<P> The use of health information lies at the root of evidence - based policy and evidence - based management in health care . Increasingly, information and communication technologies are being utilised to improve health systems in developing countries through: the standardisation of health information; computer - aided diagnosis and treatment monitoring; informing population groups on health and treatment . </P> <P> The management of any health system is typically directed through a set of policies and plans adopted by government, private sector business and other groups in areas such as personal healthcare delivery and financing, pharmaceuticals, health human resources, and public health . </P> <P> Public health is concerned with threats to the overall health of a community based on population health analysis . The population in question can be as small as a handful of people, or as large as all the inhabitants of several continents (for instance, in the case of a pandemic). Public health is typically divided into epidemiology, biostatistics and health services . Environmental, social, behavioral, and occupational health are also important subfields . </P> <P> Today, most governments recognize the importance of public health programs in reducing the incidence of disease, disability, the effects of ageing and health inequities, although public health generally receives significantly less government funding compared with medicine . For example, most countries have a vaccination policy, supporting public health programs in providing vaccinations to promote health . Vaccinations are voluntary in some countries and mandatory in some countries . Some governments pay all or part of the costs for vaccines in a national vaccination schedule . </P>

According to the world health organization a health system is described as all except