Washington, Nov 10 (IANS): The child mortality gap has narrowed between the poorest and wealthiest households in more than 50 developing countries, says a new study from Stanford University's School of Medicine.

The findings provide important information for making decisions about prioritising global health investments to effectively promote equity.

"In many countries, national wealth has increased hand-in-hand with increasing health inequality. That has been a signature of our time," said Eran Bendavid, assistant professor of medicine.

To compare wealth status and under-five child mortality within a country, Bendavid used data from the demographic and health surveys for 1.2 million women living in 929,224 households in 54 developing countries.

He developed a three-tier wealth index using the household assets.

The three wealth categories were - poorest, middle and wealthiest.

The under-five mortality rates among the poorest groups had decreased the most rapidly, found the study.

"The average decline was 4.36 deaths each year per 1,000 live births among the poorest, 3.36 among the middle and 2.06 among the wealthiest," Bendavid said.

As the poorest group's mortality rate is decreasing more quickly that the other groups, the gap in child-mortality rates is closing.

The difference in mortality rates was linked with governance scores.

Better governance scores were related to greater convergence in mortality rates among the three wealth groups.

"The study is an important contribution to knowledge about child health improvements in the developing world," concluded Davidson Gwatkin, senior fellow at Results for Development Institute in Washington, DC.

The study appeared in the journal Pediatrics.