a1 Department of Nutrition for Health and Development, World Health Organization, 20 Avenue Appia, CH-1211, Geneva 27, Switzerland
a2 Division of Nutrition and Physical Activity, Centers for Disease Control and Prevention (CDC), USA
a3 Institute of Food Science and Nutrition, Swiss Federal Institute of Technology, Zurich, Switzerland
a4 Escuela de Estadistica, Universidad Nacional de Rosario, Argentina
Objective To provide current global and regional estimates of anaemia prevalence and number of persons affected in the total population and by population subgroup.
Setting and design We used anaemia prevalence data from the WHO Vitamin and Mineral Nutrition Information System for 1993–2005 to generate anaemia prevalence estimates for countries with data representative at the national level or at the first administrative level that is below the national level. For countries without eligible data, we employed regression-based estimates, which used the UN Human Development Index (HDI) and other health indicators. We combined country estimates, weighted by their population, to estimate anaemia prevalence at the global level, by UN Regions and by category of human development.
Results Survey data covered 48·8 % of the global population, 76·1 % of preschool-aged children, 69·0 % of pregnant women and 73·5 % of non-pregnant women. The estimated global anaemia prevalence is 24·8 % (95 % CI 22·9, 26·7 %), affecting 1·62 billion people (95 % CI 1·50, 1·74 billion). Estimated anaemia prevalence is 47·4 % (95 % CI 45·7, 49·1 %) in preschool-aged children, 41·8 % (95 % CI 39·9, 43·8 %) in pregnant women and 30·2 % (95 % CI 28·7, 31·6 %) in non-pregnant women. In numbers, 293 million (95 % CI 282, 303 million) preschool-aged children, 56 million (95 % CI 54, 59 million) pregnant women and 468 million (95 % CI 446, 491 million) non-pregnant women are affected.
Conclusion Anaemia affects one-quarter of the world’s population and is concentrated in preschool-aged children and women, making it a global public health problem. Data on relative contributions of causal factors are lacking, however, which makes it difficult to effectively address the problem.
(Received May 28 2007)
(Accepted March 06 2008)