Most women in rural Zambia deliver their babies at home without skilled care because of the long distances involved in reaching emergency obstetric care, so it is crucial to address the geographic and quality barriers to health care use. These are the key findings from a study by Sabine Gabrysch from Ruprecht-Karls-Universität, Heidelberg, Germany and colleagues at the London School of Hygiene & Tropical Medicine published in this week's PLoS Medicine.

In sub-Saharan Africa, a woman's lifetime risk of dying during or following pregnancy is as high as 1 in 31 (compared to 1 in 4,300 in the developed world). Most maternal and newborn deaths in low-income countries could be prevented if all women delivered their babies in settings where skilled birth attendants (such as midwives) were available to provide emergency obstetric care to both mothers and babies if complications arise. Yet every year, roughly 50 million women worldwide give birth at home without a skilled attendant. Although poor geographic access to quality health care is likely to be a key issue for women, it has not received much attention so far.

The authors used a geographic information system and linked national household data with national health facility data to calculate straight-line distances between women's villages and health facilities. They found that only a third of births in rural Zambia occurred at a health facility, and half of all mothers lived more than 25 km from a health facility that provided basic emergency obstetric care. As distance to the closest delivery facility doubled, the odds of a woman giving birth in a health facility decreased by 29%. The level of care at the facility also had a strong influence: If the closest facility provided basic emergency obstetric care as opposed to substandard services, the odds of facility delivery were 1.5 times higher and if it provided comprehensive emergency obstetric care, they were 2.5 times higher.

The authors say: "This study clearly shows that it is important to consider the health service environment when studying use of delivery services, as both distance to services and their quality are important determinants. Ignoring these influential factors can lead to an incomplete picture and invalid conclusions." They add: "Our innovative approach of linking large-scale datasets using geographic coordinates could be applied beneficially also in other settings and fields."