Retrospective versus prospective estimates of number of sexual partners

Assessment of changes in condom use among female sex workers in a prospective cohort study introducing diaphragm use for disease prevention

Changes in the rates of condom use and number of sexual partners were evaluated among 140 female sex workers in Kibera, Kenya, participating in a 6-month study of diaphragm safety and acceptability for prevention of sexually transmitted infections conducted in 2004-2005. Analyses were stratified by partner type. Multivariable Tobit regression modeling was used to assess the association between study visit and proportion of acts protected. Participants completed 140 baseline visits and 390 bimonthly follow-up visits. The mean percentage of coital acts reported as protected by a condom increased from 56% at baseline to 68% at the 6-month visit (P < 0.01). Similar increases were observed for condom use by all partner types. Additionally, the mean number of sexual partners decreased over the study. Furthermore, consistent (i.e., 100%) diaphragm use during follow-up was associated with a higher proportion of coital acts protected by a condom in analyses adjusted for study visit and coital frequency. These findings suggest that, despite concerns that introduction of the diaphragm would result in more risky sexual behaviors, reported condom use increased and number of partners decreased.

Contraceptive use and discontinuation: findings from the contraceptive history, initiation, and choice study

OBJECTIVE

The purpose of this study is to provide insight on the continuing high rate of unintended pregnancy among adult women.

STUDY DESIGN

Contracepting women were recruited while they waited for primary care appointments. A total of 369 completed the baseline questionnaire, and 145 oral contraceptive (OC) users were enrolled in a 5-week, diary-based study of adherence and sexual activity.

RESULTS

Most women who reported having discontinued OCs did so because of medical side effects, and most had switched to less effective methods. Among OC users, 26.4% had sexual intercourse on days they missed pills just before or after their placebo week. Nonadherence did not differ by socioeconomic factors or obesity.

CONCLUSION

Clinicians may need to encourage their patients to discuss their reasons for wanting to discontinue the use of an effective contraceptive method and assist them with their concerns or to switch to other effective methods to protect themselves from unintended pregnancy.

Rectal use of nonoxynol-9 among men who have sex with men

OBJECTIVES

To assess recent rectal use of nonoxynol-9 (N-9), intent to use the product, and factors associated with N-9 use among men who have sex with men (MSM).

DESIGN

Cross-sectional survey of a diverse sample of MSM in the San Francisco Bay Area.

METHODS

Recruitment conducted at multiple street locations on various days/times or through referral during the Fall of 2001.

RESULTS

Sixty-one percent (349/573) had heard of N-9, of which 55% (192/349) reported hearing in the prior year that N-9 may not be protective against HIV. Of men aware of N-9, 83% (289/349) knowingly used it in their lifetime, of which 67% (193/289) used it during anal intercourse in the previous year. Forty-one percent (79/193) of those who used N-9 during anal intercourse in the past year did so without a condom because they thought it may protect against HIV. Older men were more likely than younger men to have used N-9 for protection. Men who heard that N-9 may not protect were less likely, and African-Americans (versus Caucasians) were more likely, to say they would definitely use N-9 during anal intercourse in the future. Latinos (versus Caucasians), those with unknown HIV serostatus (versus HIV-negative), and those with lower education were less likely to know about N-9 at all, and thus were at risk for unknowingly using N-9.

CONCLUSIONS

Many MSM used N-9 during or following public health warnings about the product. Actions (e.g., information campaigns, warning labels specific to rectal use) should be considered by communities to reduce rectal use of N-9.

A statistical model for the evaluation of barrier contraceptive efficacy

This paper describes an approach for the analysis of barrier contraceptive efficacy trials that accounts for timing frequency of intercourse and compliance. We allow exposure variables to vary for each act of intercourse and we control for timing of each act through a specific parametric function of the day of the act relative to the last day of the follicular phase of the cycle. The model can be used to examine the level of protection provided by a barrier versus no contraceptive method even when no control group of non-users is studied, as long as there are acts with no barrier use during the fertile window. We present results of a simulation study which examines performance of estimators and power under a variety of scenarios, including situations where an accurate benchmark for ovulation day is not available. As compared to the survival analysis approach commonly used in this setting, simulation results show that the new approach yields considerable gains in power to detect differences between the efficacy of contraceptive methods. An application to data from the FemCap versus diaphragm trial show results consistent with previous findings suggesting superiority of the diaphragm but also provides new evidence of the per act protection provided by both methods.

Are condoms effective in reducing the risk of sexually transmitted disease?

A panel of more than two dozen experts reviewed the scientific evidence on condom effectiveness for sexually transmitted disease (STD) prevention, and a final report was released July 20, 2001, by the Department of Health and Human Services. This panel was cosponsored and convened for a two-day workshop by four government agencies (Agency for International Development, Food and Drug Administration, Centers for Disease Control and Prevention [CDC], and the National Institutes of Health [NIH]).

Retrospective vs. prospective coital frequency and menstrual cycle length in a contraceptive effectiveness trial

PURPOSE

To determine how well information at enrollment would predict coital frequency and menstrual segment length during a prospective contraceptive effectiveness trial.

METHODS

We compared retrospective reports of monthly coital frequency and menstrual segment (cycle) length with prospective information for women participating in a contraceptive trial of the Reality((R)) female condom.

RESULTS

Participants reported slightly higher mean monthly coital frequency and slightly longer menstrual segments prior to the study than during the study (12.6 acts vs. 12.0 acts per month and 30.8 days vs. 28.4 days). We examined the actual distribution of differences between the retrospective and prospective measures and found considerable variability. Among the 195 participants studied, parous women were less likely to predict accurately menstrual segment length (OR 0.4; 95% CI 0.3--0.9), while older women were more likely to predict accurately coital frequency (OR 1.9; 95% CI 0.9--3.3).

CONCLUSIONS

Coital frequency and menstrual segment length vary considerably over time. Hence, prospective data collection is essential to accurately characterize these variations and to properly interpret results from contraceptive trials and other studies concerned with fecundability and hazards of reproduction.

Thermoreversible gel as a candidate barrier to prevent the transmission of HIV-1 and herpes simplex virus type 2

BACKGROUND

Sexually transmitted diseases (STDs) caused by HIV, herpes simplex virus (HSV), and other pathogens are spreading dramatically. The need to develop active products and vehicles to reduce this epidemic is urgent.

GOAL

The efficacy of a thermoreversible gel formulation as a possible barrier to prevent the transmission of pathogens causing STDs was evaluated.

STUDY DESIGN

This evaluation investigated the ability of the gel formulation to prevent infection of susceptible cells by HIV-1 and HSV-2 in vitro, the diffusion of radiolabeled herpes virus and micelles of polymer through an insertion membrane, and the electron microscopic appearance of herpes virus and gel alone or mixed together.

RESULTS

The gel formulation prevents infection of susceptible cells by HIV-1 and HSV-2. It acts as an effective artificial physical barrier against the herpes virus within the first 4 hours of incubation. Herpes virus is coated by the gel or entrapped within micelles of the gel, which could hinder its attachment to target cells and inhibit its infectivity.

CONCLUSION

This thermoreversible gel formulation represents an attractive matrix for the incorporation of microbicides to prevent the spread of STDs.

Awareness and use of untested barrier methods by HIV-seropositive gay and bisexual men

Little is known about HIV-seropositive men's awareness and use of untested barrier methods during anal intercourse. A sample of 240 HIV-seropositive men (69.2% men of color) completed a self-administered survey that included items on nonoxynol-9 (N-9), female condoms, and the simultaneous use of two male condoms (double bagging). Most participants (79.6%) had heard of N-9 being used to prevent HIV transmission during anal intercourse. Of these, 20.0% rated N-9 as more effective than condoms, and 14.6% had used N-9 instead of condoms. Fewer men (35.4%) were aware of female condoms being used during anal intercourse. Overall, few respondents (5.4%) had used female condoms; 53.8% of whom rated the device as more pleasurable than male condoms. Most men (69.6%) had heard of double bagging, and 35.2% had engaged in this practice. Of these, 45.1% rated the practice as less pleasurable than using a single condom. Few associations were observed between participant characteristics and the awareness or use of these barrier methods. The widespread use of these untested methods emphasizes the urgent need to further educate HIV-seropositive men about the potential risks of N-9 use and to test the effectiveness of other strategies that may serve as alternatives to male condom use.

A comparison of three daily coital diary designs and a phone-in regimen

Barrier contraceptive trials and disease intervention studies often utilize coital diaries to measure sexual exposures: dates and frequency of intercourse, product use, additional or alternative contraceptive use, and menstrual bleeding. The validity of these self-reported data is a matter of debate, but if used, better diary designs are sought. We studied 3 different coital diaries, plus a phone-in regimen (none or weekly) in a 3 x 2 factorial design to compare participant ratings and promptness of recording. Our underlying presumption was that ease of and satisfaction with use, and promptness of data collection, are associated with greater accuracy. A self-completed questionnaire at the end of the study collected comparative retrospective data. Diary 1 captured information about a single day on one page and had three columns, for up to three possible acts of intercourse. Diary 2 had the same question format as the first diary, but contained 7 days per page. Diary 3 had 7 days on a page, but instead of a column for each act, participants enumerated the number of acts, the types of contraception used, and condom use details. Half of the women in each diary group phoned in their data weekly. Phone-in improved participants' satisfaction with the diary design as reflected by higher ratings of diary features. Phone-in did not improve recall of data at the end of the study for any of the diaries. There were no differences in the promptness of diary completion. Diaries 1 and 2 showed good concordance with recalled data, and participants expressed a preference for the layout of Diary 2. Women assigned to Diary 3 expressed dissatisfaction with the design and were worse at recalling data at the end of the study, probably due to the complexity of that diary design.

Condom use in young blacks and Hispanics in public STD clinics

BACKGROUND AND OBJECTIVES

Young blacks and Hispanics are an emerging risk group for contracting HIV. The goal of this study was to assess the most salient correlates of condom use for young Hispanics and blacks in Los Angeles county sexually transmitted diseases (STD) clinics as a first step toward designing a short clinic-based intervention.

STUDY DESIGN

Face-to-face interviews were conducted with 376 patients younger than the age of 27 years at six STD clinics operated by the Los Angeles County Department of Health Services. Assessment included several attitudinal variables and AIDS risk behaviors.

RESULTS

Condom use at last intercourse ranged from 40% among Hispanic females to 48% among black males. Among females, condom users were more likely to report high self-efficacy regarding condom use, peer norms supporting condom use, and more sexual communication than respondents who did not use a condom at last intercourse. Among males, no relationship was found between condom use at last intercourse and these attitudinal variables, except for sexual communication. The most important correlate of condom use among males and females was the frequency of carrying condoms.

CONCLUSIONS

Our findings suggest that offering educational group sessions and attractive means for carrying condoms to patients in STD clinics may have the potential to increase condom use. The efficacy of these intervention strategies should be explored in future studies.

Factors predicting upper genital tract inflammation among women with lower genital tract infection

We sought to identify factors that discriminate between women with a lower genital tract infection and women with a lower genital tract infection and endometritis. This study enrolled women at risk for or having a lower genital tract infection with Chlamydia trachomatis or Neisseria gonorrhoeae and measured behavioral and clinical factors. Women were identified through contact tracing of male partners, presentation with cervicitis, or presentation with symptoms of pelvic inflammatory disease and classified as (1) having a lower genital tract infection without endometritis, (2) having a lower genital tract infection with endometritis, (3) having no lower genital tract infection with endometritis, and (4) having neither a lower genital tract infection nor endometritis. The primary comparison was between women having a lower genital tract infection without endometritis to women having a lower genital tract infection and endometritis. Women with a lower genital tract infection and endometritis were older and reported a history of more sexually transmitted diseases (70.0% vs. 56.7%), abdominal pain (82.2% vs. 60.0%), and use of barrier methods of contraception (28.9% vs. 8.6%) than women with a lower genital tract infection alone. The regression model found that women with a lower genital tract infection and endometritis were 7.1 times (95% CI = 2.2-23.0) more likely to report abdominal pain and 4.6 times (95% CI = 1.5-14.9) more likely to use barrier methods of contraception than women with a lower genital tract infection alone. These results suggest that behavioral factors, in addition to symptoms, can be used to identify women with and without upper genital tract involvement.

Objective markers of condom failure

BACKGROUND

Studies of condom efficacy rely on self-reported behavior. Objective markers of exposure to semen may provide a more valid assessment of condom failure and failure to use condoms.

GOALS OF THIS STUDY

To compare three semen biomarkers: acid phosphatase (AP) activity, prostate specific antigen (PSA), and the human seminal plasma antigen (MHS-5).

STUDY DESIGN

Twenty women were intravaginally inoculated with six measured, increasingly larger amounts of their partners' semen. Vaginal fluid was collected by the participant using swabs and tested.

RESULTS

Background levels of PSA were low (0.00-1.25 ng/ml), background levels of AP were variable (0-350 U/l), and all preinoculation samples were negative for MHS-5. All postinoculation samples were positive for PSA, 64 of 117 (55%) for AP, and 14 of 120 (12%) for MHS-5.

CONCLUSION

The PSA immunoassay was the best semen biomarker under these sampling and testing conditions.

Long-term use of the female condom among couples at high risk of human immunodeficiency virus infection in Zambia

BACKGROUND

Few studies have measured female condom use for more than a 6-month period or among persons at high risk of STD.

OBJECTIVE

To measure long-term use of the female condom among couples at high risk of HIV infection and to evaluate the effect of female condom use on unprotected coital acts.

STUDY DESIGN

Ninety-nine Zambian couples with symptomatic sexually transmitted diseases (STD) received female condoms, male condoms, and spermicides and were counseled to use either condom plus spermicide for each coital act. Couples were followed up at 3-, 6-, and 12-month visits. Barrier contraceptive use was measured prospectively by coital log.

RESULTS

Among the 99 couples enrolled, 51, 38, and 30 couples were successfully followed up for 3, 6, and 12 months, respectively. Female condoms were reportedly used in 24%, 27%, and 23% of coital acts and by 86%, 79%, and 67% of the returning couples during each time interval. Higher-level female condom users used male condoms less often but had fewer unprotected coital acts (5% vs. 14%; p < 0.05) than lower-level female condom users.

CONCLUSION

A majority of couples at high risk of HIV infection used the female condom in conjunction with other barrier methods over a 1-year period. The addition of female condoms accompanied by appropriate counseling to the barrier method mix may reduce unprotected sex among couples at high-risk of HIV infection.

Do spermicides containing nonoxynol-9 prevent sexually transmitted infections? A meta-analysis

BACKGROUND AND OBJECTIVES

There are conflicting opinions on whether to recommend spermicides containing nonoxynol-9 for prevention of sexually transmitted diseases, including human immunodeficiency virus (HIV).

GOAL

To systematically review and summarize the medical literature on the effect of spermicides containing nonoxynol-9 on prevention of gonorrhea, chlamydial infection, and HIV.

STUDY DESIGN

Meta-analysis. Potential articles were identified through computerized literature searches. Articles were included if the design was clinical trial, cohort, case-control, or cross-sectional; original outcome data were presented for gonorrhea, chlamydial infection, or HIV; and spermicides containing nonoxynol-9 were used separately from other barrier methods. Study characteristics including design, population, spermicide dose, and delivery method were abstracted. Relative risks (RR) and 95% confidence intervals (CI) were determined from information published in the study or from study authors. Summary risk estimates were computed for clinical trials.

RESULTS

Twelve eligible articles were identified, including six clinical trials and six observational studies. Eleven articles evaluated gonorrhea; each found a reduced risk of infection with spermicide use. Among six clinical trials, the summary RR was 0.62 (95% CI, 0.49-0.78). The five articles evaluating chlamydial infection also found significant reduction among spermicide users, with the four clinical trials having a summary RR of 0.75 (95% CI, 0.62-0.91). The degree of spermicidal protection against gonorrhea and chlamydial infection did not differ materially among studies with different study designs or spermicidal preparations (i.e., sponge, gel, suppository, or film). Three studies evaluated degree of protection according to consistency of use and found stronger protection with more consistent use. The two studies on spermicidal prevention of HIV had contrasting results: An observational study found a significant protective effect (RR = 0.1), whereas a clinical trial found a nonsignificantly increased risk (RR = 1.7).

CONCLUSIONS

Nonoxynol-9-containing spermicides have an appreciable protective effect against both gonorrhea and chlamydial infection, and wider use of spermicides might substantially reduce the incidence of these diseases. However, insufficient data exist to judge their effect on HIV transmission, and more research on the effect of nonoxynol-9 on HIV transmission is urgently needed to make evidence-based clinical decisions and public health recommendations in the future.

Use of spermicide and impact of prophylactic condom use among sex workers in Santa Fe de Bogota, Colombia

BACKGROUND AND OBJECTIVES

Condom use is one of the most important preventive measures sex workers can take to reduce the risk of becoming infected with a sexually transmitted disease. However, a client may refuse to use a condom when requested. Some sexually transmitted disease prevention programs are recommending that sex workers use spermicide as an alternative prophylaxis when a condom is refused, yet little is known about the effect of this recommendation on prophylactic condom use.

GOAL

To determine if using spermicide, either in conjunction with condoms or as a backup, influenced overall condom use among a group of sex workers at high risk of sexually transmitted diseases in Santa Fe de Bogota, Colombia.

STUDY DESIGN

Participants were assigned randomly to one of three condom use groups: use of condoms only (Condoms Only), use of condoms and spermicides concurrently (Condom and Spermicide), or use of spermicide when condoms were refused (Spermicide as a Backup). A total of 199 sex workers entered the study and were asked to return for follow-up every 2 weeks for a period of 12 weeks.

RESULTS

Women assigned to the Spermicide as a Backup group used a condom for an average of 78.1% of their reported acts of intercourse, compared with an average of 94.5% in the Condom Only and 92.3% in the Condom and Spermicide groups. However, women in the Spermicide as a Backup group used a condom or spermicide for an average of 96.9% of their acts of intercourse. Condoms were used for every intercourse act by less than 5% of the women in the Spermicide as a Backup groups, compared with 50.7% in the Condom Only group and 41.2% in the Condom and Spermicide group (P 0.001). When condoms were not used, client refusal was the primary reason reported. The incidence of sexually transmitted diseases and other urogenital inflammations in all groups was lower than expected.

CONCLUSIONS

Among Colombian sex workers, condom use declined substantially when women were instructed to use spermicides if they were unable to persuade their partner to use a condom. However, these same women usually used the study spermicide as an alternate prophylaxis.