It appears to be another all-IHME special at the Lancet this week. Don’t get me wrong – I am not complaining – I generally really enjoy these articles, and they always give me something interesting to blog about!
I blogged about the fungibility of health aid flows last week, and now they have released another report looking at the declines in the maternal mortality ratio globally from 1980-2008. For those who are not familiar with this metric, the maternal mortality ratio are the number of deaths of the mother per 100,000 live births. There is a general perception out there that the maternal mortality ratio has not declined substantially since the early 1980s, and this new article by the crowd at IHME argues that there has been somewhat more progress (albeit that much more) than originally assumed by most.
Unlike earlier estimates, Hogan et al. have estimated that the number of maternal deaths has declined from 526,00 in 1980 to 343,000 in 2008 while the maternal mortality ratio declined from 422 to 251 in 2008 – representing about a 1.5% decline annually over the entire time period. These are more optimistic estimates than those produced a few years ago by another set of excellent researchers, giving some hope that more progress towards achieving maternal mortality reductions have been made than previously believed.
The challenge here is that data for maternal mortality is particularly bad. I know I complain a lot about most data used in global health, but here we can really say it is total rubbish in many cases. In fact, even in the new estimates there are approximately 21 countries in the sample for which we have no estimates due to the lack of data sources. The innovation from the Murray group is that they managed to use more data sources, applied more standard approaches to correct differences in reporting and other biases, and have used a somewhat more realistic modeling strategy to account for changes. It should be noted, however, these are still just estimates. These figures cannot be compared to figures produced elsewhere and therefore are only as good as the model and estimates made by these researchers.
What might explain the discrepancies between what the IHME and other researchers have found? Have we really made that much more progress against maternal mortality? The answer appears to be both yes and no.
Looking quickly at some of the estimates, it seems that there has been more progress in high population places in than the other researchers had estimated. For example, the IHME estimates that the MMR in India in 2008 was 254 whereas the previous estimates were for 450 in 2005. This is a big difference and given how big India is, this difference alone may explain a bit part of the discrepancies between the estimates. Similarly, Nigeria (608 vs. 1100), Ethiopia (590 vs.720) and Bangladesh (338 vs. 570) are all large population countries with substantially lower new estimates. But the new estimates are higher in some countries, for example the United States (17 vs. 11). So the direction of the difference does appear to be driven by differences in data and estimation strategies across the board.
The bad news, however, is that even with these new estimates MMR rates are still way too high in many regions, even increasing in some countries, and the Millennium Development Goal 5 is not likely to be met globally. So we have potentially made more progress but the progress is hardly worth celebrating.
The authors argue, and I suspect correctly, that some of the biggest drivers of the observed MMR declines have been changes in fertility rates, female education, and incomes across the world. What share of these declines the global health community can really take credit for in this somewhat good news story is not really known, and that is too bad, because that is really what matters here.Share on Facebook