Randomized trials versus observational studies in adolescent pregnancy prevention

Healthcare outcomes assessed with observational study designs compared with those assessed in randomized trials: a meta-epidemiological study

BACKGROUND

Researchers and decision-makers often use evidence from randomised controlled trials (RCTs) to determine the efficacy or effectiveness of a treatment or intervention. Studies with observational designs are often used to measure the effectiveness of an intervention in 'real world' scenarios. Numerous study designs and their modifications (including both randomised and observational designs) are used for comparative effectiveness research in an attempt to give an unbiased estimate of whether one treatment is more effective or safer than another for a particular population. An up-to-date systematic analysis is needed to identify differences in effect estimates from RCTs and observational studies. This updated review summarises the results of methodological reviews that compared the effect estimates of observational studies with RCTs from evidence syntheses that addressed the same health research question.

OBJECTIVES

To assess and compare synthesised effect estimates by study type, contrasting RCTs with observational studies. To explore factors that might explain differences in synthesised effect estimates from RCTs versus observational studies (e.g. heterogeneity, type of observational study design, type of intervention, and use of propensity score adjustment). To identify gaps in the existing research comparing effect estimates across different study types.

SEARCH METHODS

We searched MEDLINE, the Cochrane Database of Systematic Reviews, Web of Science databases, and Epistemonikos to May 2022. We checked references, conducted citation searches, and contacted review authors to identify additional reviews.

SELECTION CRITERIA

We included systematic methodological reviews that compared quantitative effect estimates measuring the efficacy or effectiveness of interventions tested in RCTs versus in observational studies. The included reviews compared RCTs to observational studies (including retrospective and prospective cohort, case-control and cross-sectional designs). Reviews were not eligible if they compared RCTs with studies that had used some form of concurrent allocation.

DATA COLLECTION AND ANALYSIS

Using results from observational studies as the reference group, we examined the relative summary effect estimates (risk ratios (RRs), odds ratios (ORs), hazard ratios (HRs), mean differences (MDs), and standardised mean differences (SMDs)) to evaluate whether there was a relatively larger or smaller effect in the ratio of odds ratios (ROR) or ratio of risk ratios (RRR), ratio of hazard ratios (RHR), and difference in (standardised) mean differences (D(S)MD). If an included review did not provide an estimate comparing results from RCTs with observational studies, we generated one by pooling the estimates for observational studies and RCTs, respectively. Across all reviews, we synthesised these ratios to produce a pooled ratio of ratios comparing effect estimates from RCTs with those from observational studies. In overviews of reviews, we estimated the ROR or RRR for each overview using observational studies as the reference category. We appraised the risk of bias in the included reviews (using nine criteria in total). To receive an overall low risk of bias rating, an included review needed: explicit criteria for study selection, a complete sample of studies, and to have controlled for study methodological differences and study heterogeneity. We assessed reviews/overviews not meeting these four criteria as having an overall high risk of bias. We assessed the certainty of the evidence, consisting of multiple evidence syntheses, with the GRADE approach.

MAIN RESULTS

We included 39 systematic reviews and eight overviews of reviews, for a total of 47. Thirty-four of these contributed data to our primary analysis. Based on the available data, we found that the reviews/overviews included 2869 RCTs involving 3,882,115 participants, and 3924 observational studies with 19,499,970 participants. We rated 11 reviews/overviews as having an overall low risk of bias, and 36 as having an unclear or high risk of bias. Our main concerns with the included reviews/overviews were that some did not assess the quality of their included studies, and some failed to account appropriately for differences between study designs - for example, they conducted aggregate analyses of all observational studies rather than separate analyses of cohort and case-control studies. When pooling RORs and RRRs, the ratio of ratios indicated no difference or a very small difference between the effect estimates from RCTs versus from observational studies (ratio of ratios 1.08, 95% confidence interval (CI) 1.01 to 1.15). We rated the certainty of the evidence as low. Twenty-three of 34 reviews reported effect estimates of RCTs and observational studies that were on average in agreement. In a number of subgroup analyses, small differences in the effect estimates were detected: - pharmaceutical interventions only (ratio of ratios 1.12, 95% CI 1.04 to 1.21); - RCTs and observational studies with substantial or high heterogeneity; that is, I2 ≥ 50% (ratio of ratios 1.11, 95% CI 1.04 to 1.18); - no use (ratio of ratios 1.07, 95% CI 1.03 to 1.11) or unclear use (ratio of ratios 1.13, 95% CI 1.03 to 1.25) of propensity score adjustment in observational studies; and - observational studies without further specification of the study design (ratio of ratios 1.06, 95% CI 0.96 to 1.18). We detected no clear difference in other subgroup analyses.

AUTHORS' CONCLUSIONS

We found no difference or a very small difference between effect estimates from RCTs and observational studies. These findings are largely consistent with findings from recently published research. Factors other than study design need to be considered when exploring reasons for a lack of agreement between results of RCTs and observational studies, such as differences in the population, intervention, comparator, and outcomes investigated in the respective studies. Our results underscore that it is important for review authors to consider not only study design, but the level of heterogeneity in meta-analyses of RCTs or observational studies. A better understanding is needed of how these factors might yield estimates reflective of true effectiveness.

The role of randomized controlled trials, registries, observational databases in evaluating new interventions

Approaches to comparing safety and efficacy of interventions include analyzing data from randomized controlled trials (RCTs), registries and observational databases (ODBs). RCTs are regarded as the gold standard but data from such trials are sometimes unavailable because a disease is uncommon, because the intervention is uncommon, because of structural limitations or because randomization cannot be done for practical or (seemingly) ethical reasons. There are many examples of an unproved intervention being so widely-believed to be effective that clinical trialists and potential subjects decline randomization. Often, when a RCT is finally done the intervention is proved ineffective or even harmful. These situations are termed medical reversals and are not uncommon [1,2]. There is also the dilemma of when seemingly similar RCTs report discordant conclisions Data from high-quality registries, especially ODBs can be used when data from RCTs are unavailable but also have limitations. Biases and confounding co-variates may be unknown, difficult or impossible to identify and/or difficult to adjust for adequately. However, ODBs sometimes have large numbers of diverse subjects and often give answers more useful to clinicians than RCTs. Side-by-side comparisons suggest analyses from high-quality ODBs often give similar conclusions from high quality RCTs. Meta-analyses combining data from RCTs, registries and ODBs are sometimes appropriate. We suggest increased use of registries and ODBs to compare efficacy of interventions.

Comparative analysis of sexual behavior and assessment of awareness of STIs and HIV infection among young people of two generations

Background: A comparative analysis of the results of a survey of young people (belonging to two different generations: millennials and zoomers) on sexual behavior and awareness of STIs and HIV infection allows us to assess the existing characteristics of the sexual behavior of young people and contribute to the further improvement of preventive measures among young people regarding STI/HIV infection. Aims: Comparative analysis of sexual behavior and assessment of the level of knowledge about STIs and HIV infection among young people (generations Y and Z). Materials and methods: For a comparative assessment of the level of awareness on the issues of prevention and risky sexual behavior in relation to STIs and HIV infection, data from earlier sociological surveys of young people in 20012002 and in 20172020 in the city of Novosibirsk were used. Among the respondents, a questionnaire was used, consisting of 23 questions, developed by the staff of the Department of Dermatovenereology of the St. acad. I.P. Pavlov and the Center for the Sociology of Deviance and Social Control of the Institute of Sociology of the Russian Academy of Sciences, adapted by the authors. Statistical analysis was carried out using Microsoft Excel and SPSS programs. The 2 test and the independent Student's t-test were evaluated. Statistical significance was set as p0.05 Results: A total of 772 young men took part in the study, of which 321 students were interviewed in 2001-2002. (Generation Y), and 451 students in 2017-2020. (Generation Z). The results show that generations of young people (millineals and zoomers) differ from each other in terms of the source of information about STIs, sexual intercourse with strangers, condom use, and the frequency of same-sex sexual intercourse. Conclusions: There is a positive trend in the sexual behavior of the younger generation. But a more structured promotion of STI/HIV prevention is needed, which will take into account current trends and features of obtaining information from young people.

The relationship between consumption of pornography and consensual sexual practice: Results of a mixed method systematic review

This article reports on the findings of a systematic review of literature on pornography use and sexual consent published between January 2000 and December 2017. The review found that there exists little research explicitly addressing consent. There exists an extensive literature on the relationship between the consumption of pornography and sexual aggression/violence; however, this work fails to distinguish between consensual (kink, spanking, BDSM) and nonconsensual acts (sexual harassment and rape). Our thematic analysis found that there is no agreement in the literature reviewed as to whether consumption of pornography is correlated with better or worse understandings or practices of sexual consent. The majority of articles that identified correlations between aspects of sexual health and pornography consumption incorrectly assigned causality to pornography consumption.

A comprehensive review of reviews of school-based interventions to improve sexual-health

OBJECTIVE

To systematically review systematic reviews of school-based sexual-health and relationship Education (SHRE) programmes and, thereby, identify interventions and intervention components that promote reductions in risky sexual behaviour among young people.

METHODS

Electronic bibliographies were searched systematically to identify systematic reviews of school-based interventions targeting sexual-health. Results were summarised using a narrative synthesis.

RESULTS

Thirty-seven systematic reviews (summarising 224 primary randomised controlled trials) met our inclusion and quality assessment criteria. In general, these reviews analysed distinct sets of primary studies, and no comprehensive review of available primary studies was identified. Interventions were categorised into five types that segment this review literature. Unfortunately, many reviews reported weak and inconsistent evidence of behaviour change. Nonetheless, integration of review findings generated a list of 32 design, content and implementation characteristics that may enhance effectiveness of school-based, sexual-health interventions. Abstinence-only interventions were found to be ineffective in promoting positive changes in sexual behaviour. By contrast, comprehensive interventions, those specifically targeting HIV prevention, and school-based clinics were found to be effective in improving knowledge and changing attitudes, behaviours and health-relevant outcomes.

CONCLUSIONS

School-based interventions targeting risky sexual behaviour can be effective. Particular design, content and implementation characteristics appear to be associated with greater effectiveness. We recommend consideration of these characteristics by designers of school-based sexual-health interventions.

Diverse criteria and methods are used to compare treatment effect estimates: a scoping review

OBJECTIVES

To determine what criteria researchers use to assess whether the estimates of effect of an intervention on a dichotomous outcome are different when obtained using different study designs.

STUDY DESIGN AND SETTING

Scoping review of the literature. We included studies of dichotomous outcomes in which authors compared the estimates of effects from different study designs. We performed searches in electronic databases and in the list of references of relevant studies. Two reviewers independently selected studies and abstracted data. We created a list of the criteria used to compare estimates of effects between study designs, described their main features, and classified them using a clinical perspective.

RESULTS

We included 26 studies, from which we identified 24 criteria. Most of the studies focused on comparing estimates from observational studies and randomized controlled trials (n = 19). The most common criteria aimed to determine whether there was a difference or not (n = 18), provided guidance for such a judgment (n = 16), and were based on the point estimates (n = 11). We judged 14 criteria to be appropriate and classified them as either statistically related or clinically related.

CONCLUSION

We found that diverse criteria are used to compare effect estimates between study designs. Familiarity with these would aid in the interpretation of results from different studies regarding the same question.

Effectiveness of complex interventions focused on quality-of-life assessment to improve palliative care patients' outcomes: a systematic review

BACKGROUND

One of the most crucial palliative care challenges is in determining how patient' needs are defined and assessed. Assessing quality of life has been defined as a priority in palliative care, and it has become a central concept in palliative care practice.

AIM

To determine to what extent interventions focused on measuring quality of life in palliative care practice are effective in improving outcomes in palliative care patients.

DESIGN

Systematic review according to the recommendations of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement and hand searches.

DATA SOURCES

MEDLINE, CINAHL, EMBASE, PsycINFO, and the Cochrane Library were searched for articles published until June 2012, and through hand searching from references lists of included articles. Only studies that included adult palliative care patients, in any palliative care clinical practice setting of care, and with an experimental, quasi-experimental, or observational analytical study design were eligible for inclusion. All studies were independently reviewed by two investigators who scored them for methodological quality by using the Edwards Method Score.

RESULTS

In total, 11 articles (of 8579) incorporating information from 10 studies were included. Only three were randomized controlled trials. The quality of the evidence was found from moderate to low. Given a wide variability among patients' outcomes, individual effect size (ES) was possible for 6 out of 10 studies, 3 of which found a moderate ES on symptoms (ES = 0.68) and psychological (ES = 0.60) and social (ES = 0.55) dimensions.

CONCLUSION

Effectiveness of interventions focused on quality-of-life assessment is moderate. Additional studies should explore the complexity of the real palliative care world more accurately and understand the effects of independent variables included in complex palliative care interventions.

Using multiple types of studies in systematic reviews of health care interventions--a systematic review

BACKGROUND

A systematic review may evaluate different aspects of a health care intervention. To accommodate the evaluation of various research questions, the inclusion of more than one study design may be necessary. One aim of this study is to find and describe articles on methodological issues concerning the incorporation of multiple types of study designs in systematic reviews on health care interventions. Another aim is to evaluate methods studies that have assessed whether reported effects differ by study types.

METHODS AND FINDINGS

We searched PubMed, the Cochrane Database of Systematic Reviews, and the Cochrane Methodology Register on 31 March 2012 and identified 42 articles that reported on the integration of single or multiple study designs in systematic reviews. We summarized the contents of the articles qualitatively and assessed theoretical and empirical evidence. We found that many examples of reviews incorporating multiple types of studies exist and that every study design can serve a specific purpose. The clinical questions of a systematic review determine the types of design that are necessary or sufficient to provide the best possible answers. In a second independent search, we identified 49 studies, 31 systematic reviews and 18 trials that compared the effect sizes between randomized and nonrandomized controlled trials, which were statistically different in 35%, and not different in 53%. Twelve percent of studies reported both, different and non-different effect sizes.

CONCLUSIONS

Different study designs addressing the same question yielded varying results, with differences in about half of all examples. The risk of presenting uncertain results without knowing for sure the direction and magnitude of the effect holds true for both nonrandomized and randomized controlled trials. The integration of multiple study designs in systematic reviews is required if patients should be informed on the many facets of patient relevant issues of health care interventions.

A review of interventions with parents to promote the sexual health of their children

PURPOSE

To assess the effectiveness of interventions involving parents or carers intended to improve the sexual health of their children.

METHODS

Eleven databases were searched for evaluations of interventions with some parental involvement and with outcomes related to the sexual health of the parents' children. Studies had to be experimental, quasi-experimental, or of the before-and-after type. Results were analyzed in a narrative systematic review, taking account of methodological quality.

RESULTS

We identified adequately robust evaluations of 44 programs, delivered in diverse settings. In nearly all cases, the parenting component focused on improving parent-child communication about sex. In general, where measured, parent-child interaction and adolescents' knowledge and attitudes improved, but sexual behavior outcomes only improved in approximately half the studies. Three programs in which the parenting component made up at least one-fourth of the overall program were found, through randomized controlled trials, to modify some aspect of adolescents' sexual behavior. All programs involved parents for at least 14 hours, were community-based, and encouraged delayed sex.

CONCLUSIONS

Targeted programs with intensive parental involvement can modify adolescents' sexual behavior, although the review was limited by the lack of rigorous evaluations. Few programs addressed behavioral control, parent-child connectedness, or parental modeling, all suggested by observational research.

Randomisation to protect against selection bias in healthcare trials

BACKGROUND

Randomised trials use the play of chance to assign participants to comparison groups. The unpredictability of the process, if not subverted, should prevent systematic differences between comparison groups (selection bias). Differences due to chance will still occur and these are minimised by randomising a sufficiently large number of people.

OBJECTIVES

To assess the effects of randomisation and concealment of allocation on the results of healthcare studies.

SEARCH STRATEGY

We searched the Cochrane Methodology Register, MEDLINE, SciSearch and reference lists up to September 2009. In addition, we screened articles citing included studies (ISI Science Citation Index) and papers related to included studies (PubMed).

SELECTION CRITERIA

Eligible study designs were cohorts of studies, systematic reviews or meta-analyses of healthcare interventions that compared random allocation versus non-random allocation or adequate versus inadequate/unclear concealment of allocation in randomised trials. Outcomes of interest were the magnitude and direction of estimates of effect and imbalances in prognostic factors.

DATA COLLECTION AND ANALYSIS

We retrieved and assessed studies that appeared to meet the inclusion criteria independently. At least two review authors independently appraised methodological quality and extracted information. We prepared tabular summaries of the results for each comparison and assessed the results across studies qualitatively to identify common trends or discrepancies.

MAIN RESULTS

A total of 18 studies (systematic reviews or meta-analyses) met our inclusion criteria. Ten compared random allocation versus non-random allocation and nine compared adequate versus inadequate or unclear concealment of allocation within controlled trials. All studies were at high risk of bias.For the comparison of randomised versus non-randomised studies, four comparisons yielded inconclusive results (differed between outcomes or different modes of analysis); three comparisons showed similar results for random and non-random allocation; two comparisons had larger estimates of effect in non-randomised studies than in randomised trials; and two comparisons had larger estimates of effect in randomised than in non-randomised studies.Five studies found larger estimates of effect in trials with inadequate concealment of allocation than in trials with adequate concealment. The four other studies did not find statistically significant differences.

AUTHORS' CONCLUSIONS

The results of randomised and non-randomised studies sometimes differed. In some instances non-randomised studies yielded larger estimates of effect and in other instances randomised trials yielded larger estimates of effect. The results of controlled trials with adequate and inadequate/unclear concealment of allocation sometimes differed. When differences occurred, most often trials with inadequate or unclear allocation concealment yielded larger estimates of effects relative to controlled trials with adequate allocation concealment. However, it is not generally possible to predict the magnitude, or even the direction, of possible selection biases and consequent distortions of treatment effects from studies with non-random allocation or controlled trials with inadequate or unclear allocation concealment.

Study protocol for the evaluation of an Infant Simulator based program delivered in schools: a pragmatic cluster randomised controlled trial

Background

This paper presents the study protocol for a pragmatic randomised controlled trial to evaluate the impact of a school based program developed to prevent teenage pregnancy. The program includes students taking care of an Infant Simulator; despite growing popularity and an increasing global presence of such programs, there is no published evidence of their long-term impact. The aim of this trial is to evaluate the Virtual Infant Parenting (VIP) program by investigating pre-conceptual health and risk behaviours, teen pregnancy and the resultant birth outcomes, early child health and maternal health.

Methods and Design

Fifty-seven schools (86% of 66 eligible secondary schools) in Perth, Australia were recruited to the clustered (by school) randomised trial, with even randomisation to the intervention and control arms. Between 2003 and 2006, the VIP program was administered to 1,267 participants in the intervention schools, while 1,567 participants in the non-intervention schools received standard curriculum. Participants were all female and aged between 13-15 years upon recruitment. Pre and post-intervention questionnaires measured short-term impact and participants are now being followed through their teenage years via data linkage to hospital medical records, abortion clinics and education records. Participants who have a live birth are interviewed by face-to-face interview. Kaplan-Meier survival analysis and proportional hazards regression will test for differences in pregnancy, birth and abortion rates during the teenage years between the study arms.

Discussion

This protocol paper provides a detailed overview of the trial design as well as initial results in the form of participant flow. The authors describe the intervention and its delivery within the natural school setting and discuss the practical issues in the conduct of the trial, including recruitment. The trial is pragmatic and will directly inform those who provide Infant Simulator based programs in school settings.

Trial registration

ISRCTN24952438

Reported effects in randomized controlled trials were compared with those of nonrandomized trials in cholecystectomy

OBJECTIVES

Because external validity of randomized controlled trials (RCTs) may be insufficient, the performance of nonrandomized controlled trials (nRCTs) is increasingly debated. RCTs and nRCTs were compared using the example of laparoscopic vs. open cholecystectomy (LC vs. OC).

STUDY DESIGN AND SETTING

RCTs and nRCTs comparing LC and OC were identified by searching PubMed. To assess internal and external validity of the studies, patient characteristics, relative risks, and mean differences of RCTs and nRCTs were compared by meta-analytic techniques.

RESULTS

In total, 162 studies were analyzed (136 nRCTs and 26 RCTs). Significant discrepancies between RCT- and nRCT-based results were revealed for 3 of 15 variables: overall complications (P<0.021), wound infections (P<0.014), and length of hospital stay (P<0.005). In RCTs and in nRCTs, length of hospital stay and return to work were significantly reduced when using LC compared with OC. The results of nRCTs were more often heterogeneous among themselves (11 of 15) as compared with RCTs (4 of 15).

CONCLUSION

The results of RCTs and nRCTs differ significantly in at least 20% of the variables. External validities of RCTs and nRCTs in LC vs. OC appear to be similar. Between-study heterogeneity was larger in nRCTs than in RCTs of cholecystectomy.

SUPPORT Tools for evidence-informed health Policymaking (STP) 17: Dealing with insufficient research evidence

This article is part of a series written for people responsible for making decisions about health policies and programmes and for those who support these decision makers.

In this article, we address the issue of decision making in situations in which there is insufficient evidence at hand. Policymakers often have insufficient evidence to know with certainty what the impacts of a health policy or programme option will be, but they must still make decisions. We suggest four questions that can be considered when there may be insufficient evidence to be confident about the impacts of implementing an option. These are: 1. Is there a systematic review of the impacts of the option? 2. Has inconclusive evidence been misinterpreted as evidence of no effect? 3. Is it possible to be confident about a decision despite a lack of evidence? 4. Is the option potentially harmful, ineffective or not worth the cost?

Principles of designing a cohort study in orthopaedics

A well-designed and executed prospective cohort study can provide high-quality evidence in the evaluation of the effectiveness of surgical interventions. In designing a cohort study to evaluate orthopaedic interventions, it is important to recognize the limitations of the design as well as the methodological features that can be incorporated to strengthen the validity of the conclusions. In this article, we discuss the importance of the appropriate selection of participants for a control group, the management of confounders, the selection of outcomes with established measurement properties (reliability, validity, and sensitivity to change), the blinded assessment of outcomes, and the impact of nonparticipants and patients lost to follow-up.

Are there roles for observational database studies and structured quantification of expert opinion to answer therapy controversies in transplants?

Approaches to determine whether one transplant-related therapy is better than another include: (1) using experimental data, such as those from randomized controlled trials (RCTs); (2) using observational data, such as those from observational databases (ODBs) and (3) using conclusions from the structured quantification of expert opinion based on a consideration of evidence from RCTs, ODBs and other sources. Large RCTs are widely and appropriately regarded as the gold standard of clinical investigation. However, data from large RCTs are rarely available for transplant-related therapy questions. We discuss some of the limitations of RCTs in the transplant setting often including small size and short follow-up. These limitations are only partly solved by meta-analyses of RCTs. Data from high-quality ODBs are not only often useful in this setting but also have limitations. Biases may be difficult or impossible to identify and/or adjust for. However, ODBs have large numbers of diverse subjects receiving diverse therapies and analyses that often give answers more useful to clinicians than RCTs. Side-by-side comparisons suggest analyses from high-quality ODBs often give similar conclusions to meta-analyses of high-quality RCTs. Meta-analyses combining data from RCTs and ODBs are sometimes appropriate. Quantitation of expert opinion, when of high quality, is also useful: experts rarely disagree under precisely defined circumstances and their consensus conclusions are often concordant with results of high-quality RCTs and ODBs. We suggest increased use of ODBs and expert opinion as reliable and effective ways to determine relative efficacies of new therapies in transplant settings.

Association of conventional goals and perceptions of pregnancy with female teenagers' pregnancy avoidance behavior and attitudes

CONTEXT

Fostering conventional goals is a key component of pregnancy prevention interventions for teenagers. However, research has not shown whether having goals independently influences sexual behavior, or whether the perception that pregnancy represents an impediment to achieving goals mediates any association.

METHODS

In 1999-2001, a racially mixed group of 351 sexually experienced female teenagers who were inadequate contraceptive users completed surveys about goals, the anticipated impact of childbearing on these goals, and protective behaviors and attitudes. Chi-square, regression and two-by-two table analyses assessed associations between goals and perceptions of early childbearing and pregnancy avoidance measures.

RESULTS

Three-fourths of respondents had educational or vocational goals. Eight in 10 of these teenagers perceived their goals to be achievable, but fewer than half thought pregnancy would be an impediment to achieving these goals. Teenagers who had goals were more likely than others to have used a contraceptive at last intercourse (odds ratio, 1.9), but controlling for the perception of pregnancy as an impediment eliminated this association. In contrast, considering pregnancy an impediment was associated with an increased likelihood of supporting each pregnancy avoidance measure (2.1-9.6), and of intending to avoid pregnancy and to have an abortion if pregnant, regardless of whether teenagers had goals (8.3-13.8).

CONCLUSIONS

Conventional goals appear to motivate teenagers to avoid getting pregnant only if they believe pregnancy will be an impediment. Thus, it may be less important to encourage young women to formulate goals than to ensure that they consider adolescent childbearing a threat to their plans.

Differences in pregnancy desire among pregnant female adolescents at a state-funded family planning clinic

We wished to examine variables associated with pregnancy desire among pregnant adolescents from low socioeconomic backgrounds. This study analyzed 335 charts at a state-funded family planning clinic. Participants were adolescents who had a positive pregnancy test at the clinic on the day of the survey. Logistic regression was utilized to determine differences in pregnancy desire. We found that Hispanic teens were more than twice as likely to desire pregnancy as African American teens (adjusted odds ratio [AOR], 2.22; 95% confidence interval [CI], 1.22-3.65), and adolescents who were not in school were almost twice as likely as those who were in school full-time to desire pregnancy (AOR, 1.83; 95% CI, 1.08-3.09). Hispanic teens who were not in school were 12 times more likely to desire pregnancy than African American teens who were in school full-time (odds ratio [OR], 11.47; 95% CI, 3.68-35.75). Adolescent pregnancy desire is significantly associated with educational status and racial background. Developing culturally appropriate interventions to encourage continued education and asking about community and familial norms are essential steps in addressing this issue.

A process for systematically reviewing the literature: providing the research evidence for public health nursing interventions

BACKGROUND

Several groups have outlined methodologies for systematic literature reviews of the effectiveness of interventions. The Effective Public Health Practice Project (EPHPP) began in 1998. Its mandate is to provide research evidence to guide and support the Ontario Ministry of Health in outlining minimum requirements for public health services in the province. Also, the project is expected to disseminate the results provincially, nationally, and internationally. Most of the reviews are relevant to public health nursing practice.

AIMS

This article describes four issues related to the systematic literature reviews of the effectiveness of public health nursing interventions: (1) the process of systematically reviewing the literature, (2) the development of a quality assessment instrument, (3) the results of the EPHPP to date, and (4) some results of the dissemination strategies used.

METHODS

The eight steps of the systematic review process including question formulation, searching and retrieving the literature, establishing relevance criteria, assessing studies for relevance, assessing relevant studies for methodological quality, data extraction and synthesis, writing the report, and dissemination are outlined. Also, the development and assessment of content and construct validity and intrarater reliability of the quality assessment questionnaire used in the process are described.

RESULTS

More than 20 systematic reviews have been completed. Content validity was ascertained by the use of a number of experts to review the questionnaire during its development. Construct validity was demonstrated through comparisons with another highly rated instrument. Intrarater reliability was established using Cohen's Kappa. Dissemination strategies used appear to be effective in that professionals report being aware of the reviews and using them in program planning/policymaking decisions.

CONCLUSIONS

The EPHPP has demonstrated the ability to adapt the most current methods of systematic literature reviews of effectiveness to questions related to public health nursing. Other positive outcomes from the process include the development of a critical mass of public health researchers and practitioners who can actively participate in the process, and the work on dissemination has been successful in attracting external funds. A program of research in this area is being developed.

Randomisation to protect against selection bias in healthcare trials

BACKGROUND

Randomised trials use the play of chance to assign participants to comparison groups. The unpredictability of the process, if not subverted, should prevent systematic differences between comparison groups (selection bias), provided that a sufficient number of people are randomised.

OBJECTIVES

To assess the effects of randomisation and concealment of allocation on the results of healthcare trials.

SEARCH STRATEGY

We searched the Cochrane Methodology Register, MEDLINE, SciSearch, reference lists up to August 2000 and used personal communication.

SELECTION CRITERIA

Cohorts of trials, systematic reviews or meta-analyses of healthcare interventions that compared outcomes or prognostic factors for one of the following comparisons: randomised versus non-randomised trials, randomised trials with adequately versus inadequately concealed allocation, or high versus low quality trials where selection bias could not be separated from other sources of bias.

DATA COLLECTION AND ANALYSIS

One of us went through all of the citations in the Cochrane Methodology Register and accumulated reference lists. Studies that appeared to meet the inclusion criteria were retrieved and assessed independently by two of the reviewers. The methodological quality of included studies was appraised and information extracted by one of us and checked by a second. Tabular summaries of the results were prepared for each comparison and the results across studies were assessed qualitatively to identify common trends or discrepancies.

MAIN RESULTS

We identified 32 studies including over 3000 trials. Twenty-two studies compared randomised versus non-randomised trials, three compared adequately versus inadequately concealed allocation, and nine compared high versus low quality trials (some studies included more than one comparison). Five studies were of high methodological quality. In 15 of the 22 studies that compared randomised and non-randomised trials of the same intervention, important differences were found in the estimates of effect. Some of these differences were due to a poorer prognosis in the control groups in the non-randomised trials. The results of the other seven studies that compared randomised and non-randomised trials across different interventions are less clear. Comparisons of adequately and inadequately concealed allocation in randomised trials of the same intervention provided high quality evidence that concealment can be crucial in achieving similar treatment groups and, therefore, unbiased estimates of treatment effects. Studies with inadequate concealment tended to overestimate treatment effects. Comparisons of high and low quality trials of the same intervention have found important differences in estimates of effect, but it is not possible to determine the extent to which these differences can be attributed to randomisation or concealment of allocation. Omitting comparisons between randomised trials and non-randomised trials using historical controls did not substantially alter the results or conclusions of our review.

AUTHORS' CONCLUSIONS

On average, non-randomised trials and randomised trials with inadequate concealment of allocation tend to result in larger estimates of effect than randomised trials with adequately concealed allocation. However, it is not generally possible to predict the magnitude, or even the direction, of possible selection biases and consequent distortions of treatment effects.

Impact of a theoretically based sex education programme (SHARE) delivered by teachers on NHS registered conceptions and terminations: final results of cluster randomised trial

OBJECTIVE

To assess the impact of a theoretically based sex education programme (SHARE) delivered by teachers compared with conventional education in terms of conceptions and terminations registered by the NHS.

DESIGN

Follow-up of cluster randomised trial 4.5 years after intervention.

SETTING

NHS records of women who had attended 25 secondary schools in east Scotland.

PARTICIPANTS

4196 women (99.5% of those eligible).

INTERVENTION

SHARE programme (intervention group) v existing sex education (control group).

MAIN OUTCOME MEASURE

NHS recorded conceptions and terminations for the achieved sample linked at age 20.

RESULTS

In an "intention to treat" analysis there were no significant differences between the groups in registered conceptions per 1000 pupils (300 SHARE v 274 control; difference 26, 95% confidence interval -33 to 86) and terminations per 1000 pupils (127 v 112; difference 15, -13 to 42) between ages 16 and 20.

CONCLUSIONS

This specially designed sex education programme did not reduce conceptions or terminations by age 20 compared with conventional provision. The lack of effect was not due to quality of delivery. Enhancing teacher led school sex education beyond conventional provision in eastern Scotland is unlikely to reduce terminations in teenagers.

TRIAL REGISTRATION

ISRCTN48719575 [controlled-trials.com].

Teen Contraceptive Decisions: Childbearing Intentions Are the Tip of the Iceberg

OBJECTIVE

To validate a model we developed while trying to understand why pregnant teens so often report that they did not want to become pregnant and could have obtained contraceptives before they conceived.

METHOD

The study enrolled a racially/ethnically diverse group of 351 teenagers. Participants completed a questionnaire that asked about teen pregnancy risk factors, the expected effects of childbearing, the desire to remain non-pregnant, deterrents to contraceptive use, and contraceptive plans.

RESULTS

Most participants were capable of using contraceptives but at high risk for unintended conception because they exhibited numerous sociodemographic risk factors, were unsure that pregnancy would affect their lives adversely, and were ambivalent about remaining non-pregnant. Believing a boyfriend wanted a baby and the anticipated effect of childbearing on 5 specific aspects of life explained 63% of the variance in the desire to remain non-pregnant, which, in conjunction with fears about using contraceptives, explained 20.5% of the variance in future contraceptive plans.

CONCLUSIONS

Our new findings that expectations about the effect of childbearing explain the desire to remain non-pregnant may well help providers determine why teenagers who do not plan to conceive are often willing to allow themselves to do so by default. Further research is needed, as the model did not explain contraceptive decision-making adequately.

Why lightning strikes twice: postpartum resumption of sexual activity during adolescence

PURPOSE

To describe the circumstances surrounding the postpartum resumption of sexual activity in a cohort of teenage mothers. The goal was to shed new light on the reasons why teenagers who have just given birth put themselves at risk for conception.

METHODS

A racially and ethnically diverse group of 267 poor, predominantly unmarried, primiparous, 13-21 year olds was enrolled consecutively at delivery and followed through the third postpartum month. The primary outcome measure was weeks postpartum at resumption of sexual activity, further categorized as protected or unprotected. The analysis controlled for factors thought to influence the postpartum resumption of sexual activity among adult couples and the use of contraception during adolescence. The Kaplan-Meier method was used to estimate the time to end point and Cox proportional-hazards regression analysis to compute relevant relative risks (RR).

RESULTS

By the end of the third postpartum month, 58% of the teenagers had had sexual intercourse and the majority (80%) used contraception when they did so. The median time to first coitus, 10.7 weeks, was unrelated to contraceptive use but was significantly shorter among teenagers who lived with their boyfriends (RR: 2.4; 95%CI: 1.7-3.4) and those who delivered prior to term (RR: 2.1; 95%CI: 1.3-3.6). The analysis revealed that the teenagers who did not use contraception at first postpartum sexual intercourse exhibited more theorized risk factors for conception than those who did and those who remained sexually abstinent.

CONCLUSIONS

This new empirical evidence that coital activity resumes soon after delivery should dispel the normative belief that contraception is unnecessary during the puerperium. Early contraceptive vigilence may also decrease the frequency and rapidity with which teen mothers conceive, as the differences in the prevalence of teen pregnancy risk factors we uncovered suggest that decisions about using contraception (not sexual intercourse) determine the risk of rapid repeat conception. Teens with live-in boyfriends and premature babies are especially apt to benefit from the new information in this report as they resume sexual activity sooner than their peers and are less apt to use contraception when they do so.

Adolescent pregnancy: do expectations affect intentions?

OBJECTIVE

To establish the relationship between expectations about the effects of childbearing on specific aspects of life and the strength of the desire to remain nonpregnant during adolescence. We hypothesized that the absence of negative childbearing expectations is associated with an increase in the odds that sexually active, inadequately contracepting teenage girls are cognitively susceptible to conception.

METHOD

A racially and ethnically diverse group of 351 nulligravida, inadequately contracepting teenagers was studied. Participants responded to 60 items that asked about their expectation about the effects of becoming pregnant and not doing so. Analyses were performed to determine the factorial structure of the childbearing expectations items and their relationship to cognitive susceptibility to conception, defined as the lack of desire to remain nonpregnant.

RESULTS

The analysis yielded a 9-factor solution for the childbearing expectations items. All 9 sub-scales exhibited acceptable reliability coefficients, stable factor patterns, and correlated significantly with the desire to remain nonpregnant. A dose-dependent relationship suggestive of causality was also apparent. In stepwise regression the sub-scales that assessed the anticipated effect of childbearing on future plans, self-esteem, and boyfriend relations remained significant and accounted for 56% of the variance in the desire to remain nonpregnant. The lengthy research instrument was reduced to an 8-item screening tool without loss of psychometric integrity or explanatory power.

CONCLUSIONS

Childbearing expectations reflect distinct concepts and account for a significant portion of the variance in the desire to remain nonpregnant during adolescence. Thus the 8-item screening tool we validated might be used to formulate a differential diagnosis for the enigmatic behavior of teens who say they do not "want" to become pregnant but do not "mind" doing so enough to try to avoid conceiving by default.

The MEMA kwa Vijana Project: Design of a community randomised trial of an innovative adolescent sexual health intervention in rural Tanzania

BACKGROUND

Effective interventions to reduce the incidence of HIV, other sexually transmitted infections (STIs) and unwanted pregnancy among adolescents in sub-Saharan Africa are urgently needed. This paper describes the rationale and design of a randomised trial of the impact of an innovative sexual health intervention among adolescents in rural Mwanza Region, Tanzania.

METHODS

The MEMA kwa Vijana intervention comprises a teacher-led, peer-assisted sexual health education programme for students in the last 3 years of primary school, training and supervision of health workers in the provision of youth-friendly health services, peer condom promotion and distribution, and wider community activities. Detailed process evaluation was conducted and the impact of the intervention was evaluated through a community-randomised trial in which a cohort of 9645 adolescents was followed up for 3 years. Both process and impact evaluation used multiple assessment methods. Impact measures included incidence and prevalence of HIV and other STIs, pregnancy rates, knowledge and reported attitudes and sexual behaviour, as well as qualitative assessments.

RESULTS

Results of the baseline survey of the cohort have been presented previously. The outcome of the trial will be reported separately.

CONCLUSIONS

Behaviour change interventions among adolescents have been widely advocated, but there have been few rigorously designed trials of their effectiveness, particularly in developing countries, and measurement of sexual behaviour is particularly problematic in this age group. The MEMA kwa Vijana trial was undertaken to address these problems and to collect rigorous evidence on the effectiveness of an innovative intervention, designed to be implemented on a very large scale.

Adolescent pregnancy prevention: An abstinence-centered randomized controlled intervention in a Chilean public high school

PURPOSE

To evaluate the efficacy of an abstinence-centered sex education program in adolescent pregnancy prevention, the TeenSTAR Program was applied in a high school in Santiago, Chile.

METHODS

A total of 1259 girls from a Santiago high school were divided into three cohorts depending on the year they started high school: the 1996 cohort of 425 students, which received no intervention; the 1997 cohort, in which 210 students received an intervention and 213 (control group) did not; and the 1998 cohort, in which 328 students received an intervention and 83 (control group) did not. Students were randomly assigned to control and intervention groups in these cohorts, before starting with the program. We conducted a prospective, randomized study using the application of the TeenSTAR sex education program during the first year of high school to the intervention groups in the 1997 and 1998 cohorts. All cohorts were followed up for 4 years; pregnancy rates were recorded and subsequently contrasted in the intervention and control groups. Pregnancy rates were measured and Risk Ratio with 95% confidence interval were calculated for intervention and control groups in each cohort.

RESULTS

Pregnancy rates for the intervention and control groups in the 1997 cohort were 3.3% and 18.9%, respectively (RR: 0.176, CI: 0.076-0.408). Pregnancy rates for the intervention and control groups in the 1998 cohort were 4.4% and 22.6%, respectively (RR 0.195, CI: 0.099-0.384).

CONCLUSIONS

The abstinence-centered TeenSTAR sex education intervention was effective in the prevention of unintended adolescent pregnancy.

Pupil-led sex education in England (RIPPLE study): cluster-randomised intervention trial

BACKGROUND

Improvement of sex education in schools is a key part of the UK government's strategy to reduce teenage pregnancy in England. We examined the effectiveness of one form of peer-led sex education in a school-based randomised trial of over 8000 pupils.

METHODS

29 schools were randomised to either peer-led sex education (intervention) or to continue their usual teacher-led sex education (control). In intervention schools, peer educators aged 16-17 years delivered three sessions of sex education to 13-14 year-old pupils from the same schools. Primary outcome was unprotected (without condom) first heterosexual intercourse by age 16 years. Analysis was by intention to treat.

FINDINGS

By age 16 years, significantly fewer girls reported intercourse in the peer-led arm than in the control arm, but proportions were similar for boys. The proportions of pupils reporting unprotected first sex did not differ for girls (8.4% intervention vs 8.3% control) or for boys (6.2% vs 4.7%). Stratified estimates of the difference between arms were -0.4% (95% CI -3.7% to 2.8%, p=0.79) for girls and -1.4% (-4.4% to 1.6%, p=0.36) for boys. At follow-up (mean age 16.0 years [SD 0.32]), girls in the intervention arm reported fewer unintended pregnancies, although the difference was borderline (2.3% vs 3.3%, p=0.07). Girls and boys were more satisfied with peer-led than teacher-led sex education, but 57% of girls and 32% of boys wanted sex education in single-sex groups.

INTERPRETATION

Peer-led sex education was effective in some ways, but broader strategies are needed to improve young people's sexual health. The role of single-sex sessions should be investigated further.

Teenage antenatal clinics may reduce the rate of preterm birth: a prospective study

OBJECTIVE

To examine whether teenage antenatal clinics reduce the incidence of preterm birth.

DESIGN

A multicentre prospective study was performed.

SETTING

Three Australian hospitals with maternity services.

POPULATION

Consecutive teenage patients (N= 731) were approached at their first or second antenatal visit.

METHODS

Cases were women attending multidisciplinary teenage antenatal clinics and controls attended general hospital-based antenatal clinics. Teenage antenatal clinics involved multidisciplinary care and included guidelines to screen and treat all patients for infectious and social pathology. General antenatal clinic care was in accordance with Australian standards.

MAIN OUTCOME MEASURES

Preterm birth, newborn biometry adjusted for gestational age, breastfeeding and contraception plans at discharge.

RESULTS

Consent was obtained from 651 (89%) patients. Teenage pregnancy clinic patients were significantly less likely to present with threatened preterm labour (OR 0.45; 95% CI 0.29-0.68), preterm, prelabour, prolonged rupture of membranes (OR 0.34; 95% CI 0.18-0.63) or deliver preterm (OR 0.40; 95% CI 0.25-0.62) compared with those from general clinics. However, there was no independent effect of clinic care upon newborn biometry outcomes. Clinic care did not significantly alter rates of initiation of breastfeeding in hospital. However, significantly more of the teenage antenatal clinic mothers were discharged on contraception (OR 1.58; 95% CI 1.07-2.25).

CONCLUSION

Teenage-specific antenatal clinics may reduce the rate of preterm birth.

A school-based randomized controlled trial of peer-led sex education in England

This article discusses the design of an ongoing cluster-randomized trial comparing two forms of school-based sex education in terms of educational process and sexual health outcomes. Twenty-nine schools in southern England have been randomized to either peer-led sex education or to continue with their traditional teacher-led sex education. The primary objective is to determine which form of sex education is more effective in promoting young people's sexual health. The trial includes an unusually detailed evaluation of the process of sex education as well as the outcomes. The sex education programs were delivered in school to pupils ages 13-14 years who are being followed until ages 19-20. Major trial outcomes are unprotected sexual intercourse and regretted intercourse by age 16 and cumulative incidence of abortion by ages 19-20. We discuss the rationale behind various aspects of the design, including ethical issues and practical challenges of conducting a randomized trial in schools, data linkage for key outcomes to reduce bias, and integrating process and outcome measures to improve the interpretation of findings.

Postnatal home visits in teenage mothers: a randomised controlled trial

BACKGROUND

Teenage pregnancies are associated with negative socioeconomic effects. Our aim was to ascertain whether a postnatal home-visiting service for teenage mothers younger than age 18 years could reduce the frequency of adverse neonatal outcomes and improve knowledge of contraception, breastfeeding, and infant vaccination schedules in this parent group.

METHODS

We enrolled 139 adolescents, attending a teenage pregnancy clinic, in a randomised controlled trial. After completing an antenatal questionnaire designed to assess their knowledge of contraception, infant vaccination, and breastfeeding, we assigned participants to either receive five structured postnatal home visits by nurse-midwives (n=65) or not (n=71). Assessment interviews were done 6 months postpartum. Our primary endpoint was unadjusted difference in knowledge between groups, and incidence of predefined adverse neonatal outcomes. Analysis was by intention to treat.

FINDINGS

Three women withdrew before randomisation because of late fetal loss, 11 mothers withdrew because of adverse neonatal outcomes (adverse neonatal outcome was a primary endpoint, but resulted in withdrawal from the study for knowledge outcomes), and one left voluntarily. Follow-up data were, therefore, available for 124 teenagers. Postnatal home visits were associated with a reduction in adverse neonatal outcomes (intervention: 2; control: 9; relative risk 0.24, 95% CI 0.05-1.08), and a significant increase in contraception knowledge (mean difference 0.92, 95% CI 0.32-1.52). However, there was no significant increase in knowledge with respect to breastfeeding or infant vaccination schedules associated with the home visits.

INTERPRETATION

Postnatal home-visiting services by nurse-midwives reduce adverse neonatal events and improve contraception outcomes, but do not affect breastfeeding or infant vaccination knowledge or compliance.

A cluster randomized trial of a sex education programme in Belize, Central America

BACKGROUND

Concerns about adverse consequences of early childbearing and risk of sexually transmitted diseases (STD) have renewed interest in the sexual behaviour of adolescents in developing countries, where they represent a large proportion of the population and are at highest risk. To date, little is known about the sexual knowledge of adolescents in developing countries. This study's primary objective was to evaluate the effectiveness of a responsible sexuality education programme (RSP) in changing knowledge associated with sex and sexuality; secondary objectives were to evaluate changes in attitudes and behavioural intent.

METHODS

A cluster randomized design randomizing high school classes in Belize City. Subjects were 13-19 years old.

RESULTS

Seven schools in Belize City were selected; 8 classrooms were randomized to the intervention arm and 11 classrooms to the control arm (N = 399). The intervention was associated with two more correct answers on the post-test (difference score was 2.22 points, 95% CI = 0.53, 3.91) after adjusting for gender and previous sexual experience. After controlling for gender and previous sexual experience, the intervention was associated with no change in the attitudes (0.06, 95% CI: -2.89, 2.82) or behavioural intent domains (0.84, 95% CI: -1.12, 2.46).

CONCLUSIONS

Greater changes in knowledge were observed in the intervention group than in the control group following the intervention. Changes were not observed for the attitude or behavioural intent domains. These results and the results of similar studies may be used to further improve sex education programmes as it is imperative that students have access to the information necessary to make informed decisions regarding their sexual health.

Interventions to reduce unintended pregnancies among adolescents: systematic review of randomised controlled trials

OBJECTIVE

To review the effectiveness of primary prevention strategies aimed at delaying sexual intercourse, improving use of birth control, and reducing incidence of unintended pregnancy in adolescents.

DATA SOURCES

12 electronic bibliographic databases, 10 key journals, citations of relevant articles, and contact with authors.

STUDY SELECTION

26 trials described in 22 published and unpublished reports that randomised adolescents to an intervention or a control group (alternate intervention or nothing).

DATA EXTRACTION

Two independent reviewers assessed methodological quality and abstracted data.

DATA SYNTHESIS

The interventions did not delay initiation of sexual intercourse in young women (pooled odds ratio 1.12; 95% confidence interval 0.96 to 1.30) or young men (0.99; 0.84 to 1.16); did not improve use of birth control by young women at every intercourse (0.95; 0.69 to 1.30) or at last intercourse (1.05; 0.50 to 2.19) or by young men at every intercourse (0.90; 0.70 to 1.16) or at last intercourse (1.25; 0.99 to 1.59); and did not reduce pregnancy rates in young women (1.04; 0.78 to 1.40). Four abstinence programmes and one school based sex education programme were associated with an increase in number of pregnancies among partners of young male participants (1.54; 1.03 to 2.29). There were significantly fewer pregnancies in young women who received a multifaceted programme (0.41; 0.20 to 0.83), though baseline differences in this study favoured the intervention.

CONCLUSIONS

Primary prevention strategies evaluated to date do not delay the initiation of sexual intercourse, improve use of birth control among young men and women, or reduce the number of pregnancies in young women.

Limits of teacher delivered sex education: interim behavioural outcomes from randomised trial

OBJECTIVE

To determine whether a theoretically based sex education programme for adolescents (SHARE) delivered by teachers reduced unsafe sexual intercourse compared with current practice.

DESIGN

Cluster randomised trial with follow up two years after baseline (six months after intervention). A process evaluation investigated the delivery of sex education and broader features of each school.

SETTING

Twenty five secondary schools in east Scotland.

PARTICIPANTS

8430 pupils aged 13-15 years; 7616 completed the baseline questionnaire and 5854 completed the two year follow up questionnaire.

INTERVENTION

SHARE programme (intervention group) versus existing sex education (control programme).

MAIN OUTCOME MEASURES

Self reported exposure to sexually transmitted disease, use of condoms and contraceptives at first and most recent sexual intercourse, and unwanted pregnancies.

RESULTS

When the intervention group was compared with the conventional sex education group in an intention to treat analysis there were no differences in sexual activity or sexual risk taking by the age of 16 years. However, those in the intervention group reported less regret of first sexual intercourse with most recent partner (young men 9.9% difference, 95% confidence interval -18.7 to -1.0; young women 7.7% difference, -16.6 to 1.2). Pupils evaluated the intervention programme more positively, and their knowledge of sexual health improved. Lack of behavioural effect could not be linked to differential quality of delivery of intervention.

CONCLUSIONS

Compared with conventional sex education this specially designed intervention did not reduce sexual risk taking in adolescents.

Improving teenagers' knowledge of emergency contraception: cluster randomised controlled trial of a teacher led intervention

OBJECTIVE

To assess the effectiveness of a teacher led intervention to improve teenagers' knowledge about emergency contraception.

DESIGN

Cluster randomised controlled trial.

SETTING

24 mixed sex, state secondary schools in Avon, south west England.

PARTICIPANTS

1974 boys and 1820 girls in year 10 (14-15 year olds).

INTERVENTION

Teachers gave a single lesson on emergency contraception to year 10 pupils. The teachers had previously received in-service training on giving the lesson. The pupils were actively involved during the lesson.

MAIN OUTCOME MEASURES

Questionnaires distributed to pupils at baseline and six months after the intervention assessed their knowledge of the correct time limits for hormonal emergency contraception and for use of the intrauterine device as emergency contraception, the proportion of pupils who were not virgins, the proportion who had used emergency contraception, and the pupils' intention to use emergency contraception in the future.

RESULTS

The proportion of pupils knowing the correct time limits for both types of emergency contraception was significantly higher in the intervention group than in the control group at six months' follow up (hormonal contraception: proportion of boys 15.9% higher (95% confidence interval 6.5% to 25.3%), girls 20.4% (10.4% to 30.4%); intrauterine device used as emergency contraception: boys 4.2% (0.7% to 7.7%), girls 10.7% (0.4% to 21.0%). The number of pupils needed to be taught for one more pupil to know the correct time limits was six for boys and five for girls. The intervention and control groups did not differ in the proportion of pupils who were not virgins, in the proportion who had used emergency contraception, and in the proportion intending to use emergency contraception in the future.

CONCLUSIONS

The intervention significantly improved the proportion of boys and girls knowing the correct time limits for both types of emergency contraception. The intervention did not change the pupils' sexual activity or use of emergency contraception.

Should systematic reviews include non-randomized and uncontrolled studies? The case of acupuncture for chronic headache

We aimed to investigate: (1) whether patient and intervention characteristics, design-independent quality aspects, and response rates differ between randomized and non-randomized trials of acupuncture for chronic headache; (2) whether non-randomized studies provide useful additional information (regarding long-term effects, prognostic factors, adverse effects, and generalizability); (3) reasons for potential differences in response rates. Studies including at least five patients and reporting clinical outcome data were identified through searches in Medline, Embase, the Cochrane Controlled Trials Register, other databases and checking of bibliographies. Twenty-four randomized trials and 35 non-randomized studies (five non-randomized controlled cohort studies, 10 prospective uncontrolled studies, 10 case series, and 10 cross-sectional surveys) met the inclusion criteria. Studies were heterogeneous regarding patients, interventions, outcome measurements and results. On average, randomized trials had smaller sample sizes, met more quality criteria, and had lower response rates (0.59 [95% confidence interval 0.48-0.69] vs. 0.78 [0.72-0.83]). Whether randomized or not, studies meeting more quality criteria had lower response rates. Non-randomized studies did not have significantly longer follow-up periods, three included an analysis of prognostic variables, only one reported on adverse effects, and the degree of generalizability was unclear. In the case of acupuncture for chronic headache, non-randomized studies confirmed the finding of a systematic review of randomized trials that the treatment is likely to be effective but provided little relevant additional information on long-term effects, prognostic factors, and adverse effects.

Personal values and sexual decision-making among virginal and sexually experienced urban adolescent girls

PURPOSE

To guide the development of an intervention to reduce the incidence of sexually transmitted diseases (STDs) in urban, adolescent girls, we investigated such girls' reasons for deciding to have or not to have sexual intercourse.

METHODS

Consecutive girls >or=14 years of age attending an urban adolescent clinic were invited to complete an anonymous survey about sexual decision-making. In this pilot study, girls were asked: (a) whether they agreed with a statement that they had or had not had sexual intercourse "because of my values and beliefs"; and (b) to select from a list one or more specific reasons why they had or had not had intercourse. The girls were categorized by self-report as either "virgins," "currently inactive" (no intercourse in the preceding 3 months), or "currently active" (had intercourse during the preceding 3 months).

RESULTS

Usable surveys were obtained from 197 adolescents whose age (18.2 +/- 2.6 years) and race (69% black) were comparable to those of clinic attendees in general. Forty girls (20%; age 16.1 +/- 2.1 years) were virgins, 25 girls (13%; age 17.8 +/- 2.3 years) were inactive, and 132 girls (67%; age 18.9 +/- 2.5 years) were currently active. "Values and beliefs" were cited as the reason for decisions about sexual behavior by 53% of the virgins, but only by 24% of the sexually inactive and 24% of the sexually active girls (p = .002). Virgins were more likely than inactive girls to cite three specific reasons for not having sex: "not the right thing for me now" (82% vs. 50%, p = .007), "waiting until I am older" (69% vs. 8%, p = .001), and "waiting until I am married" (67% vs. 38%, p = .02). The reason "against my religious beliefs" was cited by 23% of virgins and 13% of inactive girls (p = not significant). Personal values were implicit in the two specific reasons for having sex that active girls chose most frequently, namely, "I like/love the person" (86%) and "I like having sex" (37%), although only 24% of these girls had explicitly cited "values and beliefs" as their reason for having sex.

CONCLUSIONS

Our data indicate that urban girls, both those who have had sexual intercourse and those who have not, view their sexual behavior as being based on personal (although infrequently religious) values. Many of the virginal urban, adolescent girls we surveyed hold abstinence as a personal value. The sexually active adolescents perceive the decision to have sexual intercourse as being based affirmatively on their personal values rather than on the chance occurrence of opportunities to have intercourse. These data may be useful in the development of new strategies for reducing urban adolescent girls' risk of acquiring sexually transmitted diseases.

Adolescent sexuality and pregnancy

The adolescent pregnancy rate has decreased throughout the USA. However, compared with other industrialized countries, US rates remain high. Efforts to decrease the number of teenage pregnancies are centered on sex education, postponing sexual activity, and safe sex practices.