The investigators propose a highly efficient four-arm (factorial) trial to simultaneously test the efficacy of two behavioral interventions aimed at: * increasing condom use in the context of ongoing drug use and * decreasing needle and paraphernalia sharing among female sex workers who also inject drugs in two Mexican-U.S. border cities: Tijuana and Ciudad Juarez.
Our specific aims are: * Aim 1: To evaluate the efficacy of a behavioral intervention to decrease sharing of syringes and injection paraphernalia among FSW-IDUs. We hypothesize that FSW-IDUs in the active experimental injection risk reduction condition will report: (a) less receptive and distributive needle sharing; (b) less sharing of injection paraphernalia; (c) obtaining syringes and injection paraphernalia from safer sources. * Aim 2: To evaluate the efficacy of a behavioral intervention to increase condom use among FSW-IDUs in the context of ongoing drug use. We hypothesize that FSW-IDUs in the active experimental sexual risk reduction condition will: (a) report less unprotected vaginal and anal sex; and (b) have fewer incident cases of specific STIs. * Aim 3: To evaluate the joint effects of these two behavioral interventions to increase condom use and reduce sharing of needles and syringes/injection paraphernalia among FSW-IDUs. We hypothesize that the joint effect of these interventions will generate greater risk reductions compared to either intervention alone. * Aim 4: To determine the extent to which theoretically-important components of our interventions (i.e., self-efficacy, outcome expectancies, attitudes, intentions) represent underlying mechanisms of change in primary outcomes (i.e., sexual- and injection-related risk reductions). * Aim 5: To explore subgroup differences in the efficacy of: a) the sexual risk reduction, and b) the injection risk reduction intervention based on background characteristics, contextual factors, social factors and intrapersonal factors.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
PREVENTION
Masking
DOUBLE
Enrollment
584
This is a one-on-one intervention that incorporates elements of motivational interviewing (MI) and principles of Social Cognitive Theory (SCT) and Theory of Reasoned Action (TRA) to address the context of both, a) unsafe injection sharing and the extent to which syringes and other injection paraphernalia is shared; and b) unsafe sex and condom use with clients, and associated risks (e.g., HIV (Human Immuno-deficiency Virus), STIs (Sexually Transmitted Infections), pregnancy).
This is a one-on-one intervention that incorporates elements of motivational interviewing (MI) and principles of Social Cognitive Theory (SCT) and Theory of Reasoned Action (TRA) to address the context of unsafe sex and condom use with clients, and associated risks (e.g., HIV (Human Immuno-deficiency Virus), STIs (Sexually Transmitted Infections), pregnancy).
Sadec-Femap
Ciudad Juárez, Chihuahua, Mexico
PrevenCasa, AC
Tijuana, Estado de Baja California, Mexico
Combined HIV/STI 12-month Incidence Rates of HIV, Syphilis, Chlamydia, Gonorrhea and Trichomonas Vaginalis.
Combined incidence for HIV/STI was calculated over the 12-month study period and included only those who a) had at least one follow-up visit and b) at baseline tested negative for HIV and any of the aforementioned STIs. In the calculations we accounted for the time each participant spent at risk of HIV/any STI during the follow-up period, by using available information on each participant for each time point (i.e. baseline, 4-, 8-, and 12-months was used). The analytic method used for this outcome analysis was Poisson regression with robust variance estimation. The outcome variable was a binary variable indicating whether a participant has contracted HIV or a new STI during the 12-month follow-up period. The primary factor of interest was the intervention group. The log ("time spent at risk of HIV/any STI") was used as an offset variable in order to account for the time spent at risk of HIV/any STI by each participant.
Time frame: 12 months, with measuring points at baseline and at 4, 8, and 12 months past baseline
Change (Baseline to 4-, 8-, and 12-months) in the Mean Number of Unprotected Sex Acts With Clients.
The analytic method used for a) was negative binomial regression with the number of unprotected sex acts with clients as the outcome variable and intervention group, time point (baseline, 4-, 8-, and 12-months), and the interaction between the two as the main effects of interest.
Time frame: 12 months, with measuring points at baseline and at 4, 8, and 12 months past baseline
Change (Baseline to 4-, 8-, and 12-months) in the Proportional Odds of Higher Receptive Needle Sharing
For a) we asked: "In the past month, how often have you used a needle or syringe that you knew or suspected had been used before by someone else?" (possible responses: 1=never, 2=sometimes, 3=about half the time, 4=often, 5=always), with a higher response indicating a higher risk. The intervention effect was evaluated by conducting ordinal logistic regression, with the frequency of receptive needle sharing as the outcome variable and Group (Intervention vs. Control), Visit (Baseline, 4-months, 8-months, and 12-months) and the interaction term between the two (Visit\*Group) as the main effects. Our primary interest was the Visit\*Group interaction, with a significant corresponding p-value being indicative of an intervention effect.
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This is a one-on-one intervention that incorporates elements of motivational interviewing (MI) and principles of Social Cognitive Theory (SCT) and Theory of Reasoned Action (TRA) to address the context of unsafe injection sharing and the extent to which syringes and other injection paraphernalia is shared.
60 minute lecture-format presentation on safer sex and safer injection based on CDC guidelines for HIV counseling, testing, and referral and materials from Mexico's National Center for AIDS Studies (CENSIDA). There are no theory-driven active skill building elements oriented towards safer sex or safer injection.
Time frame: 12 months, with measuring points at baseline and at 4, 8, and 12 months past baseline
Change (Baseline to 4-, 8-, and 12-months) in the Mean Score of the Injection Risk Index (IRI).
The injection risk index (IRI) was calculated by averaging the responses to the following five questions: 1. In the past month, how often have you used a needle or syringe that you knew or suspected had been used before by someone else? 2. In the past month, how often was a new syringe used to divide the drug? 3. In the past month, how often did you use a bottle-cap/spoon/cooker after someone else had used it? 4. In the past month, how often did you use a cotton filter for a needle after someone else had used it? 5. In the past month, how often did you use rinse water to clean needles after someone else had used it? The possible responses to the questions were coded as follows: 0=never, 1=sometimes, 2=about half the time, 3=often, 4=always. Before averaging the responses to the five questions, the responses to the second question were reversed coded to yield the same direction as the responses to the other four questions. IRI range: 0-20. Higher IRI--\>higher risk.
Time frame: 12 months, with measuring points at baseline and at 4, 8, and 12 months past baseline