There is a lack of evidence from low- and middle-income countries though.

They represent more than half of the estimated four million individuals in low and middle-income countries on treatment.

Almost all of the nation's growth in exports last year came from sales to poor and middle-income countries, which rose 13.6 percent.

The increase is related to higher economic growth projected in low- and middle-income countries.

In most poor and even middle-income countries, many girls stay home while their brothers go to primary school.

Generally, the standard of care in the public sector is high for a middle-income country.

School health systems are expanding in low- and middle-income countries.

Globally, 70 percent of all older people now live in low or middle-income countries.

For the middle-income countries, the primary issue is market access.

The language used to teach children in low- and middle-income countries has become an urgent issue.