This review found that programmes with parental involvement could modify parent-child communication and sexual behaviour of adolescents, but there was a paucity of rigorous studies. The authors' cautious conclusions about the evidence are likely to be reliable.

To assess the effectiveness of interventions with parents or caregivers that were intended to improve the sexual health of children in their care.

Eleven electronic databases including CINAHL, MEDLINE and PsycINFO were searched to 2009 for relevant studies; search terms were reported. The reviewers searched for unpublished studies by checking Open Grey, Google Scholar, Centre for Disease Control websites, the Alan Guttmacher Institute, The National Campaign to Prevent Teen Pregnancy, and Child Trends. The reviewers contacted researchers for information on unpublished studies.

Primary studies were eligible if they had interventions with parental involvement and outcomes related to the sexual health of the parents' children. Outcomes could be sexual behaviours, unwanted sexual outcomes or proxy indicators such as sexual health knowledge and cognitions, or parent-child communication on sexual activity. A range of study designs were eligible but all studies were required to present baseline and follow-up data.

Most of the studies were conducted in the USA. Interventions included one-to-one support, workshops, homework assignments, videos, written material and media messages. Interventions were undertaken in secondary schools, in the community, at college/tertiary institutions, home-based with videos and mass media interventions; some studies were specifically for parents of children with learning disabilities. The parenting component in most of the interventions was aimed at improving parent-child communication about sex; other intervention programmes provided education on sexual and reproductive health, information and children's future values or future plans, values and regulation of the child's behaviour and parental modelling of appropriate behaviour. The outcomes evaluated included parent-child communication about sex, parental monitoring, sexually transmitted infections and pregnancy, and the sexual knowledge, attitudes, intentions, self-efficacy and behaviour of adolescents.

Two reviewers performed the study selection.

The reviewers did not state they assessed methodological quality.

Data were extracted using standard data extraction forms , and the results were tabulated. Study authors were contacted for additional information when necessary.

Two reviewers extracted data which was checked for accuracy by a third.

The results were summarised in a narrative synthesis and stratified by the setting in which the interventions took place.

Forty-four studies were included in the review; 25 randomised controlled trials, 12 non-randomised studies and seven pre- and post-test studies. Follow-up varied from immediately post-intervention to four years.

Secondary school-based interventions (16 studies): Four of six abstinence-based programmes, and five of seven comprehensive programmes were found to improve parent-child communication. Five secondary school programmes reported reductions in sexual risk behaviour.

Community-based programmes (15 studies): Improvements in parent-child communication were reported in all 11 interventions and in knowledge and/or attitudes in eight interventions and reductions in sexual behaviour were reported in five programmes from a total of seven programmes which included four randomised controlled trials.

College-based programmes (two studies): Participating parents in one programme were more ready and skilled to discuss sexual issues than the parents in a control group after a two-hour session. The second study found increased parent-child communication after a 42-hour programme for undergraduate parents of children aged five years and over. None of these programmes involved the children directly.

Home-based audio or visual programmes (four studies): Improvements were found in the young peoples' knowledge, skills and/or attitudes in four programmes, but not in sexual behaviour in the three programmes that examined this outcome.

Media programmes (three studies): Improvements were identified in parent-child communication in two programmes and in young peoples' knowledge and/or attitudes in the two programmes measuring this outcome. Improvements in sexual behaviour were reported in the one programme in which this was measured.

Programmes for parents of children with learning disabilities (three studies):Improvements on several parenting measures were found in one study. Further results were presented in the paper.

Some interventions with intensive parental involvement could modify the sexual behaviour of adolescents, but evidence in the review was limited by a lack of rigorous evaluations in included studies.

The review addressed a clear question and criteria for the inclusion of studies in the review were defined. A range of appropriate electronic databases were searched for relevant studies. Attempts were also made to identify unpublished studies. Steps were taken to minimise reviewer errors and biases for study selection and data extraction.

Methodological quality was not formally assessed, but the authors made some judgments about the methodological rigour of the included studies on the basis of study type. The authors' decision to summarise the results in a narrative synthesis appeared to be justified because of the clinical heterogeneity in populations, interventions, outcomes and evaluation measures. The authors stated the attitudinal and behavioural outcomes were self-reported which meant the results for these outcomes were subject to various reporting biases. The limitations of the review were acknowledged by the authors about the lack of rigorous evaluations of interventions, short follow-up durations and potential limits of generalisation of results to populations outside of the USA.

In general, the authors' cautious conclusions regarding the evidence are likely to be reliable.

Practice: The authors stated that future interventions that involve parents in improving the sexual health of their children should focus developing greater parent-child attachment or connectedness, improve parental monitoring and regulation of behaviour, help parents communicate their own values about sexual behaviour and encourage parents to model the behaviours they want their children to follow.

Research: The authors stated that further research should use experimental designs incorporating a range of measurements to evaluate change, sexual health outcomes, with large sample sizes, detailed parental involvement and follow-up periods of at least two years.

UK Medical Research Council as part of the Sexual Health and Families Programme.