The World Health Organization (WHO), established in 1948, is the directing and coordinating authority for health within the United Nations system.

WHO provides its 193 Member States and other agencies working in public health with information on the performance and funding of health systems and global health programmes and advises on best practice for health care. The Organization also sets standards for a range of health-related activities and information systems and maintains classification systems for diseases and injuries.

One of the Organization's pivotal roles is to monitor global health. One of the core needs of a strong health system is to know what is making people ill, why they die or how they become injured. This information assists countries to make sound and ethical health planning decisions that make the best use of resources.
Every year WHO analyses data collected from its Member States and produces a set of estimates based on health indicators such as the numbers of people dying from tuberculosis or from complications of childbirth; or the prevalence of HIV or malaria.
This information is published in the World Health Statistics, WHO's annual report card on global health, which also contains a special section that tracks progress on the health-related Millennium Development Goals. 
However, the data have some limitations as many countries do not have reliable health information systems that produce an accurate cause of death. Where the data is patchy or non-existent, WHO has developed methods of estimating the burden of disease by, for example, examining the experience of countries that have a similar profile.  WHO works to assist countries to develop better health information systems.
As well as the World Health Statistics, WHO produces updates on global risks to health and the burden of disease study.  It also provides access to data and analyses for monitoring the health situation through its Global Health Observatory (GHO) portal  (www.who.int/gho/). The GHO presents data from all WHO programmes and provides links to supporting information.
Data and statistics at WHO (www.who.int/research)

Online databases include:

1. The Global Health Observatory portal, which  gives access to health data tables for WHO Member States; statistical reports containing major analyses such as the World Health Statistics 2010; Global Burden of Disease 2004 Update; Global Health Risks update; and the Women and Health report.
2. The WHO GLOBAL InfoBase has information on chronic diseases and their risk factors for all WHO Member States. 
3. WHO’s Communicable Disease Global Atlas gives access to statistics for infectious diseases at country, regional, and global levels.
4. Regional statistics.

At www.who.int/research/there are links to statistics on:
Burden of Disease; causes of death; life expectancy; mortality; risk factors (alcohol, nutrition, overweight and obesity, and tobacco); diseases ( diabetes, HIV/AIDS, tuberculosis); coverage of services (immunization, maternal and neonatal care); health systems (national health accounts, health workforce).