There are important methodological issues
There are important methodological issues affecting the study of child mortality inequalities on the basis of survey data. McKinnon and colleagues relied on rigorous analytical tools to study these changes, and in some aspects—for example the graphical display of the statistical significance of changes in inequality indices—their approach was innovative. However, any such analyses cannot avoid the limitations of the underlying data. First, to achieve sufficient sample size by quintiles, the standard practice is to rely on all deaths reported in the 10 years before the survey, which means that the midpoint for each estimate refers to a date that is 5 years before the survey. Second, household assets are measured at the time of the interview, and the family\'s socioeconomic position at this time might be different from what it was at the time the child died. Third, neonatal deaths are rare events in statistical terms—even more so than all under-5 deaths—meaning that the precision of the estimates is low. Nevertheless, survey data are the best currently available for national-level estimates, so one has to live with these limitations. But one cannot help wondering whether these limitations explain why socioeconomic disparities in more precisely measured outcomes—such as child stunting or coverage of interventions such as skilled birth attendants—tend to be much more marked than those for mortality rates.
As is the case for most good pieces of research, this paper raises as many, if not more, questions than it answers. How can we improve measurement of mortality rates to avoid the methodological pitfalls described above? If inequalities in under-5 mortality are not being reduced but those in neonatal mortality are falling, might this be explained by increased inequalities in post-neonatal deaths? Will countries with reduced inequalities continue to perform equally well when neonatal mortality declines and further rad51 inhibitor becomes dependent on more sophisticated interventions such as surfactant therapy or neonatal care units? Which types of health policy, programme, intervention, and delivery channel were most strongly related to improved equity in mortality? The will be launched in mid-2014, and is already receiving wide attention. Continued monitoring of inequalities in newborn intervention coverage and mortality rates must be a key aspect of any such strategy for reaching every mother and newborn.
In 2008, the World Health Assembly endorsed the Global Noncommunicable Disease Action Plan amid growing evidence that NCDs have replaced communicable disease as the most common cause of premature mortality worldwide. Chronic kidney disease (CKD), a non-communicable disorder included in the plan, is ranked 18th among the global causes of death—it was ranked 27th in 1990, and the number of deaths from CKD has risen by 82% during that time. It is the third largest increase among the top 25 causes of death, behind HIV/AIDS (396%) and diabetes (93%). In the adult US population the estimated prevalence of CKD stage 1–4 is 11·6% (about 26 million people), a figure similar to that reported in other high-income countries, such as Norway (10·2%), Japan (12·7%), Taiwan (11·8%), China (10·7%), and South Korea (13·7%). Less information, however, is available from low-to-middle-income countries, where prevalence of mild-to-moderate CKD is variable but generally lower than 20% of the total adult population. Even more scarce are CKD data from very poor regions, such as sub-Saharan Africa. In , John Stanifer and colleagues assessed the largely sparse and anecdotal information about the epidemiology of CKD in sub-Saharan Africa in their systematic review and meta-analysis. Only 21 of the retrieved 90 articles were regarded as suitable for the analysis (being of medium-to-high quality), eventually providing data for only 13 of 47 countries in the region. Most of the 44 145 studied individuals were younger than the age at which renal function naturally declines, with a mean age ranging from 35 years to 46 years. With this background and the limitation of data missing for most countries, the overall prevalence of CKD in the region was 13·9% (95% CI 12·2–15·7), with estimates ranging from 2% in Cote d\'Ivoire to 30·2% in Zimbabwe, and approaching 20% in Ghana, Nigeria, Rwanda, and DR Congo. Between-country differences in reported data are largely a result of the unavailability of blood or dipstick urine tests to diagnose kidney disease, even though they are very simple or inexpensive. The diagnosis of CKD is therefore easily missed. Estimated CKD prevalences could also simply depend on between-country differences in CKD definition and populations screened. Therefore, firm conclusions about CKD prevalence in the region cannot be reached, but the true burden is probably high.