You would have thought I'd have had enough by now.
The American Journal of Clinical Nutrition-- a big deal journal in the human nutrition world--has just published a paper by the MVP team on "Multisectoral intervention to accelerate reductions in childstunting: an observational study from 9 sub-Saharan African countries". The Conclusion in the Abstract "These findings provide encouraging evidence that a package of multisector interventions has the potential to produce reductions in childhood stunting".
It is such a shame that the impact evaluation design does not allow us to say anything more than that. After all one would be surprised if a multisector package did not have the potential to reduce childhood stunting.
The need to word things so carefully originates from the lack of comparator stunting data from similar communities over the same time period. If we had this we could compare the stunting reductions to see if they are faster in the MVP villages.
The comparison the authors make is:
MVP village declines in stunting over the 2005-6 to 2008-9 period vs stunting declines in those same 9 countries, but at (a) a national level and (b) over the period 1988-2008.
If the authors had data from the same time period and from similar (even better, matched) areas then we could plausibly attribute a certain percent of the declines to the MVP.
So, the paper is not able to say too much.
The data are encouraging in that there is a significant downward trend in stunting in 6 of the 9 sites, but we would expect such a big intervention to have an effect on stunting rates in any case.
The real questions remain: (a) how much of the effect is due to the MVP? and, more fundamentally, (b) what happens after the MVP finishes?