Elsevier

Contemporary Clinical Trials

Volume 28, Issue 5, September 2007, Pages 626-637
Contemporary Clinical Trials

Design of a stage-matched intervention trial to increase dual method contraceptive use (Project PROTECT)

https://doi.org/10.1016/j.cct.2007.01.012Get rights and content

Abstract

This manuscript describes the randomized clinical trial titled Stage-Matched Intervention to Increase Dual Method Use or Project PROTECT. Project PROTECT compared two approaches to promote the use of dual methods of contraception among high-risk women. The intervention arm received tailored individualized feedback based on the Transtheoretical Model of Behavior Change using a computer-based multimedia program. The control arm received general information on contraception. The primary outcomes of this trial were 1) self-reported use of dual methods of contraception and 2) the biological outcomes of an unintended pregnancy or an incident or recurrent sexually transmitted disease. In this report, we describe the significance and background of the problem, the specific aims of the study, study organization, patient selection, randomization, outcome variables, data collection, procedures used for follow-up and testing, primary and secondary outcomes, and statistical analyses. We also describe participant characteristics and procedures used to assure patient safety and trial monitoring.

Introduction

Unintended pregnancy, sexually transmitted diseases (STDs), and the adverse health consequences of STDs are widespread public health problems in the United States and worldwide. Between 1995 and 2000, at least 338 million pregnancies were unintended or unwanted worldwide [1], [2]. In addition, 340 million cases of STDs occur annually [3]. Young women, especially young women of color, are disproportionately affected by STDs, HIV/AIDS, and unintended pregnancy [4], [5].

Encouraging the correct and consistent use of effective contraceptive methods is a main approach to the prevention of both unintended pregnancy and STDs. Recent patterns of contraceptive use in the U.S. have been encouraging. Since 1982 the overall contraception coverage has increased by approximately 10%, almost all sexually active women have used contraception at some point, and 79% of women reported contraceptive use at their first intercourse [6]. This increase in contraceptive use has contributed to declines in unintended and unplanned pregnancies [7]. The predominant forms of contraception in the U.S., sterilization and oral contraceptives, are highly effective at preventing pregnancy [8]. Unfortunately, contraceptive methods with the highest efficacy for prevention of pregnancy (hormonal contraceptives, sterilization, and the intrauterine device (IUD)) provide no protection against STDs. Barrier contraceptive methods (specifically male condoms), when used consistently and correctly, can provide effective prevention of STDs, but are associated with relatively higher pregnancy rates than other contraceptive methods [9], [10].

The concept of “dual methods” of contraception involves the use of both a method that is highly effective at pregnancy prevention coupled with one that is highly effective at prevention of STDs (e.g. barrier method). Existing data indicate that the use of dual methods is not common. Among a cohort of women at high-risk for HIV, only 20% reported dual method use [11]. According to goals set forward in Healthy People 2010, the target is to have at least 9% of sexually active 15–17 year-old females using a condom plus a hormonal method at 1st intercourse, and at least 11% using dual methods at last intercourse [12]. Recent reported trends in dual method use are encouraging. In 1995, 7% of 15–17 year-old adolescents reported the use of condoms and a hormonal method at last intercourse compared to 24% in 2002 [12]. Finally, understanding the benefits of dual method use is essential for those counseling women on contraceptive use — as previous studies have shown that condom use is less likely in women using oral contraceptives [8], [13]. A study of women initiating hormonal contraceptive use found that the proportion using condoms fell from 21% to 11% [14].

Although there is some evidence that the proportion of women using dual methods in certain populations may be increasing, [15], [16], [17] relatively little is known about factors that promote or inhibit dual method use. In fact, little is known about the prevalence of consistent dual protection among those at high-risk for both pregnancy and STDs. Population- and clinic-based studies have found that women requesting contraception are not always prepared to use it. Evidence suggests that many women have little intention of using requested contraception or may only be considering using it at some point in the future [18]. Even in clinical settings, sexually active, at-risk women have been found to be at very different stages of readiness to use even one form of contraception consistently.

The “dual method” concept has been met with a number of challenges and obstacles [19], [20]. One dilemma for clinicians is whether to advocate for the consistent and correct use of condoms as a primary method to prevent both unplanned pregnancy and STDs or to encourage the use of two different forms of contraception (e.g. hormonal method plus a barrier) to assure more comprehensive protection against these outcomes. There is a general lack of agreement on which approach is best, and few, if any, randomized trials supporting specific intervention approaches.

The primary purpose of Project PROTECT was to compare an individualized intervention designed specifically to encourage young women to use dual methods of contraception to an enhanced standard care (control). The intervention was a computer assisted, tailored, interactive intervention based on the Transtheoretical model (TTM) of behavior change. The control arm provides computer-based, non-tailored information regarding the use of contraceptive methods. This paper describes the design and methodology of the Project PROTECT trial including specific aims, study organization, patient selection, inclusion and exclusion criteria, randomization, details of the intervention arms, procedures employed, data collected, adherence, follow-up, the measurement of primary and secondary outcomes, and the statistical methods used. We will also present a preliminary descriptive analysis of the cohort.

Section snippets

Specific aims & hypotheses

The primary specific aims of Project PROTECT were to: 1) modify and adapt an existing computer-assisted, TTM-tailored, individualized intervention to increase dual method use; and 2) evaluate the efficacy of the intervention compared to control in increasing dual method use and decreasing incident STD and unintended pregnancy. The primary hypotheses of this trial were that: 1) the intervention will result in a greater increase in dual contraceptive use than the standard care approach; and 2)

Design and outcomes

Project PROTECT was a randomized clinical trial funded by the National Institute of Child Health and Human Development (NICHD) at the National Institutes of Health. The primary behavioral outcome was dual method contraceptive use. The most common form of “dual method use” includes the use of a condom for STD protection and another form of contraception that increases the contraceptive effectiveness (e.g. hormonal method, sterilization). We modified an existing intervention to promote condom

Sample size

Sample size projections were based on two primary endpoints: 1) a two-fold increase in dual method use from approximately 15% to 30% (relative risk (RR) of the intervention equals 2.0 compared to control), and 2) a 50% difference in incidence of an STD or unintended pregnancy (RR of intervention equals 0.5 compared to control). The operating characteristics of both hypothesis tests are 2.5% type I error rate and 90% power. We chose the 2.5% critical level within each test because with two

Study coordination

Investigators at the Division of Research at Women & Infants Hospital were responsible for overall study coordination, recruitment, data collection and management, quality assurance, and preliminary analysis of study data. Each center had a study coordinator, and research and clinical staff qualified to recruit, counsel, examine, diagnose, and treat women for STDs. Investigators at the Cancer Prevention Research Center at the University of Rhode Island were primarily responsible for

Study sites

Women & Infants Hospital in Providence, RI was the primary site for participant recruitment. When the study was initiated, a second site in the Providence area, Memorial Hospital, was actively recruiting patients. In year 2 of recruitment, the principal investigator at the Memorial Hospital site was relocated to a different institution. After careful consideration and investigation, it was determined that recruitment and follow-up at the Memorial site could no longer be performed with adequate

Participant recruitment

Participants were recruited from primary care, gynecology, and family planning clinics at the two hospitals involved in the study, as well as from Planned Parenthood of Rhode Island. Advertisement was done in local city and university newspapers, on local cable and radio stations, and nurse recruiters visited local high schools and colleges in the Providence area. During the study we also initiated a “refer-2-friends” program (a.k.a. snowballing) to encourage and improve recruitment of

Patient selection and eligibility

Subjects recruited for this trial were eligible if they were English speaking and between the ages of 13 to 35. Our initial participant inclusion criteria limited enrollment to women aged 18 to 35 years. After being requested on numerous occasions by parents to enroll their daughter(s) in this project we obtained Institutional Review Board (IRB) approval and modified the study protocol to include a lower age limit of 13 years. Parental consent and minor assent were obtained for all participants

Baseline procedures and data collection

The initial interview included a baseline questionnaire and a pelvic examination. The baseline questionnaire included questions about sociodemographic characteristics (e.g. insurance coverage, race/ethnicity, etc.), substance abuse, domestic violence, levels of stress, sexual history, history of STDs, current contraceptive use, and plans for future contraceptive use. The pelvic examination included an evaluation of the external genitalia, vagina and cervix and was performed by a study clinician

Randomization

An interactive computer program collected the necessary baseline information from each participant and allocated patients to a study arm. Randomization was stratified by study site and by baseline contraceptive group (none/inconsistent use, barrier method, hormonal contraception, and other) in an attempt to balance each of the site/group strata. The randomization was 1:1 within site and within strata to force balance within each recruitment site. The computer was separated from the executor of

Intervention

All participants completed parts of their initial assessment using a computer. Computer-based assessment has been demonstrated to increase honest responding, especially for sensitive questions [24]. Participants were randomized to one of two computer-based intervention arms: the intervention or the control arm. Participants were carefully counseled regarding the use of the computer keyboard and mouse, and assistance was available on-site for participants who required additional help. The

Control arm

The control or comparison group received “enhanced standard care.” This intervention included generic computer-based contraceptive information and advice. The participant chose which method they would like to learn more about from a menu, and the computer provided information about each method. The intervention was neither individualized nor tailored in any way. In addition to the computer-based intervention, all participants received non-tailored educational materials (e.g. pamphlets). The

Follow-up procedures and data collection

Follow-up activities included maintenance of a contact sheet, with routine lists of patients drawn off the database to re-establish contact at the 6, 12, 18 and 24-month timeframes. If a subject could not be reached at their primary residence or any of their other contact phone numbers, a letter was sent to the patient with a reminder about the study and a request to contact the study center. Scheduled visits at 12 and 24 months were planned during the 6 and 18-month interviews. We sent a

Behavioral outcomes

The primary behavioral outcome in this study was self-reported use of dual methods of contraception at any time after randomization. We defined dual contraceptive use as one of the following: 1) use of hormonal contraception (e.g. oral contraceptives, estrogen–progesterone injections (Lunelle) long-acting progestin injections (Depo-Provera), etc.) plus a barrier method (e.g. male or female condoms or diaphragm); 2) male condoms plus female condoms; 3) condoms plus spermicide; or 4) intrauterine

Data management

In order to establish efficient and valid data management, we designed user-friendly data collection forms for both those completing the forms and for those performing the computer data entry. A manual of procedures was developed by the Women & Infants team in consultation with the collaborators at University of Rhode Island, Memorial Hospital, and Brown University. This manual served as a reference and training manual and documents protocols for recruitment, treatment, data collection, and

Baseline results

From October 1999 to October 2003, 542 women were recruited into Project PROTECT. Fig. 1 is a flow diagram to illustrate the number of participants screened, excluded, eligible, and randomized. Of the 1112 women screened, 924 were initially considered eligible. Eight of the initially eligible women were later excluded from the study: six due to an unrecognized pregnancy at baseline, 1 due to inability to verify age, and 1 due to inability to verify consent, resulting in 916 eligible subjects.

Discussion

The study protocol went through many rigorous reviews prior to study inception; however, several minor changes were decided upon as the trial progressed. These changes had operational considerations and included issues such as accepting a serologic test for syphilis (RPR) result within 9 months of randomization rather than the originally stated 6 months due to the low likelihood of conversion and redundant expense. A number of items and forms were added to the participant records, and

Acknowledgement

The authors wish to acknowledge important contributions from Joseph Hogan at Brown University Center for Statistical Sciences.

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    Supported by National Institutes of Health grant 1RO1-HD36663-01, Stage-Matched Intervention to Increase Dual Method Use, from the National Institutes of Child Health and Human Development. Also supported in part by National Institutes of Health grant K24 HD01298-03, Midcareer Investigator Award in Women's Health Research from the National Institutes of Child Health and Human Development.

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