Poor women in Cambodia are more likely to use long-term reversible forms of birth control, like IUDs or implants, if they receive outside assistance, a new study has found.

Published on August 11 in the journal Global Health: Science and Practice, the study looks at the results of a voucher program launched in six provinces in 2010 by the Ministry of Health and a handful of partners with the support of the German Development Bank. The program offers information and financial support to women who would like to use long-term reversible contraception (LARC).

About 13 per cent of married women in Cambodia who do not want to get pregnant are not using birth control, according to the UN Population Fund, and while modern contraception use in Cambodia more than doubled between 2000 and 2010, according to the study, this wasn’t the case for LARCs.

“For a woman who has reached her desired family size and no longer wants to have any more children, a longer-acting method may be preferable,” said Ashish Bajracharya, the study’s lead author.

However, the initial costs of LARCs, widely considered the most effective form of birth control, tend to be higher than for other contraception, making it more difficult for poor women to access them.

But in areas with a voucher program, LARC use increased among married women 18-45 from 1.4 per cent in 2011 to 6.7 per cent in 2013, the study found. Meanwhile, LARC use only reached 3.5 per cent in districts without assistance.

The results were even starker among the poorest quintile of participants, for whom LARC use increased from 1.1 per cent to 8.8 per cent in the regions with the program, the study found.