Monday March 9 2015
Condoms can protect against unwanted pregnancies and infection
"Getting a good education could be the best form of contraception for teenagers," The Independent reports after a study of recent data from England found an association between improved GCSE results and lower rates of teenage pregnancy.
Researchers looked at data from England on teenage pregnancy rates between 2004 and 2012. They were particularly interested in whether the increasing use of long-acting reversible contraceptive (LARCs), such as implants or injections, was associated with reduced teen pregnancy rates. It didn't.
What they did find is a link between educational achievement – specifically, more teenagers getting at least five GCSEs and reduced rates of teenage pregnancy. The reason for the link between higher educational attainment and reduced pregnancies was not specifically assessed.
This study cannot tell us whether individual teenagers were having sex or using contraceptives or not. It does not tell us, for example, that LARCs are not effective at preventing pregnancy for the individual using them – they are actually known to be highly effective.
Where did the story come from?
The study was carried out by researchers from Nottingham University. No sources of funding were reported.
It was published in the peer-reviewed journal, Social Science and Medicine.
The Independent's reporting of the study is accurate, although the headline that good education is the best form of contraception shouldn't be interpreted as meaning that better sex education in schools is the key, as this study didn't look at this issue specifically.
What kind of research was this?
This was an ecological study looking at trends in teenage pregnancy rates in England and factors that might contribute towards this.
The researchers say teenage pregnancy rates in England have dropped in recent years, and a number of factors have been suggested as having potentially contributed.
These include the promotion of long-acting reversible contraceptives (LARCs), such as contraceptive implants, injections, and intrauterine devices (IUDs, or "the coil"), for young people. Once in use, these methods do not rely on a woman remembering to use them or having to use them correctly.
Increasing levels of education – particularly in deprived areas – could contribute to this trend by making teenage pregnancy have greater consequences ("opportunity cost"). In other words, young women who are in education are more likely to appreciate the downside of becoming pregnant during their teenage years.
This type of study can identify related patterns of changes in the population and possible contributing factors. The approach is often used to look at the impact of a particular change in policy, for example, or to look for reasons for "real-world" changes. But because it does not look at the behaviour and outcomes of individuals, this type of study cannot definitely link the changes to each other.
What did the research involve?
The researchers obtained data on teenage pregnancy (conception), abortion and birth rates in almost 100 areas in England from 2002 to 2014. They also looked at the patterns of LARC use, educational attainment and other factors over the same period to see if the patterns could be related.
Data came from various sources, including:
- publicly funded family planning clinics in 97 areas in England from 2004 to 2012
- the Office for National Statistics – conception, abortion and birth rates, and unemployment rates for women under 20
- the Department of Health – teenage women provided with LARCs at NHS community contraceptive clinics, the number of family planning clinic sessions aimed at young people, the rate of children aged 15 to 17 in care, and the presence of pharmacy schemes to provide emergency birth control
- Public Health England – rates of GP prescriptions for LARCs and the rate of under-18s admitted to hospital with alcohol-related conditions
- the Department of Education – GCSE results and non-white teenage population information
- teenage pregnancy co-ordinators – the presence of pharmacy schemes to provide emergency birth control
The researchers used statistical analysis to look at whether the areas in England that promoted LARCs the most had greater reductions in teenage pregnancy, and similarly whether the other factors had an effect.
What were the basic results?
The researchers found that:
- teenage pregnancy rates in England started to drop in 2008 and continued to decrease up to 2012
- the percentage of teenagers using LARCs more than doubled from 6% in 2004 to around 15% in 2012, while the proportion provided with condoms reduced by more than 10%
- the percentage of 16- and 17-year-olds staying in full-time education has increased significantly
- the proportion of non-white individuals aged 15 to 17 years increased from just over 11% in 2004 to more than 16% in 2012
- alcohol use in the past week among 11- to 15-year-olds decreased from 23% in 2004 to 10% in 2012
In their statistical analysis, the researchers found that although the promotion of LARCs was associated with a slightly reduced level of teenage pregnancies, this link was not large enough to be statistically significant.
Changes in alcohol consumption among teenagers were also not found to be associated with changes in teenage pregnancy rates. There was a statistically significant association between better educational performance and reduced teenage pregnancy.
According to the researchers' statistical model, a 10% increase in the proportion of teenagers receiving five or more GCSE qualifications at grade C or above was associated with an 8% reduction in teenage pregnancy.
They say that as the proportion of teenagers achieving these GCSE grades has increased by about 50% since 2004, this could explain a lot of the decrease seen in teenage pregnancies in this period.
In addition, a 10% increase in the non-white teenage population was associated with about a 2% reduction in teenage pregnancies. The trends in an increasing non-white teenage population and improving GCSE attainment were similar, suggesting the two factors could be related.
The researchers found broadly similar results if they did their analyses in different ways – for example, if they looked at under-16s and older teenagers separately. In these analyses, there was some evidence that the promotion of LARCs had more of an effect in areas with the poorest educational outcomes, but the effects were still small.
How did the researchers interpret the results?
The researchers concluded that the promotion of LARCs has had a generally small and non-significant impact on teenage pregnancy rates in England.
However, they say that, "Improvements in educational achievement and, to a lesser extent, increases in the non-white proportion of the population, are associated with large and statistically significant reductions in teenage pregnancy."
This ecological study has found that the reduction in teenage pregnancy rates in England shows stronger links with increasing educational attainment than with the promotion of long-acting reversible contraceptives (LARCs).
This research aims to identify factors contributing to a real-world phenomenon (reduction in teenage pregnancies) by looking at trends in these factors and this outcome over time, and in different areas.
While this may uncover potential links at a population level, the study cannot definitively say that this is cause and effect, as other unmeasured factors may be playing a role.
For some factors, the study had to use measures that may not fully capture their effects. For example, alcohol use was assessed using the rate of hospital admissions with alcohol-related causes for under-18s, which is unlikely to fully capture alcohol use.
In addition, the study also does not have data on the behaviours and outcomes for individual teenagers. This means the research is not able to say, for example, whether individual teenagers were having sex or using contraceptives or not.
The results should also not be interpreted as meaning that LARCs are not effective at preventing pregnancy – they are actually known to be highly effective.
It is also difficult to interpret the reasons behind the links between higher educational attainment and reduced pregnancies. It's possible the link is being influenced by confounding factors (such as socioeconomic and lifestyle differences) and is not necessarily a direct effect of education.
If it is an effect of education, it is also not possible to say based on this study whether a particular curriculum or educational content has an effect, as this was not looked at. For instance, these findings shouldn't be interpreted as meaning that better sex education in schools is the key.
The researchers note that their study's findings need to be confirmed in other studies in other settings using other study designs, such as randomised controlled trials.
This type of research can give an idea of what effect new policies have on outcomes in real-world settings, and may suggest ways of improving outcomes. But these also need to be tested to identify their effects.
Still, the suggestion that better education for young people could also lead to less teenage pregnancy is a welcome one.
For more information about the range of contraceptive methods available, visit our Contraception guide.
Analysis by Bazian. Edited by NHS Choices. Follow Behind the Headlines on Twitter. Join the Healthy Evidence forum.