Randomised controlled trials of educational interventions ha
Randomised controlled trials of educational interventions have also reported evidence to support the view that increased education is likely to be protective against infection. However, most education-focused trials are not designed to detect low-probability events such as HIV or to study the cumulative effect of education on HIV infection after students leave school—an important buy RepSox in which exposure is also likely to occur. The next-best option is to look for natural experiments that have led to changes in education that are unrelated to other factors likely to affect HIV status, which can then be evaluated using rigorous econometric methods, such as instrumental variables or regression discontinuity. The latter approach, which so far has been relatively underused in health and medical research, is particularly appealing to identify rule-based or age-based policy changes in the real world. However, examples such as these are rare in low-income countries, either because few policies are adopted or because they are so poorly implemented that they do not lead to any real change. A recent study from Zimbabwe that used such a methodological approach found that maternal education was positively associated with more knowledge of HIV status and the preventive behaviours needed to reduce infection risk. However, owing to a lack of statistical power, the authors were unable to identify the effect of education on HIV status.
In , Jan-Walter De Neve and colleagues present exciting results from an important study of the effect of a policy change that increased access to education among junior high school students in Botswana in 1996. The policy change led to an average increase of 0·8 years of schooling among teenagers who were just young enough to benefit from this policy. Using age-specific exposure to the policy as an instrumental variable, De Neve and colleagues identified increases in education that were unlikely to be correlated with other factors that also affect HIV status and then showed that individuals who gained an additional year of schooling due to the policy were 8·1 percentage points (p=0·008) less likely to test positive for HIV about a decade later, when most of those exposed to the policy were then in their mid-20s. Hence, De Neve and colleagues provide strong and convincing evidence that increased education in Botswana was protective against HIV infection among young adults and is even cost effective by most standards. Their results were strongest among women (11·6 percentage points per extra year, p=0·046), which is especially important given the worldwide inequities in access to secondary schooling for girls, especially in Africa.
Women bear most of the worldwide burden of sexually transmitted infections (STIs) and their resultant morbidity and mortality. However, STIs are only one adverse health threat borne disproportionately by women, who also face important risks related to reproductive health, violence and trauma, economic instability, and other areas. Interventions that aim to mitigate these risks can have substantial public health success, but occasionally interventions inadvertently generate new risks as well. Hormonal forms of contraception, including oral contraceptive pills, progestin-only injectables such as depo-medroxyprogesterone acetate (DMPA), and hormone-containing technologies (implants, intrauterine devices, patches, and rings) are used by more than 150 million women worldwide, and worldwide implementation of safe and effective contraception has had substantial public health effect on prevention of unintended pregnancy and maternal morbidity. Contraceptives, though, are not without risk, and some methods have been associated with increased likelihood of complications, such as thromboembolic disease. Still, when weighed against the substantial health and economic benefits afforded by prevention of unintended pregnancy, the public health balance favours widespread access to a diverse assortment of safe and effective contraceptive methods as a public health imperative.