups were 48.1% (54.1%) and 30.8% (21.6%), respectively. However, support-group attendance provided no benefit in this year. Cumulatively, enhanced and standard groups tended to have lower infection rates than controls (aORs 0.60, 0.66).

Due to the very small sample size of the ultra-high risk group and the very few control subjects in this category, estimates are unstable. However, two overall trends can be observed: there is no overall study effect in Year 1, but a very strong trend in Year 2 (aORs for enhanced and standard groups were 0.28, 0.15); and support-group attendance conferred additional benefit only in Year 1 and cumulatively (by virtue of Year 1).

In sum, the Year-1 study effect (both intervention arms) occurred only in the low/moderate risk group, and the Year-2 effect, primarily in the higher risk substance groups. Benefit of actually attending support groups was seen only in the higher risk substance groups and only in Year 1. Due to the impact of substance use on infection rates and the differential intervention impact by level of use, further logistic regression analyses and resulting effect sizes are adjusted by substance-risk group as well as the other covariates. Adjusted infection rates and effect sizes provide concise summaries of final results.

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Overall Results

In adjusted analyses, significant reductions in GC/CT infection were observed for women assigned to enhanced and standard interventions in all intervals (3-group model, Table 5). Over the 2-year study period, women in the enhanced and standard interventions were respectively 40.5% and 34.2% less likely to be infected than controls (P < 0.001, <0.008). Examining results separately by year revealed that enhanced and standard intervention women were 42.5% and 41.4% less likely than controls to be infected in Year 1 (P = 0.004, 0.006) and 35.9% and 36.4% less likely in Year 2 (P < 0.03, 0.03). We performed additional logistic regression analysis of Year 2 infections, including an interaction term testing for differential intervention impact on women with and without Year-1 infection. The interaction was not significant and subsequently dropped. In a Year-2 infection model controlling for Year-1 infection (no interaction term), we found that women with Year-1 infections were significantly more likely to be infected in Year 2 (35.2% vs. 16.2%, P < 0.001) and that enhanced and standard-intervention women remained significantly less likely than control counterparts to be infected in Year 2 (aOR, 0.56, P = 0.02; aOR, 0.59, P < 0.05).



Analyses of the effects of exercising one’s option to attend support groups (4-group model, Table 5) indicated that attendees and non-attendees were respectively 45.2% and 37.2% less likely than controls to be infected in the 2-year study period (P < 0.004, <0.01). In Year 1, attendees and non-attendees, respectively, were 55.2% and 34.0% less likely than controls (P < 0.005 and 0.053) to be infected. Attendees were 32.2% less likely to be infected in Year 1 than non-attendees. In Year 2, attendees were 41.6% less likely to be infected (P < 0.05) than controls, whereas the 32.0% adjusted effect size for non-attendees did not reach statistical significance. Attendees were only 14.0% less likely to be infected in Year 2 than non-attendees.

Logistic regression analyses of repeat infections (based on women with 6 month, Year 1, and Year 2 data) indicated that women in enhanced (aOR 0.42, P = 0.003) and standard (aOR 0.51, P < 0.03) intervention groups were also less likely than controls to have multiple infective episodes any time during the study (adjusted rates: 7.2% and 8.2% vs. 17.3%, respectively). Support-group attendees (aOR 0.35, P = 0.009) and non-attendees (aOR 0.47, P < 0.03) were less likely than controls to have multiple infections any time during the study (adjusted rates: 6.0% and 8.2% vs. 17.3%, respectively). Attendees had a 27% lower adjusted risk than non-attendees of having multiple infections. When examining intervention effects stratified by substance risk, we found that significantly lower repeat infection rates relative to controls were found only in the low/moderate risk group; a trend existed in the higher risk substance groups only for attendees. Analyses also showed that enhanced (aOR 0.38, P = 0.008) and standard-intervention (aOR 0.39, P = 0.01) participants were significantly less likely than the control group to be infected in both Years 1 and 2 (adjusted rates: 4.3% and 4.3% vs. 10.8%, respectively). Attendees (aOR 0.22, P = 0.009) and non-attendees (aOR 0.52, P < 0.11) were less likely than controls to be infected in both years (adjusted rates: 2.5% and 5.7% vs. 10.8%). Attendees had a 56% lower adjusted risk of being infected in both years than non-attendees. When examining intervention effects stratified by substance risk, we found that significantly lower rates of multiple year infections relative to controls were found only in the low/moderate risk group; a strong trend existed in the higher risk substance groups only for attendees.

Ongoing analysis of behaviors contributing to reduced infection rates at various follow-up periods (Table 6) demonstrated that multiple partners and noncompliance with treatment protocols (having unprotected sex with an untreated/incompletely treated partner after the baseline infection) were significantly related to infection. However, simple measures of condom use and unprotected acts were not; they are heavily dependent upon context21,22,26,27 and require more extensive analysis. Significantly fewer women in both intervention groups were noncompliant with treatment protocols and significantly fewer had multiple partners in any follow-up year. Significantly more enhanced-intervention participants, particularly support-group attendees, and standard-intervention participants (at P = 0.052) had only one partner during the entire study.



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In the current study, we unexpectedly enrolled a much higher risk cohort than in our former intervention trial (40.7% of current vs. 16.8% of former participants reported any drug use during Year 1). Despite randomization, women in the higher risk substance-use categories were disproportionately assigned to the intervention groups. Due to the strong association between substance abuse and STD found in our study and in others,28–31 we were compelled to consider effects by substance risk category. Standard-intervention women had basically the same intervention experience as participants in our original study8 and the low/moderate substance risk group (24.9% drug use in Year 1) was most similar to our entire prior cohort (16.8%). Therefore, standard intervention women in the low/moderate substance-risk group (22.8% drug use in Year 1) were used to compare unadjusted Year-1 infection rates and effect sizes in the current study to those in the prior trial.

The 3-session culture- and gender-appropriate behavioral intervention provided in the current study was nearly identical to that provided to women in our former trial.8 Results confirmed its efficacy in preventing gonorrhea and/or chlamydia among relatively young, African-American and English-speaking Mexican-American women for one year in the standard intervention group. The previously published effect size, 38%, is similar to the 42% (Year 1, unadjusted) reported now for low/moderate substance risk women in this intervention arm. Unadjusted infection rates are also similar: 14.0% for standard-intervention women versus 24.1% for controls in the current study and 16.8% for intervention women versus 26.9% for controls in the original trial.8 Additionally, covariate-adjusted analyses among all standard-intervention women demonstrated a similar Year-1 adjusted effect size of 41%.

Analyses also showed that effects of both enhanced and standard intervention lasted at least 2 years (any infection during the 2-year study period). Other randomized trials of sexual risk reduction interventions typically do not extend beyond 12 months; none to our knowledge followed the same cohort for 2 years. Retention rates and effects reportedly decline over time.5,32 In this study, retention rates remained high (91%) and effects, although declining, remained significant during the second year. Logistic regression analysis of Year-2 data, controlling for Year-1 infection, showed that the two intervention arms reduced infection among women not previously infected in Year 1 and had a protective effect on those already infected in the prior year. Moreover, women in both intervention arms experienced significantly fewer multiple infective episodes than controls during the 2-year period (effect sizes >50%).

Of interest, analyses stratified by substance risk showed that the intervention effect in Year 1 occurred primarily in the low/moderate risk group. These analyses showed a decline in effect for low/moderate substance risk women in Year 2, but a large increase in effect for higher risk women. Despite very limited intervention focus on the effects of substance use on risk behavior, higher risk substance users derived benefit in the second year. Given their disrupted lifestyles, it may have taken them longer to effect change. However, infection rates were still very high, particularly for ultra-high risk participants, suggesting that drug treatment be combined with sexual risk reduction intervention for such women.29

There was little difference in intervention effect between women assigned to enhanced and standard intervention. However, we tested the effect of actually attending support groups among enhanced-intervention women. Although support-group attendance was not required, we believe these analyses are useful and of interest. Relative to standard-intervention, additional infection-rate reduction was found only among women attending one or more sessions; just knowing support-groups were available had no effect. Of interest, 1) women who chose to attend were younger, less educated, had more baseline partners, and were more likely to be in the higher risk substance categories, indicating higher overall risk; and 2) only women in the higher risk substance groups achieved additional risk reduction from attendance. It would appear that women in the low/moderate risk substance group did not benefit from additional group support. Also of interest, benefit from support-group attendance occurred primarily during the first year, while support groups were ongoing. During the second year, the adjusted odds ratio for attendees, relative to controls, weakened to 0.52 from 0.37, whereas non-attendees and standard-intervention participants experienced less change. Nonetheless, the Year 2 infection rate for attendees, as opposed to non-attendees, was significantly lower than that of controls. Of note, attendees were least likely of all groups to experience infection in both years (77% less likely than controls) and to experience multiple infective episodes any time during the study (65% less likely than controls). In the ultra-high risk substance group (although based on very small numbers), support-group attendees appeared to be the only group with reduced cumulative infection rates.

It is possible that enhanced-intervention participants who elected to attend support groups were more motivated to change their sexual behavior and therefore had lower infection rates. Alternatively, they may have attended meetings because they perceived a greater need for support. Indeed, as noted above, attendees were higher risk than non-attendees and only women in the higher risk substance groups benefited from additional support. Additionally, non-attendees’ cumulative infection rates and behaviors were similar to those of standard-intervention participants (not offered support groups). Support-group attendance contributed additional benefit and support-group cessation resulted in decrease of this benefit. These results suggest that support-group attendance was not merely a proxy for motivation in our study.

Our findings are consistent with study results from areas as diverse as sexual behavior, diabetes control, breast cancer, PMS, and smoking cessation, showing support-groups’ beneficial impact.15–19 Our finding that support-group attendance had its greatest impact when they were ongoing suggests the importance of continuing or booster meetings. It is also important to remove attendance barriers: in our downtown setting, $5.00 was insufficient compensation for transportation and parking. Increasing incentives, providing free transportation, or convening groups in participants’ neighborhoods might have increased attendance.

Both interventions were associated with increased health-seeking behavior (repeated health-care visits that included STD testing). Repeated testing allows early detection and rapid treatment which decreases transmission. Because having additional STD screens increases the likelihood of detecting infection, it was controlled in analysis.

Consistent with lower infection rates, women in both intervention arms were more likely than controls to avoid risky behaviors: unprotected sex with an untreated/incompletely treated partner and multiple partners in various intervals. Avoiding the former behavior was associated with a 41% reduction in infection. Having ≤1 partner each year and in the 2-year period, respectively, were associated with 50% and 65% reductions in infection. These behaviors help account for group differences in infection rates.

High intervention attendance and sample retention rates, particularly for a difficult-to-follow population, in conjunction with intensive ascertainment of infection, strengthen generalizability of results. However, generalization to other groups of high risk women requires caution. Due to very low prevalence of HIV in our population, efficacy against HIV seroconversion could not be evaluated. Despite absence of a direct relationship between STD and HIV prevention, behavioral risk reduction that disrupts heterosexual transmission of bacterial pathogens could also prevent heterosexual transmission of HIV.21,33,34

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1.Centers for Disease Control and Prevention. Sexually Transmitted Disease Surveillance 2001. Atlanta, 2002.
2.Eng T, Butler W, eds. The hidden epidemic: confronting sexually transmitted diseases. Washington, DC: National Academy Press; 1997.
3.Aral SO. Sexually transmitted diseases: magnitude, determinants and consequences. Int J STD AIDS 2001;12:211–215.
4.Centers for Disease Control and Prevention. HIV/AIDS Surveillance Report, 2001.
5.Stephenson JM, Imrie J, Sutton SR. Rigorous trials of sexual behaviour interventions in STD/HIV prevention: what can we learn from them? AIDS 2000;14:S115–S124.
6.Kamb ML, Fishbein M, Douglas JM, et al. Efficacy of risk-reduction counseling to prevent human immunodeficiency virus and sexually transmitted diseases: a randomized controlled trial. Project RESPECT Study Group. JAMA 1998;280:1161–1167.
7.Ford K, Wirawan DN, Reed BD, Muliawan P, Wolfe R. The Bali STD/AIDS Study: evaluation of an intervention for sex workers. Sex Transm Dis 2002;29:50–58.
8.Shain RN, Piper JM, Newton ER, et al. A randomized, controlled trial of a behavioral intervention to prevent sexually transmitted disease among minority women. N Engl J Med 1999;340:93–100.
9.Boyer CB, Barrett DC, Peterman TA, Bolan G. Sexually transmitted disease (STD) and HIV risk in heterosexual adults attending a public STD clinic: evaluation of a randomized controlled behavioral risk-reduction intervention trial. AIDS 1997;11:359–367.
10.Elwy AR, Hart GJ, Hawkes S, Petticrew M. Effectiveness of interventions to prevent sexually transmitted infections and human immunodeficiency virus in heterosexual men: a systematic review. Arch Intern Med 2002;162:1818–1830.
11.Orr DP, Langefeld CD, Katz BP, Caine VA. Behavioral intervention to increase condom use among high-risk female adolescents. J Pediatr 1996;128:288–295.
12.Baker SA, Beadnell B, Stoner S, et al. Skills training versus health education to prevent STDs/HIV in heterosexual women: a randomized controlled trial utilizing biological outcomes. AIDS Educ Prev 2003;15:1–14.
13.Celentano DD, Bond KC, Lyles CM, et al. Preventive intervention to reduce sexually transmitted infections: a field trial in the Royal Thai Army. Arch Intern Med 2000;160:535–540.
14.The NIMH Multisite HIV Prevention Trial: reducing HIV sexual risk behavior. The National Institute of Mental Health (NIMH) Multisite HIV Prevention Trial Group. Science 1998;280:1889–1894.
15.Coates TJ, McKusick L, Kuno R, Stites DP. Stress reduction training changed number of sexual partners but not immune function in men with HIV. Am J Public Health 1989;79:885–887.
16.Stead L, Lancaster T. Group behaviour therapy programmes for smoking cessation. The Cochrane Database of Systematic Reviews 2003;1.
17.Brown SA, Garcia AA, Kouzekanani K, Hanis CL. Culturally competent diabetes self-management education for Mexican Americans: the Starr County border health initiative. Diabetes Care 2002;25:259–268.
18.Classen C, Butler LD, Koopman C, et al. Supportive-expressive group therapy and distress in patients with metastatic breast cancer: a randomized clinical intervention trial. Arch Gen Psychiatry 2001;58:494–501.
19.Morse G. Positively reframing perceptions of the menstrual cycle among women with premenstrual syndrome. J Obstet Gynecol Neonatal Nurs 1999;28:165–174.
20.Shain RN, Champion JD, Perdue S, et al. Behavioral intervention to prevent sexually transmitted disease and pregnancy. World Congress of Pediatric and Adolescent Gynecology. Helsinki, Finland; 1998.
21.Shain RN, Perdue ST, Piper JM, et al. Behaviors changed by intervention are associated with reduced STD recurrence: the importance of context in measurement. Sex Transm Dis 2002;29:520–529.
22.Shain RN, Perdue ST, Piper JM, Holden AEC, Champion JD, Newton ER. Developing and validating complex behavioural outcome measures. In: Stephenson JM, Imrie J, Bonell C, eds. Effective sexual health interventions: issues in experimental evaluation. Oxford University Press; 2003.
23.Shain RN, Ramos R, Perdue ST, Newton ER. Project SAFE: An Intervention to Prevent STDs among Minority Women. Los Altos: Sociometrics; 2002.
24.Catania JA, Kegeles SM, Coates TJ. Towards an understanding of risk behavior: an AIDS risk reduction model (ARRM). Health Educ Q 1990;17:53–72.
25.Ramos R, Shain RN, Johnson L. “Men I mess with don’t have anything to do with AIDS”: using ethno-theory to understand sexual risk perception. Sociol Q 1995;36:483–504.
26.Warner L, Newman DR, Austin HD, et al. Condom effectiveness for reducing transmission of gonorrhea and chlamydia: the importance of assessing partner infection status. Am J Epidemiol 2004;159:242–251.
27.Fishbein M, Jarvis B. Failure to find a behavioral surrogate for STD incidence–what does it really mean? Sex Transm Dis 2000;27:452–455.
28.Marx R, Aral SO, Rolfs RT, Sterk CE, Kahn JG. Crack, sex, and STD. Sex Transm Dis 1991;18:92–101.
29.Ross MW, Hwang LY, Zack C, Bull L, Williams ML. Sexual risk behaviours and STIs in drug abuse treatment populations whose drug of choice is crack cocaine. Int J STD AIDS 2002;13:769–774.
30.Fullilove RE, Fullilove MT, Bowser BP, Gross SA. Risk of sexually transmitted disease among black adolescent crack users in Oakland and San Francisco, California. JAMA 1990 263:851–855.
31.Hwang LY, Ross MW, Zack C, Bull L, Rickman K, Holleman M. Prevalence of sexually transmitted infections and associated risk factors among populations of drug abusers. Clin Infect Dis 2000;31:920–926.
32.Kalichman S, Carey M, Johnson B. Prevention of sexually transmitted HIV infection: a meta-analytic review of the behavioral outcome literature. Ann Behav Med 1996;18:6–15.
33.Schachter J. Biologic versus behavioral endpoints–the duet continues. Sex Transm Dis 2000;27:456–457.
34.Pequegnat W, Fishbein M, Celentano D, et al. NIMH/APPC workgroup on behavioral and biological outcomes in HIV/STD prevention studies: a position statement. Sex Transm Dis 2000;27:127–132.
35.Schoenborn C, Adams P. Alcohol Use Among Adults: United States, 1997–98, Advance Data 324. Atlanta: CDC; 2001.
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