We would like to also

We would like to also clarify that we do not underestimate the CIs in our study through the assumption that GDP was observed independently for every child in the survey. The multilevel design and clustering of standard errors at the survey level accounts for the fact that GDP is not observed independently for each child in the survey. The larger CIs in our other paper on sub-Saharan Africa seem to refer to the macro-level regressions and not the micro-level regressions, which are also reported in that paper.
In their letter on falsified medicines in Africa (September issue), Paul Newton and colleagues lament obstacles to improving the global supply of drugs, especially in unregulated informal markets in Africa. We share their concerns, but the authors do overlook important efforts to curb the flood of fake and substandard malaria medicines. The US President\'s Malaria Initiative, for one, is teaming up with local police, customs agents, national medicines regulatory authorities, and drug sellers to help reduce the availability of counterfeit drugs in informal private sector outlets and marketplaces. The President\'s Malaria Initiative is working programmatically with the US Agency for International Development\'s Office of Inspector General (USAID OIG) to address and mitigate availability of counterfeit drugs in the market place. For example, in Benin, in a mostly unregulated market in which shop owners and street vendors sell drugs, including antimalarials, the Initiative is partnering with the USAID OIG, local law enforcement, and Ministry of Health officials to launch an anticounterfeit outreach programme by educating and incentivising shopkeepers to report suspected counterfeit medicine networks, while informing guanylyl cyclase on the dangers of substandard drugs and how to recognise them. Benin is the first of several sub-Saharan African countries where this initiative will be implemented. And, the USAID OIG is actively investigating crimes, working with local law enforcement agencies in several countries, leading to arrests and prosecutions. In all 19 focus countries in Africa, the President\'s Malaria Initiative is partnering with national medicines regulatory authorities to help strengthen local capacities regarding drug quality as part of the US Government\'s overall technical assistance towards strengthening health systems. The Initiative is helping countries improve surveillance capacity to better monitor drug quality through randomly testing drugs commonly found in both the private and public sectors, including mini-laboratory sentinel sites, and pilot activities in collaboration with the US Food and Drug Administration and their CD-3 device. Although we agree population medicines regulatory authorities need to be strengthened, we are seeing important progress. Recently, two national drug reference laboratories in sub-Saharan Africa received ISO-17025 accreditation—an internationally recognised standard regarding laboratory competency. These long-term gains represent sustainable health systems capacity building, enabling partner country medicines regulatory authorities to perform much needed quality testing. The President\'s Malaria Initiative is providing substantial support to countries to improve regulation and enforcement capacity of both the public and private sectors, and we are expanding efforts with partner countries to strengthen all areas of their pharmaceutical supply chain, including forecasting, storage, transportation, and inventory management. Finally, as a major procurer of artemisinin-based antimalarials, the Initiative employs a stringent quality assurance and quality control strategy, ensuring that only good quality drugs are used in support of US Government malaria programmes not only in sub-Saharan Africa, but also the greater Mekong subregion. Although there are various estimates of the burden of fake drugs, WHO believes that fake medicines are now a US$75 billion per year industry. We agree with Newton and colleagues that more must be done to assure quality of medicines, and second their call for an international public health convention on the topic.