Two surprise results from India’s biggest trialBMJ 2013; 346 doi: http://dx.doi.org/10.1136/bmj.f1796 (Published 20 March 2013) Cite this as: BMJ 2013;346:f1796
In one of the biggest trials ever completed, vitamin A supplements failed to prevent deaths among preschool children in rural north India. The headline result was a surprise in this moderately deficient population, and the researchers spent years checking their data before finally putting it in print. Children in areas that were randomised to administer supplements every six months had almost the same death rate as those living in control areas (estimated mortality 2.5% v 2.6%; mortality ratio 0.96, 95% CI 0.89 to 1.03). Pooled analyses from eight previous trials had led researchers to expect a quarter fewer deaths in supplemented children and they can’t easily explain the discrepant result. Their trial comprised roughly two million children and contributed twice as much statistical power as all other trials put together.
Either vitamin A doesn’t work or doesn’t work half as well as we believe it should, says a linked editorial (doi:10.1016/S0140-6736(13)60600-5). It’s hard to say which at this stage, and the seven year delay before full publication hasn’t helped. The same trial reported a second unexpected result—regular deworming with albendazole didn’t reduce mortality either, or help preschool children gain weight.
Results from both interventions have important policy implications for India and elsewhere, says the editorial. Publication delays were partly due to lack of resources, and funders must invest more heavily in these ambitious trials so researchers can publish promptly.
Cite this as: BMJ 2013;346:f1796