Sir

Your Editorial “Millennium development holes” (Nature 446, 347; doi:10.1038/446347a 2007) states correctly that better data are needed to track progress towards the Millennium Development Goals. In 2002, the United Nations secretary-general mandated UN agencies and other international organizations to provide the best available data to monitor progress toward the agreed goals. It became immediately evident that, as you state, many countries lacked the capacity to produce and report the necessary data.

Now, all but 17 of the countries involved have trend data for at least half the indicators. The international agencies to which you refer carefully review available national data sources used in compiling the indicators, and formulate methodologies when estimates are needed to assess trends in the various regions. These methodologies are then reviewed by international and national experts.

Data gaps have been clearly identified, and efforts to assist countries in the production and use of the necessary data have been scaled up. Statisticians from UN member countries have also reviewed the quality and availability of data to monitor the goals and have provided recommendations. At the 2006 and 2007 meetings of the UN Statistical Commission, a forum for the heads of national statistical systems, more than 130 countries reported on their progress in implementing these recommendations. Although noting that deficiencies still exist, the commission agreed that real progress has been made, and called for improved funding and political commitment to support the development of statistics. We believe the national and global statistical systems have benefited immensely from these efforts.

The global statistical system has made a huge effort to improve data quality and availability, from helping to conduct censuses and surveys in difficult areas to improving vital registration systems. This has produced visible results.

In addition, rather than using lack of data as an excuse for inaction, many countries have increased the use of existing data to prepare and implement goal-based strategies and to conduct rigorous research and assessment of their programmes.