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The latest evidence for practice

Una Adderley
Specialist Nurse
Team Leader

What are the most effective interventions for preventing unplanned adolescent pregnancies?
In the UK there is evidence to suggest that the age of first sexual intercourse is becoming lower and the incidence of sexually transmitted infections is increasing. Strategies to reduce unplanned teenage pregnancy, such as education and improved access to contraceptives, have not yet been highly successful. This Cochrane systematic review sought to evaluate the effectiveness of the different strategies in preventing unplanned pregnancies among adolescents.

The review sought randomized, controlled trials (RCTs) that evaluated any interventions to increase knowledge and affect attitudes to unintended pregnancy, to promote delay in the initiation of sexual activity and to encourage consistent use of contraception in adolescents aged between 10 and 19.

A total of 41 RCTs met the inclusion criteria, which looked at 95,662 ethnically diverse adolescents from mainly industrialised countries and lower socio-economic groups. The results showed that multiple interventions, where education and contraceptive interventions were offered together, were effective in lowering the incidence of unintended
teenage pregnancies.

A commentary notes that this review, to some extent, addresses the concerns of the external steering group of the British National Strategy for Sexual Health and HIV that school sex education programmes are not effective in preventing teenage pregnancies. However, the authors acknowledge that there are limitations to the conclusions that can be drawn, such as the complexity of human sexual behaviour. The review concludes that combined approaches appear to have a positive effect in reducing teenage pregnancies.

Oringanje C, Meremikwu MM, Eko H et al. Interventions for preventing unintended
pregnancies among adolescents. Cochrane Database Syst Rev 2009:CD005215.

Grigg E. Evid Base Nurs 2010;13(1):5-6.

How safe and effective are flu vaccinations for the elderly?

The flu vaccination campaign is fast approaching and the pressure is on to offer vaccination to as many people as possible within the “at-risk” groups. People over 65 form a significant part of this patient population, and this group is particularly at risk of complications, hospital admissions and death from flu. However, there was limited knowledge about the vaccination for this particular age group. This Cochrane systematic review sought to evaluate the effectiveness of vaccination in this age group along with the types and frequency of adverse events.

The review sought RCTs, quasi-RCTS, cohort and case-control studies that had assessed the efficacy of influenza vaccines against influenza infection. A total of 75 studies were identified. However, only one of these was an RCT and it was insufficiently powered to detect any effect on complications. This combined with the lack of RCTs meant that the researchers were unable to reach any clear conclusions.

A commentary notes that vaccine research is highly complicated, due to the difficulty in defining which outcomes should be measured, how “flu” should be defined and the wide array of research approaches that can be used to study this subject. The commentary notes the usefulness of achieving herd immunity to reduce the risk of flu to the population.

It also noted that many adverse events (sometimes mistakenly referred to as “side-effects”), such as local tenderness and fever, may, in fact, be positive evidence that the immune system has been stimulated. The commentator concludes that, although the authors were unable to deliver an overall conclusion, the literature includes good evidence of the general benefits of flu vaccination.

Jefferson T, Di Pietrantonj C, Al-Ansary LA et al. Vaccines for preventing influenza in the elderly. Cochrane Database Syst Rev 2010;2:CD004876.

Pursell E. Evid Base Nurs 2010;13(3):72.