Understanding risk: a randomized controlled trial of communicating contraceptive effectiveness

Knowledge of contraceptive effectiveness and method use among women in Hanoi, Vietnam

Objective

To evaluate the association between contraceptive knowledge and type of method used.

Methods

We analyzed data from a cross-sectional study of sexually active women in Hanoi, Vietnam, not desiring pregnancy. We used linear and logistic regression to evaluate contraceptive knowledge of users of the intrauterine device (IUD), combination oral contraception (COC) and male condoms. We measured contraceptive knowledge with seven questions on relative effectiveness of methods, reversibility, covert use, contraindications and side effects.

Results

Respondents used IUD (n = 128), COC (n = 126) or condoms (n = 167). Summary knowledge scores did not differ by current type of method used. Only one knowledge domain, contraceptive effectiveness, varied by method. Compared to condom users, IUD users had higher odds of correctly identifying the IUD as more effective than COC, condoms and withdrawal (adjusted odds ratio [aOR], 4.8; 95% confidence interval [CI], 2.7–8.3). Higher proportions of condom users (49.7%) mistakenly identified condoms as the most effective of listed methods compared to IUD (20.3%) and COC users (23.0%). On the other hand, IUD and COC users had lower odds (aOR, 0.5; 95% CI, 0.2–1.0 and aOR, 0.3; 95% CI, 0.1–0.6, respectively) of identifying consistent condom use as better for pregnancy prevention than other practices (e.g., withdrawal and postcoital douching).

Conclusions

IUD users more often recognized that the IUD is highly effective while condom users appeared to overestimate condom effectiveness. Contraceptive counseling should ensure that women understand the relative effectiveness of methods. We found no evidence that other types of contraceptive knowledge differed by type of method used.

Implications

Knowledge of contraceptive effectiveness was the sole difference detected in contraceptive knowledge between women in Hanoi, Vietnam, using the IUD, COC or male condoms.

Effects of Two Educational Posters on Contraceptive Knowledge and Intentions: A Randomized Controlled Trial

OBJECTIVE

To compare the Centers for Disease Control and Prevention's (CDC) contraceptive effectiveness poster with a more patient-centered poster on factors affecting the likelihood of using effective contraceptives.

METHODS

The posters were tested in a randomized controlled trial. Women were eligible if they were aged 18-44 years, could speak and read English, were not pregnant or trying to conceive, and had engaged in vaginal intercourse in the past 3 months. An online survey administered through Amazon Mechanical Turk was used to collect baseline and immediate follow-up data on three primary outcomes: contraceptive knowledge (measured using the Contraceptive Knowledge Assessment), perceived pregnancy risk, and the effectiveness of the contraceptive the woman intended to use in the next year. Subgroup analyses were conducted in women with prior pregnancy scares, low numeracy, and no current contraceptive. Within- and between-group differences were compared for the two randomized groups.

RESULTS

From January 26 to February 13, 2018, 2,930 people were screened and 990 randomized. For the primary outcomes, the only significant result was that the patient-centered poster produced a greater improvement in contraceptive knowledge than the CDC poster (P<.001). Relative to baseline, both posters significantly improved contraceptive knowledge (CDC +3.6, patient-centered +6.4 percentage points, P<.001) and a constructed score measuring the effectiveness of the contraceptive that women intended to use in the next year (CDC and patient-centered +3 percentage points, P<.01). This is equivalent to 1-17 of every 100 women who viewed a poster changing their intentions in favor of a more effective contraceptive.

CONCLUSION

This study suggests that both posters educate women about contraception and may reduce unplanned pregnancy risk by improving contraceptive intentions. Of the three primary outcomes, the patient-centered poster performs significantly better than the CDC poster at increasing contraceptive knowledge.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov, NCT03372369.

Cognitive interviews to improve a patient-centered contraceptive effectiveness poster

OBJECTIVES

To refine the Centers for Disease Control and Prevention (CDC)'s contraceptive education poster using patient-centered design.

STUDY DESIGN

We conducted cognitive interviews with 26 women aged 18-44 living in North Carolina who spoke and read English and had ever had sex. We interviewed women about both a CDC and a patient-centered poster in alternating order. Participants were contraceptive users and non-users that we selected purposively to have a range of characteristics that might influence their perspective: age, race/ethnicity, previous births and pregnancies, contraceptive method(s) used in the past three months, pregnancy intentions, and numeracy. The initial response rate for participants was 55%. We used cognitive theory to code interviews for comprehension, relevance, and acceptability, as well as design and overall preference. We structured the 26 interviews into four rounds and revised the patient-centered poster after each round to improve these measures.

RESULTS

By the final round, 83% of women preferred the patient-centered poster. The majority of women favored this poster's relevance (86%), and design (100%) and ease of comprehension (86%). Women raised few concerns about the acceptability of the final version of the patient-centered poster. Women identified many issues with both posters that the researchers did not anticipate, highlighting the value of patient-centered design approaches to educational materials.

CONCLUSIONS

This study refined a patient-centered poster so that its language is clear and it addresses the informational needs of its target audience.

IMPLICATIONS

The Centers for Disease Control and Prevention and the Office of Population Affairs recommend that clinicians educate women about contraception. This study developed a poster that could help clinicians follow this recommendation. Before widespread implementation, more research is needed to evaluate the poster's impact on contraceptive knowledge and behaviors.

Personalized contraceptive counseling: helping women make the right choice

Unintended pregnancy is a significant problem with medical, social, and economic consequences. Half of unintended pregnancies are a result of no contraceptive use; while the other half results from contraceptive inconsistencies, or method failure. Women have an array of contraceptive options to choose from, each of which differs significantly in terms of usage, efficacy, side effects, risks, and noncontraceptive benefits. Determining the best tool for communication is a challenge. In addition, the choice of contraceptive method differs among women with medical problems. Not all contraceptive methods are suitable for women with certain medical problems. In this review, we discuss different methods of counseling and the tools available for sharing contraception information.

Presenting Numeric Information with Percentages and Descriptive Risk Labels: A Randomized Trial

BACKGROUND

Previous research demonstrated that providing (v. not providing) numeric information about the adverse effects (AEs) of medications increased comprehension and willingness to use medication but left open the question about which numeric format is best. The objective was to determine which of 4 tested formats (percentage, frequency, percentage + risk label, frequency + risk label) maximizes comprehension and willingness to use medication across age and numeracy levels.

METHODS

In a cross-sectional internet survey (N = 368; American Life Panel, 15 May 2008 to 18 June 2008), respondents were presented with a hypothetical prescription medication for high cholesterol. AE likelihoods were described using 1 of 4 tested formats. Main outcome measures were risk comprehension (ability to identify AE likelihood from a table) and willingness to use the medication (7-point scale; not likely = 0, very likely = 6).

RESULTS

The percentage + risk label format resulted in the highest comprehension and willingness to use the medication compared with the other 3 formats (mean comprehension in percentage + risk label format = 95% v. mean across the other 3 formats = 81%; mean willingness = 3.3 v. 2.95, respectively). Comprehension differences between percentage and frequency formats were smaller among the less numerate. Willingness to use medication depended less on age and numeracy when labels were used. Generalizability is limited by the use of a sample that was older, more educated, and better off financially than national averages.

CONCLUSIONS

Providing numeric AE-likelihood information in a percentage format with risk labels is likely to increase risk comprehension and willingness to use a medication compared with other numeric formats.

WHO Tiered-Effectiveness Counseling Is Rights-Based Family Planning

Contraceptive effectiveness is the leading characteristic for most women when choosing a method, but they often are not well informed about effectiveness of methods. Because of the serious consequences of “misinformed choice,” counseling should proactively discuss the most effective methods—long-acting reversible contraceptives and permanent methods—using the WHO tiered-effectiveness model.

Impact of Contraceptive Education on Contraceptive Knowledge and Decision Making: A Systematic Review

CONTEXT

Educational interventions can help increase knowledge of available contraceptive methods, enabling individuals to make informed decisions and use contraception more effectively. This systematic review evaluated contraceptive education interventions to guide national recommendations on quality family planning services.

EVIDENCE ACQUISITION

Three databases (CINAHL, PubMed, and PsycINFO) were searched from 1985 through 2012 for peer-reviewed articles on educational interventions, with supplemental searches conducted through 2015. Primary outcomes were knowledge, participation in and comfort with decision making, and attitudes toward contraception. Secondary outcomes included contraceptive use behaviors and unintended pregnancy.

EVIDENCE SYNTHESIS

Database searches in 2011 identified 5,830 articles; 17 met inclusion criteria and were abstracted into evidence tables. Searches in 2012 and 2015 identified four additional studies. Studies used a wide range of tools (decision aids, written materials, audio/videotapes, and interactive games), with and without input from a healthcare provider or educator. Of 15 studies that examined the impact of educational interventions on knowledge, 14 found significant improvement using a range of tools, with and without input from a healthcare provider or educator. Fewer studies evaluated outcomes related to decision making, attitudes toward contraception, contraceptive use behaviors, or unintended pregnancy.

CONCLUSIONS

Results from this systematic review are consistent with evidence from the broader healthcare field suggesting that a range of educational interventions can increase knowledge. Future studies should assess what aspects of educational interventions are most effective, the extent to which it is necessary to include a healthcare provider or educator, and the extent to which educational interventions can impact behaviors.

Contraceptive counseling: best practices to ensure quality communication and enable effective contraceptive use

Improving the quality of contraceptive counseling is one strategy to prevent unintended pregnancy. We identify aspects of relational and task-oriented communication in family planning care that can assist providers in meeting their patients' needs. Approaches to optimizing women's experiences of contraceptive counseling include working to develop a close, trusting relationship with patients and using a shared decision-making approach that focuses on eliciting and responding to patient preferences. Providing counseling about side effects and using strategies to promote contraceptive continuation and adherence can also help optimize women's use of contraception.

Essential pre-pregnancy and pregnancy interventions for improved maternal, newborn and child health

The statistics related to pregnancy and its outcomes are staggering: annually, an estimated 250000-280000 women die during childbirth. Unfortunately, a large number of women receive little or no care during or before pregnancy. At a period of critical vulnerability, interventions can be effectively delivered to improve the health of women and their newborns and also to make their pregnancy safe. This paper reviews the interventions that are most effective during preconception and pregnancy period and synergistically improve maternal and neonatal outcomes. Among pre-pregnancy interventions, family planning and advocating pregnancies at appropriate intervals; prevention and management of sexually transmitted infections including HIV; and peri-conceptual folic-acid supplementation have shown significant impact on reducing maternal and neonatal morbidity and mortality. During pregnancy, interventions including antenatal care visit model; iron and folic acid supplementation; tetanus Immunisation; prevention and management of malaria; prevention and management of HIV and PMTCT; calcium for hypertension; anti-Platelet agents (low dose aspirin) for prevention of Pre-eclampsia; anti-hypertensives for treating severe hypertension; management of pregnancy-induced hypertension/eclampsia; external cephalic version for breech presentation at term (>36 weeks); management of preterm, premature rupture of membranes; management of unintended pregnancy; and home visits for women and children across the continuum of care have shown maximum impact on reducing the burden of maternal and newborn morbidity and mortality. All of the interventions summarized in this paper have the potential to improve maternal mortality rates and also contribute to better health care practices during preconception and periconception period.

Essential interventions: implementation strategies and proposed packages of care

In an effort to accelerate progress towards achieving Millennium Development Goal (MDG) 4 and 5, provision of essential reproductive, maternal, newborn and child health (RMNCH) interventions is being considered. Not only should a state-of-the-art approach be taken for services delivered to the mother, neonate and to the child, but services must also be deployed across the household to hospital continuum of care approach and in the form of packages. The paper proposed several packages for improved maternal, newborn and child health that can be delivered across RMNCH continuum of care. These packages include: supportive care package for women to promote awareness related to healthy pre-pregnancy and pregnancy interventions; nutritional support package for mother to improve supplementation of essential nutrients and micronutrients; antenatal care package to detect, treat and manage infectious and noninfectious diseases and promote immunization; high risk care package to manage preeclampsia and eclampsia in pregnancy; childbirth package to promote support during labor and importance of skilled birth attendance during labor; essential newborn care package to support healthy newborn care practices; and child health care package to prevent and manage infections. This paper further discussed the implementation strategies for employing these interventions at scale.

Numbers matter to informed patient choices: a randomized design across age and numeracy levels

BACKGROUND

How drug adverse events (AEs) are communicated in the United States may mislead consumers and result in low adherence. Requiring written information to include numeric AE-likelihood information might lessen these effects, but providing numbers may disadvantage less skilled populations. The objective was to determine risk comprehension and willingness to use a medication when presented with numeric or nonnumeric AE-likelihood information across age, numeracy, and cholesterol-lowering drug-use groups.

METHODS

In a cross-sectional Internet survey (N = 905; American Life Panel, 15 May 2008 to 18 June 2008), respondents were presented with a hypothetical prescription medication for high cholesterol. AE likelihoods were described using 1 of 6 formats (nonnumeric: consumer medication information (CMI)-like list, risk labels; numeric: percentage, frequency, risk labels + percentage, risk labels + frequency). Main outcome measures were risk comprehension (recoded to indicate presence/absence of risk overestimation and underestimation), willingness to use the medication (7-point scale; not likely = 0, very likely = 6), and main reason for willingness (chosen from 8 predefined reasons).

RESULTS

Individuals given nonnumeric information were more likely to overestimate risk, were less willing to take the medication, and gave different reasons than those provided numeric information across numeracy and age groups (e.g., among the less numerate, 69% and 18% overestimated risks in nonnumeric and numeric formats, respectively; among the more numerate, these same proportions were 66% and 6%). Less numerate middle-aged and older adults, however, showed less influence of numeric format on willingness to take the medication. It is unclear whether differences are clinically meaningful, although some differences are large.

CONCLUSIONS

Providing numeric AE-likelihood information (compared with nonnumeric) is likely to increase risk comprehension across numeracy and age levels. Its effects on uptake and adherence of prescribed drugs should be similar across the population, except perhaps in older, less numerate individuals.

Women's values in contraceptive choice: a systematic review of relevant attributes included in decision aids

BACKGROUND

Women can choose from a range of contraceptive methods that differ in important ways. Inadequate decision support may lead them to select a method that poorly fits their circumstances, leading to dissatisfaction, misuse, or nonuse. Decision support interventions, such as decision aids, may help women choose a method of contraception that best fits their personal circumstances. To guide future decision aid development, we aim to summarize the attributes of contraceptive methods included in available decision aids as well as surveys and interviews of women actively choosing a contraceptive method.

METHODS

We conducted a systematic review to identify attributes of contraceptive methods that may be important to women when engaging in this decision making process. We performed a database search of MEDLINE/PubMed, Ovid EMBASE, OVID CENTRAL, Ovid PsycInfo, EBSCO CINAHL, Popline, and Scopus from 1985 until 2013 to identify decision aids, structured interviews and questionnaires reporting attributes of contraceptive options that are of importance to women. A free-text internet search was also performed to identify additional decision support tools. All articles and tools were reviewed in duplicate for inclusion, and a summary list of attributes was compiled.

RESULTS

We included 20 surveys, 1 semistructured interview report and 19 decision aids, reporting 32 unique attributes. While some attributes were consistently included in surveys/interviews and decision aids, several were included more often in decision aids as opposed to surveys/interviews (e.g., STI prevention, noncontraceptive benefits, how the method is used, requirement of a healthcare provider), and vice versa (e.g., a woman's vicarious experience with contraceptive methods). Key attributes mentioned in both surveys/interviews and decision aids include efficacy (29 total mentioned) and side effects/health risks (28 total mentioned). While a limited number of decision support tools were formally evaluated, many were not rigorously studied.

CONCLUSIONS

Many attributes were identified as potentially important to women choosing a method of contraception, but these were inconsistently included in the reviewed resources. Formal evaluation of decision support tools for contraceptive choice and involvement of users in the development process may lead to more user-centered design and implementation.

Spermicide used alone for contraception

BACKGROUND

Spermicides have been used as contraceptives for thousands of years. Despite this long use, only recently have studies examined the comparative efficacy and acceptability of these vaginal medications. Spermicides contain an active ingredient (most commonly nonoxynol-9) and a formulation used to disperse the product, such as foam or vaginal suppository.

OBJECTIVES

This review examined all known randomized controlled trials of a spermicide used alone for contraception.

SEARCH METHODS

In August 2013, we searched the following computerized databases for randomized controlled trials of spermicides for contraception: CENTRAL, MEDLINE, POPLINE, LILACS, EMBASE, ClinicalTrials.gov, and ICTRP. For the initial review, we examined the reference lists of trials found as well as those of review articles and textbook chapters.

SELECTION CRITERIA

We included any trial of a commercial product used alone for contraception. Each included trial must have provided sufficient information to determine pregnancy rates.

DATA COLLECTION AND ANALYSIS

Two authors independently extracted information from the trials identified. We did not conduct a meta-analysis, since most trials had large losses to follow up. We entered the data into tables and presented the results descriptively.

MAIN RESULTS

We located reports from 14 trials for the initial review, but have not identified any new trials since then. In the largest trial to date, the gel (Advantage S) containing the lowest dose of nonoxynol-9 (52.5 mg) was significantly less effective in preventing pregnancy than were gels with higher doses of the same agent (100 mg and 150 mg). Probabilities of pregnancy by six months were 22% for the 52.5 mg gel, 16% for the 100 mg dose, and 14% for the 150 mg dose. In the same trial, the three different vehicles with 100 mg of nonoxynol-9 had similar efficacy. Interpretation of these figures is limited, since 39% of participants discontinued the method or were lost from the trial. Few important differences in efficacy emerged in other trials.

AUTHORS' CONCLUSIONS

The probability of pregnancy varied widely in reported trials. A gel containing nonoxynol-9 52.5 mg was inferior to two other products tested in the largest trial. Aside from this finding, personal characteristics and behavior of users may be more important than characteristics of the spermicide products in determining the probability of pregnancy. Gel was liked more than the film or vaginal suppository in the largest trial. Spermicide trials have the dual challenges of difficult recruitment and high discontinuation rates; the latter threatens trial validity.

Spermicide used alone for contraception

BACKGROUND

Spermicides have been used as contraceptives for thousands of years. Despite this long use, only recently have studies examined the comparative efficacy and acceptability of these vaginal medications. Spermicides contain an active ingredient (most commonly nonoxynol-9) and a formulation used to disperse the product, such as foam or vaginal suppository.

OBJECTIVES

This review examined all known randomized controlled trials of a spermicide used alone for contraception.

SEARCH METHODS

In August 2013, we searched the following computerized databases for randomized controlled trials of spermicides for contraception: CENTRAL, MEDLINE, POPLINE, LILACS, EMBASE, ClinicalTrials.gov, and ICTRP. For the initial review, we examined the reference lists of trials found as well as those of review articles and textbook chapters.

SELECTION CRITERIA

We included any trial of a commercial product used alone for contraception. Each included trial must have provided sufficient information to determine pregnancy rates.

DATA COLLECTION AND ANALYSIS

Two authors independently extracted information from the trials identified. We did not conduct a meta-analysis, since most trials had large losses to follow up. We entered the data into tables and presented the results descriptively.

MAIN RESULTS

We located reports from 14 trials for the initial review, but have not identified any new trials since then. In the largest trial to date, the gel (Advantage S) containing the lowest dose of nonoxynol-9 (52.5 mg) was significantly less effective in preventing pregnancy than were gels with higher doses of the same agent (100 mg and 150 mg). Probabilities of pregnancy by six months were 22% for the 52.5 mg gel, 16% for the 100 mg dose, and 14% for the 150 mg dose. In the same trial, the three different vehicles with 100 mg of nonoxynol-9 had similar efficacy. Interpretation of these figures is limited, since 39% of participants discontinued the method or were lost from the trial. Few important differences in efficacy emerged in other trials.

AUTHORS' CONCLUSIONS

The probability of pregnancy varied widely in reported trials. A gel containing nonoxynol-9 52.5 mg was inferior to two other products tested in the largest trial. Aside from this finding, personal characteristics and behavior of users may be more important than characteristics of the spermicide products in determining the probability of pregnancy. Gel was liked more than the film or vaginal suppository in the largest trial. Spermicide trials have the dual challenges of difficult recruitment and high discontinuation rates; the latter threatens trial validity.

Emergency contraception

This review will focus on the available methods for emergency contraception (EC), efficacy, side effects and mechanisms of action. Copper intrauterine device (IUD) has been shown to be the most effective method for EC which can be continually used for regular contraception. However, this possibility is seldom used and may be little known. Among the hormonal EC methods 1.5 mg levonorgestrel is the most widely used EC pill while the more recently developed Ulipristal acetate (UPA) has been shown to be the most effective option. This is probably due to a more pronounced prevention of follicular rupture compared with other hormonal EC methods. Knowledge is needed to better advise lactating women and obese women on optimal EC method. Furthermore a possible interaction of UPA with regular hormonal contraception and possibilities for "bridging" from EC to regular contraception needs to be explored. To increase efficacy future studies should focus on EC methods that target the endometrium.

A clinical guideline for intrauterine device use in adolescents

PURPOSE

To present an evidence-based review of the data for and against the use of the intrauterine device (IUD) in adolescent females and to provide guidelines for selection of appropriate candidates.

DATA SOURCES

Clinical research, expert opinions, and systematic reviews of IUD use in adolescents.

CONCLUSIONS

The use of the IUD in adolescents has been questioned in the past as a result of concerns surrounding increased risks for pelvic inflammatory disease and infertility in adolescents. Current research reveals no contraindications to IUD use based solely on age or parity and illuminates many benefits to use, including a decrease in menorrhagia and dysmenorrhea.

IMPLICATIONS FOR PRACTICE

The U.S. adolescent pregnancy rates rose from 2005 to 2007, reversing a decade-long downward trend. Adolescents need safe, effective, user-friendly contraceptive methods. IUDs are a safe and effective option for adolescents and provide an additional contraceptive option for nurse practitioners to offer their patients to prevent unintended pregnancy and enhance adolescent sexual health and well-being. Proper selection of candidates for IUD use can mitigate clinical and legal risks associated with IUD use.

Communicating contraceptive effectiveness: a randomized controlled trial

INTRODUCTION

Increasing the knowledge of women on effectiveness of contraceptive methods can lead to the use of more effective methods and reduce unwanted pregnancies and adverse outcomes. We aimed to compare three different approaches for increasing women's understanding of effectiveness of contraceptive methods.

METHODS

We ran-domly assigned 630 eligible women of reproductive age to one of the three groups. Each woman received one of three charts presenting pregnancy risk with each contraceptive method. Participants before and while reviewing the chart, answered to three key ques-tions about the effectiveness of the methods. The data were analyzed using chi-square, ANOVA and McNemar's tests in SPSS version 13.

RESULTS

The most important reasons for choosing contraceptive methods were their effectiveness (45%), ease of use (18%) and few side effects (14%). At baseline, the participants' knowledge about the effective-ness of the methods was poor. Correct answers were 44% about comparing the effec-tiveness of the combined pills vs. that of condoms, 50% about intrauterine devices vs. injectables, and 52% about condoms vs. withdrawal. While reviewing the charts, the percentages significantly (p < 0.001) increased to 80%, 84% and 85%, respectively. All the three charts almost equally increased the correct responds to the questions.

CONCLUSION

The three approaches had considerable and nearly identical effects on the promotion of women's knowledge about effectiveness of the contraceptive methods. Therefore, appropriate use of the charts is required during counseling sessions for contraceptive choice because it is impossible to have informed choice of the method without understanding their effectiveness.

Randomized controlled trial of a computer-based module to improve contraceptive method choice

BACKGROUND

Unintended pregnancy is common in the United States, and interventions are needed to improve contraceptive use among women at higher risk of unintended pregnancy, including Latinas and women with low educational attainment.

STUDY DESIGN

A three-arm randomized controlled trial was conducted at two family planning sites serving low-income, predominantly Latina populations. The trial tested the efficacy of a computer-based contraceptive assessment module in increasing the proportion of patients choosing an effective method of contraception (<10 pregnancies/100 women per year, typical use). Participants were randomized to complete the module and receive tailored health materials, to complete the module and receive generic health materials, or to a control condition.

RESULTS

In intent-to-treat analyses adjusted for recruitment site (n=2231), family planning patients who used the module were significantly more likely to choose an effective contraceptive method: 75% among those who received tailored materials [odds ratio (OR)=1.56; 95% confidence interval (CI): 1.23-1.98] and 78% among those who received generic materials (OR=1.74; 95% CI: 1.35-2.25), compared to 65% among control arm participants.

CONCLUSIONS

The findings support prior research suggesting that patient-centered interventions can positively influence contraceptive method choice.

Provision of contraceptive services to women with diabetes mellitus

BACKGROUND

Women with diabetes mellitus who delay pregnancy until glycemic control is achieved experience lower rates of adverse pregnancy outcomes.

OBJECTIVE

To compare rates of provision of contraceptive services among women with diabetes mellitus and women without chronic medical conditions.

DESIGN

A retrospective cohort study of 459,181 women aged 15-44 who had continuous membership and pharmacy benefits in a managed care organization in Northern California between January 2006 and June 2007. Rates of documented provision of contraceptive counseling, prescriptions, and services were compared between women with diabetes and women without chronic medical conditions.

RESULTS

Among 8,182 women with diabetes and 122,921 women without any chronic conditions, women with diabetes were less likely than women without a chronic condition to have documented receipt of any contraceptive counseling, prescriptions, or services (47.8% vs 62.0%, p < 0.001). After controlling for age and race, women with diabetes were more likely to have undergone tubal sterilization compared to women without a chronic condition (OR = 1.41, 95% CI 1.30-1.54), but less likely to have received highly effective, reversible methods of contraception such as intrauterine contraception (OR = 0.68, 95% CI 0.61-0.75). In addition, more women with diabetes had undergone hysterectomy, which is rarely performed solely for contraceptive purposes.

CONCLUSIONS

Women with diabetes were less likely to receive highly effective reversible contraception and more likely to undergo sterilization procedures. Increasing the use of highly effective reversible contraceptives may help diabetic women who want to retain their fertility to delay pregnancy until glycemic control is achieved.

Decision aids for people facing health treatment or screening decisions

BACKGROUND

Decision aids prepare people to participate in decisions that involve weighing benefits, harms, and scientific uncertainty.

OBJECTIVES

To evaluate the effectiveness of decision aids for people facing treatment or screening decisions.

SEARCH STRATEGY

For this update, we searched from January 2006 to December 2009 in MEDLINE (Ovid); Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library, issue 4 2009); CINAHL (Ovid) (to September 2008 only); EMBASE (Ovid); PsycINFO (Ovid); and grey literature. Cumulatively, we have searched each database since its start date.

SELECTION CRITERIA

We included published randomised controlled trials (RCTs) of decision aids, which are interventions designed to support patients' decision making by providing information about treatment or screening options and their associated outcomes, compared to usual care and/or alternative interventions. We excluded studies in which participants were not making an active treatment or screening decision.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened abstracts for inclusion, extracted data, and assessed potential risk of bias. The primary outcomes, based on the International Patient Decision Aid Standards, were:A) decision attributes;B) decision making process attributes.Secondary outcomes were behavioral, health, and health system effects. We pooled results of RCTs using mean differences (MD) and relative risks (RR), applying a random effects model.

MAIN RESULTS

Of 34,316 unique citations, 86 studies involving 20,209 participants met the eligibility criteria and were included. Thirty-one of these studies are new in this update. Twenty-nine trials are ongoing. There was variability in potential risk of bias across studies. The two criteria that were most problematic were lack of blinding and the potential for selective outcome reporting, given that most of the earlier trials were not registered.Of 86 included studies, 63 (73%) used at least one measure that mapped onto an IPDAS effectiveness criterion: A) criteria involving decision attributes: knowledge scores (51 studies); accurate risk perceptions (16 studies); and informed value-based choice (12 studies); and B) criteria involving decision process attributes: feeling informed (30 studies) and feeling clear about values (18 studies).A) Criteria involving decision attributes:Decision aids performed better than usual care interventions by increasing knowledge (MD 13.77 out of 100; 95% confidence interval (CI) 11.40 to 16.15; n = 26). When more detailed decision aids were compared to simpler decision aids, the relative improvement in knowledge was significant (MD 4.97 out of 100; 95% CI 3.22 to 6.72; n = 15). Exposure to a decision aid with expressed probabilities resulted in a higher proportion of people with accurate risk perceptions (RR 1.74; 95% CI 1.46 to 2.08; n = 14). The effect was stronger when probabilities were expressed in numbers (RR 1.93; 95% CI 1.58 to 2.37; n = 11) rather than words (RR 1.27; 95% CI 1.09 to 1.48; n = 3). Exposure to a decision aid with explicit values clarification compared to those without explicit values clarification resulted in a higher proportion of patients achieving decisions that were informed and consistent with their values (RR 1.25; 95% CI 1.03 to 1.52; n = 8).B) Criteria involving decision process attributes:Decision aids compared to usual care interventions resulted in: a) lower decisional conflict related to feeling uninformed (MD -6.43 of 100; 95% CI -9.16 to -3.70; n = 17); b) lower decisional conflict related to feeling unclear about personal values (MD -4.81; 95% CI -7.23 to -2.40; n = 14); c) reduced the proportions of people who were passive in decision making (RR 0.61; 95% CI 0.49 to 0.77; n = 11); and d) reduced proportions of people who remained undecided post-intervention (RR 0.57; 95% CI 0.44 to 0.74; n = 9). Decision aids appear to have a positive effect on patient-practitioner communication in the four studies that measured this outcome. For satisfaction with the decision (n = 12) and/or the decision making process (n = 12), those exposed to a decision aid were either more satisfied or there was no difference between the decision aid versus comparison interventions. There were no studies evaluating the decision process attributes relating to helping patients to recognize that a decision needs to be made or understand that values affect the choice.C) Secondary outcomesExposure to decision aids compared to usual care continued to demonstrate reduced choice of: major elective invasive surgery in favour of conservative options (RR 0.80; 95% CI 0.64 to 1.00; n = 11). Exposure to decision aids compared to usual care also resulted in reduced choice of PSA screening (RR 0.85; 95% CI 0.74 to 0.98; n = 7). When detailed compared to simple decision aids were used, there was reduced choice of menopausal hormones (RR 0.73; 95% CI 0.55 to 0.98; n = 3). For other decisions, the effect on choices was variable. The effect of decision aids on length of consultation varied from -8 minutes to +23 minutes (median 2.5 minutes). Decision aids do not appear to be different from comparisons in terms of anxiety (n = 20), and general health outcomes (n = 7), and condition specific health outcomes (n = 9). The effects of decision aids on other outcomes (adherence to the decision, costs/resource use) were inconclusive.

AUTHORS' CONCLUSIONS

New for this updated review is evidence that: decision aids with explicit values clarification exercises improve informed values-based choices; decision aids appear to have a positive effect on patient-practitioner communication; and decision aids have a variable effect on length of consultation.Consistent with findings from the previous review, which had included studies up to 2006: decision aids increase people's involvement, and improve knowledge and realistic perception of outcomes; however, the size of the effect varies across studies. Decision aids have a variable effect on choices. They reduce the choice of discretionary surgery and have no apparent adverse effects on health outcomes or satisfaction. The effects on adherence with the chosen option, patient-practitioner communication, cost-effectiveness, and use with developing and/or lower literacy populations need further evaluation. Little is known about the degree of detail that decision aids need in order to have positive effects on attributes of the decision or decision-making process.

Reproductive health characteristics of marijuana and cocaine users: results from the 2002 National Survey of Family Growth

CONTEXT

Illicit drug use is associated with risky sexual behaviors in adolescents and young adults. However, few studies have examined these associations among drug users of all reproductive ages, using a control group of nonusers.

METHODS

Associations between marijuana and cocaine use, and outcomes related to sexual behaviors and reproductive health, were assessed using data from the 2002 National Survey of Family Growth. Overall, 4,928 men and 7,643 women aged 15-44 were interviewed. Chi-square tests, t tests and multivariable logistic regression analyses were used; in supplementary analyses, men and women were stratified by age-group (25 or younger, and older than 25), to capture the understudied older adults who use drugs.

RESULTS

Twenty-seven percent of men and 16% of women reported use of marijuana or cocaine in the last year. Drug users were younger than nonusers at first vaginal sex (mean, 15.2-16.1 vs. 17.3-17.5 years) and were more likely to have engaged in risky sexual behaviors in the last year, including having had sex with a nonmonogamous partner (odds ratios, 3.3-5.2 for men and 2.9-6.5 for women), while high on alcohol or drugs (10.1-18.0 and 8.1-24.2), or in exchange for money or drugs (2.7-2.8 and 2.3-9.2). They also were more likely to have undergone STD testing or treatment. Drug use was associated with risky sexual behaviors in both age-groups.

CONCLUSION

Programs aimed at reducing sexual risks among drug users should address the behaviors of men and women of all reproductive ages.

Decision aids for people facing health treatment or screening decisions

BACKGROUND

Decision aids prepare people to participate in 'close call' decisions that involve weighing benefits, harms, and scientific uncertainty.

OBJECTIVES

To conduct a systematic review of randomised controlled trials (RCTs) evaluating the efficacy of decision aids for people facing difficult treatment or screening decisions.

SEARCH STRATEGY

We searched MEDLINE (Ovid) (1966 to July 2006); Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library; 2006, Issue 2); CINAHL (Ovid) (1982 to July 2006); EMBASE (Ovid) (1980 to July 2006); and PsycINFO (Ovid) (1806 to July 2006). We contacted researchers active in the field up to December 2006. There were no language restrictions.

SELECTION CRITERIA

We included published RCTs of interventions designed to aid patients' decision making by providing information about treatment or screening options and their associated outcomes, compared to no intervention, usual care, and alternate interventions. We excluded studies in which participants were not making an active treatment or screening decision, or if the study's intervention was not available to determine that it met the minimum criteria to qualify as a patient decision aid.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened abstracts for inclusion, and extracted data from included studies using standardized forms. The primary outcomes focused on the effectiveness criteria of the International Patient Decision Aid Standards (IPDAS) Collaboration: attributes of the decision and attributes of the decision process. We considered other behavioural, health, and health system effects as secondary outcomes. We pooled results of RCTs using mean differences (MD) and relative risks (RR) using a random effects model.

MAIN RESULTS

This update added 25 new RCTs, bringing the total to 55. Thirty-eight (69%) used at least one measure that mapped onto an IPDAS effectiveness criterion: decision attributes: knowledge scores (27 trials); accurate risk perceptions (11 trials); and value congruence with chosen option (4 trials); and decision process attributes: feeling informed (15 trials) and feeling clear about values (13 trials).This review confirmed the following findings from the previous (2003) review. Decision aids performed better than usual care interventions in terms of: a) greater knowledge (MD 15.2 out of 100; 95% CI 11.7 to 18.7); b) lower decisional conflict related to feeling uninformed (MD -8.3 of 100; 95% CI -11.9 to -4.8); c) lower decisional conflict related to feeling unclear about personal values (MD -6.4; 95% CI -10.0 to -2.7); d) reduced the proportion of people who were passive in decision making (RR 0.6; 95% CI 0.5 to 0.8); and e) reduced proportion of people who remained undecided post-intervention (RR 0.5; 95% CI 0.3 to 0.8). When simpler decision aids were compared to more detailed decision aids, the relative improvement was significant in knowledge (MD 4.6 out of 100; 95% CI 3.0 to 6.2) and there was some evidence of greater agreement between values and choice.In this review, we were able to explore the use of probabilities in decision aids. Exposure to a decision aid with probabilities resulted in a higher proportion of people with accurate risk perceptions (RR 1.6; 95% CI 1.4 to 1.9). The effect was stronger when probabilities were measured quantitatively (RR 1.8; 95% CI 1.4 to 2.3) versus qualitatively (RR 1.3; 95% CI 1.1 to 1.5).As in the previous review, exposure to decision aids continued to demonstrate reduced rates of: elective invasive surgery in favour of conservative options, decision aid versus usual care (RR 0.8; 95% CI 0.6 to 0.9); and use of menopausal hormones, detailed versus simple aid (RR 0.7; 95% CI 0.6 to 1.0). There is now evidence that exposure to decision aids results in reduced PSA screening, decision aid versus usual care (RR 0.8; 95% CI 0.7 to 1.0) . For other decisions, the effect on decisions remains variable.As in the previous review, decision aids are no better than comparisons in affecting satisfaction with decision making, anxiety, and health outcomes. The effects of decision aids on other outcomes (patient-practitioner communication, consultation length, continuance, resource use) were inconclusive.There were no trials evaluating the IPDAS decision process criteria relating to helping patients to recognize a decision needs to be made, understand that values affect the decision, or discuss values with the practitioner.

AUTHORS' CONCLUSIONS

Patient decision aids increase people's involvement and are more likely to lead to informed values-based decisions; however, the size of the effect varies across studies. Decision aids have a variable effect on decisions. They reduce the use of discretionary surgery without apparent adverse effects on health outcomes or satisfaction. The degree of detail patient decision aids require for positive effects on decision quality should be explored. The effects on continuance with chosen option, patient-practitioner communication, consultation length, and cost-effectiveness need further evaluation.

Do instructions for over-the-counter pre-coital female contraceptives promote "perfect use"?

BACKGROUND

This study was conducted to estimate the readability and related features of English-language over-the-counter (OTC) pre-coital female contraceptive (PFC) instructions.

STUDY DESIGN

We identified and purchased all currently available OTC PFCs (n=8), including Encare (Contraceptive Gel and Insert), F.C. Female Condom, Ortho Options (Conceptrol, Delfen and Gyncol II Jelly), Today Sponge and VCF Vaginal Film. Reading grade level was calculated using the Simple Measure of Gobbledygook. Text point size was measured and total number of graphics was tallied. Graphic dimensions were also measured. We also assessed OTC PFC instructions on four main criteria--derived from the "User-Friendliness Tool (UFT)"--including layout features, graphic characteristics, presence of a clear message and presentation of manageable information.

RESULTS

Reading level ranged from 8th to 12th grade (mean+/-SD=10.0+/-1.2). Mean page length was 24.4+/-7.0 cm (9.6+/-2.76 in.), while average page width was 20.3+/-13.8 cm (7.99+/-5.43 in.). Average text point size was 7.9+/-2.3 (range=6-12). Illustrations, predominantly line drawings, were used throughout (range=3-11), and most were similar in size to a matchbox. None of the "How to Use" sections scored high in all criteria on the UFT.

CONCLUSIONS

"How to Use" sections of OTC PFC instructions should be revised to be easier to read and more user friendly. Ideally, the gap between "typical" and "perfect" contraceptive efficacy could potentially be narrowed if instructions were developed that the large majority of women could easily understand.

Strategies for communicating contraceptive effectiveness

BACKGROUND

Knowledge of contraceptive effectiveness is crucial to making an informed choice. The consumer has to comprehend the pros and cons of the contraceptive methods being considered. Choice may be influenced by understanding the likelihood of pregnancy with each method and factors that influence effectiveness.

OBJECTIVES

To review all randomized controlled trials comparing strategies for communicating to consumers the effectiveness of contraceptives in preventing pregnancy.

SEARCH STRATEGY

We searched the computerized databases MEDLINE, POPLINE, CENTRAL, PsycINFO, and EMBASE for studies of communicating contraceptive effectiveness. We also examined references lists of relevant articles, and wrote to known investigators for information about other published or unpublished trials.

SELECTION CRITERIA

We included randomized controlled trials that compared methods for communicating contraceptive effectiveness to consumers. The comparison could be usual practice or an alternative to the experimental intervention.

DATA COLLECTION AND ANALYSIS

Data were abstracted by two authors and entered into RevMan. For dichotomous variables, the Peto odds ratio (OR) with 95% confidence intervals (CI) was calculated. For continuous variables, the weighted mean difference (WMD) was computed.

MAIN RESULTS

Five trials met the inclusion criteria. In one study, knowledge gain favored a slide-and-sound presentation versus a physician's oral presentation (WMD -19.00; 95% CI -27.52 to -10.48). Another trial showed a table with effectiveness categories led to more correct answers than one based on numbers [ORs were 2.42 (95% CI 1.43 to 4.12) and 2.19 (95% CI 1.21 to 3.97)] or a table with categories and numbers [ORs were 2.58 (95% CI 1.5 to 4.42) and 2.03 (95% CI 1.13 to 3.64)]. One trial examined contraceptive choice: women in the expanded program were more likely to choose sterilization (OR 4.26; 95% CI 2.46 to 7.37) or use a modern contraceptive method (OR 2.35; 95% CI 1.82 to 3.03). No trial had an explicit theoretical base, but each used concepts from common theories or models.

AUTHORS' CONCLUSIONS

We have limited evidence about what works to help consumers choose an appropriate contraceptive method. For presenting pregnancy risk data, one trial showed that categories were better than numbers. In another trial, audiovisual aids worked better than the usual oral presentation. Strategies for communicating information should be examined in clinical settings and assessed for effect on contraceptive choice and retention of knowledge. To expand the knowledge base of what works in contraceptive counseling, randomized trials could intentionally use and test theories or models.

The relationship between body mass index and unintended pregnancy: results from the 2002 National Survey of Family Growth

BACKGROUND

The study was conducted to characterize the relationship between body mass index (BMI) and unintended pregnancy, contraceptive use patterns, and perceived fertility.

METHODS

This study employed a cross-sectional, nationally representative database (2002 National Survey of Family Growth). Unintended pregnancy was compared among BMI groups [normal (<25 m/kg(2)), overweight (25-30 m/kg(2)) and obese (>30 m/kg(2))]. Analyses also evaluated the association between demographic, socioeconomic, behavioral and health-related variables and BMI. Multiple logistic regression with adjustment for sampling design was used to measure associations of interest.

RESULTS

BMI data were available from 6690 nonpregnant women. Of these, 3600 (53.6%) were normal weight, 1643 (25%) were overweight and 1447 (21.4%) were obese. Compared to women with normal BMIs, the risk of unintended pregnancy in the last 5 years did not differ among overweight [adjusted OR 0.95 (95% CI 0.77-1.17)] or obese [adjusted OR 0.87 (95% CI 0.70-1.09)] women. There were no differences in contraceptive use patterns or perceived fertility among BMI groups.

CONCLUSION

Data from the 2002 NSFG do not support an association between obesity and unintended pregnancy.

Women's attitudes towards mechanisms of action of family planning methods: survey in primary health centres in Pamplona, Spain

Background

Informed consent in family planning includes knowledge of mechanism of action. Some methods of family planning occasionally work after fertilization. Knowing about postfertilization effects may be important to some women before choosing a certain family planning method. The objective of this survey is to explore women's attitudes towards postfertilization effects of family planning methods, and beliefs and characteristics possibly associated with those attitudes.

Methods

Cross-sectional survey in a sample of 755 potentially fertile women, aged 18–49, from Primary Care Health Centres in Pamplona, Spain. Participants were given a 30-item, self-administered, anonymous questionnaire about family planning methods and medical and surgical abortion. Logistic regression was used to identify variables associated with women's attitudes towards postfertilization effects.

Results

The response rate was 80%. The majority of women were married, held an academic degree and had no children. Forty percent of women would not consider using a method that may work after fertilization but before implantation and 57% would not consider using one that may work after implantation. While 35.3% of the sample would stop using a method if they learned that it sometimes works after fertilization, this percentage increased to 56.3% when referring to a method that sometimes works after implantation. Women who believe that human life begins at fertilization and those who consider it is important to distinguish between natural and induced embryo loss were less likely to consider the use of a method with postfertilization effects.

Conclusion

Information about potential postfertilization effects of family planning methods may influence women's acceptance and choice of a particular family planning method. Additional studies in other populations are necessary to evaluate whether these beliefs are important to those populations.

Family planning: the unfinished agenda

Promotion of family planning in countries with high birth rates has the potential to reduce poverty and hunger and avert 32% of all maternal deaths and nearly 10% of childhood deaths. It would also contribute substantially to women's empowerment, achievement of universal primary schooling, and long-term environmental sustainability. In the past 40 years, family-planning programmes have played a major part in raising the prevalence of contraceptive practice from less than 10% to 60% and reducing fertility in developing countries from six to about three births per woman. However, in half the 75 larger low-income and lower-middle income countries (mainly in Africa), contraceptive practice remains low and fertility, population growth, and unmet need for family planning are high. The cross-cutting contribution to the achievement of the Millennium Development Goals makes greater investment in family planning in these countries compelling. Despite the size of this unfinished agenda, international funding and promotion of family planning has waned in the past decade. A revitalisation of the agenda is urgently needed. Historically, the USA has taken the lead but other governments or agencies are now needed as champions. Based on the sizeable experience of past decades, the key features of effective programmes are clearly established. Most governments of poor countries already have appropriate population and family-planning policies but are receiving too little international encouragement and funding to implement them with vigour. What is currently missing is political willingness to incorporate family planning into the development arena.

Communicating contraceptive effectiveness: A randomized controlled trial to inform a World Health Organization family planning handbook

OBJECTIVE

The objective of the study was to compare 3 different approaches for increasing clients' understanding of contraceptive effectiveness.

STUDY DESIGN

We randomized 900 reproductive-age women in India and Jamaica to 1 of 3 charts presenting pregnancy risk.

RESULTS

The most important reason for choosing a contraceptive was how well it prevents pregnancy (54%) followed by few side effects (17%). At baseline, knowledge about contraceptive effectiveness was poor. About half knew oral contraceptive pills are more effective than condoms (46%) and intrauterine devices are more effective than injectables (50%). All 3 charts improved knowledge significantly (P < .01) for these 2 questions. No chart improved knowledge better than any other (P > .05). The chart ranking contraceptive methods on a continuum was judged slightly easier to understand than the other 2 charts.

CONCLUSION

Only with accurate understanding of pregnancy risk can clients make informed choices. Our results have already informed a global handbook for family planning providers to use the chart ranking contraceptive methods on a continuum.

Barriers to contraceptive use in product labeling and practice guidelines

Many contraceptives are encumbered with potentially unnecessary restrictions on their use. Indeed, fear of side effects, fostered by alarmist labeling, is a leading reason that women do not use contraceptives. In the United States, hormonal methods currently require a prescription, although research suggests that women can adequately screen themselves for contraindications, manage side effects, and determine an appropriate initiation date, leaving little need for routine direct physician involvement. Sizing, spermicidal use, and length-of-wear limits burden users of cervical barriers and may be unnecessary. Despite recent changes in the labeling of intrauterine devices, clinicians commonly restrict use of this method and in some countries may limit the types of providers authorized to insert them. Although in some cases additional research is necessary, existing data indicate that evidence-based demedicalization of contraceptive provision could reduce costs and improve access.

Consistency between most important reasons for using contraception and current method used: the influence of health care providers

OBJECTIVE

To identify factors related to consistency between women's "most important" reason for using contraception and their current contraceptive method.

METHODS

A sample of 433 women completed a written questionnaire on demographics, contraceptive use history and the "most important" reason for using contraception. Women were grouped by whether their current contraceptive method "agreed" or "disagreed" with their "most important" reason for contracepting. Multivariable regression was used to identify factors associated with consistency between stated "most important" reason and current method used ("agreed").

RESULTS

Current contraceptive method was inconsistent with the "most important" reason for using a method in 25% of women. Demographic characteristics and knowledge of contraceptive effectiveness did not differ between the "agreed" and "disagreed" groups. Women using a method consistent with their reason were more likely to have discussed contraception with a health care provider (RR=1.59, 95% CI 1.13-2.25) even after adjusting for source of contraceptive method or source of contraceptive information (RR=1.57, 95% CI 1.10-2.23).

CONCLUSION

Contact with a health care provider was the only factor associated with consistency between birth control method and reasons for initiating contraception. This association appears to be independent of knowledge about contraceptive effectiveness.

Spermicide used alone for contraception

BACKGROUND

Spermicides have been used as contraceptives for thousands of years. Despite this long use, only recently have studies examined the comparative efficacy and acceptability of these vaginal medications. Spermicides contain an active ingredient (most commonly nonoxynol-9) and a formulation used to disperse the product, such as foam or vaginal suppository.

OBJECTIVES

This review examined all known randomized controlled trials of a spermicide used alone for contraception.

SEARCH STRATEGY

We searched the following computerized databases from inception to July 2004 for randomized controlled trials of spermicides for contraception: Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, POPLINE, LILACS, and EMBASE. We examined the reference list of each trial found as well as that of review articles and textbook chapters.

SELECTION CRITERIA

We included any trial of a commercial product used alone for contraception. Each included trial must have provided sufficient information to determine pregnancy rates. We located reports from 14 trials.

DATA COLLECTION AND ANALYSIS

Two reviewers independently extracted information from the trials identified. We did not conduct a meta-analysis, since most trials had large losses to follow-up. We entered the data into tables and presented the results descriptively.

MAIN RESULTS

In the largest trial to date, the gel (Advantage S) containing the lowest dose of nonoxynol-9 (52.5 mg) was significantly less effective in preventing pregnancy than were gels with higher doses of the same agent (100 mg and 150 mg). Probabilities of pregnancy by six months were 22% for the 52.5 mg gel, 16% for the 100 mg dose, and 14% for the 150 mg dose. In the same trial, the three different vehicles with 100 mg of nonoxynol-9 had similar efficacy. Interpretation of these figures is limited, since 39% of participants discontinued the method or were lost from the trial. Few important differences in efficacy emerged in other trials.

AUTHORS' CONCLUSIONS

The probability of pregnancy varied widely in reported trials. A gel containing nonoxynol-9 52.5 mg was inferior to two other products tested in the largest trial. Aside from this finding, personal characteristics and behavior of users may be more important than characteristics of the spermicide products in determining the probability of pregnancy. Gel was liked more than the film or vaginal suppository in the largest trial. Spermicide trials have the dual challenges of difficult recruitment and high discontinuation rates; the latter threatens trial validity.