In the last two decades, the world has spent more than $196 billion trying to save people from death and disease in poor countries.
Millions of people are now protected against diseases like yellow fever, sleeping under anti-malaria bed nets and taking AIDS drugs.
But there isn't much proof that pricey programs led by the United Nations and its partners are responsible, according to two studies published Friday in the medical journal, Lancet.
Trying to show health campaigns actually saved lives is "a very difficult scientific dilemma," said Tim Evans, a senior World Health Organization official who worked on one of the papers.
In one paper, WHO researchers examined the impact of various global health initiatives during the last 20 years.
Some programs hurt care
They found some benefits, like increased diagnosis of tuberculosis cases and higher vaccination rates. But they also concluded some U.N. programs hurt health care in Africa by disrupting basic services and leading some countries to slash their health spending.
In another paper, Chris Murray of the University of Washington and colleagues tracked how much has been spent in public health in the last two decades — the figure jumped from $5.6 billion in 1990 to $21.8 billion in 2007 — and where it’s gone. Much of that money is from taxpayers in the West. The U.S. government was the biggest donor, contributing more than $10 billion in 2007.
They found countries don't get more donations even if they're in worse shape. Ethiopia and Uganda both receive more money than Nigeria, Pakistan or Bangladesh, all of whom have bigger health crises.
Some experts were surprised how long it took simply to consider if the world's health investment paid off.
Richard Horton, the Lancet's editor, labeled it "scandalous" and "reckless" health officials haven't carefully measured how they used the world's money.
Experts said that in some cases, the U.N. was propping up dysfunctional health systems. "If you've got rotten governments, no amount of development aid is going to fix that," said Elizabeth Pisani, an AIDS expert who once worked for the U.N., citing Zimbabwe as a prime example.
Don't miss these Health stories
More women opting for preventive mastectomy - but should they be?
Rates of women who are opting for preventive mastectomies, such as Angeline Jolie, have increased by an estimated 50 percent in recent years, experts say. But many doctors are puzzled because the operation doesn't carry a 100 percent guarantee, it's major surgery -- and women have other options, from a once-a-day pill to careful monitoring.
- Larry Page's damaged vocal cords: Treatment comes with trade-offs
- Report questioning salt guidelines riles heart experts
- CDC: 2012 was deadliest year for West Nile in US
- What stresses moms most? Themselves, survey says
- More women opting for preventive mastectomy - but should they be?
Murray and colleagues also found AIDS gets at least 23 cents of every health dollar going to poor countries. Globally, AIDS causes fewer than 4 percent of deaths.
"Funds in global health tend to go to whichever lobby group shouts the loudest, with AIDS being a case in point," said Philip Stevens of International Policy Network, a London think tank.
In WHO's study, researchers admitted whether health campaigns address countries' most pressing needs "is not known."
When Cambodia asked for help from 2003-2005, it said less than 10 percent of aid was needed for AIDS. But of the donations Cambodia got, more than 40 percent went to diseases including AIDS.
WHO acknowledged change was necessary, but insisted it needed even more money, warning fewer donations would jeopardize children's' lives.
U.N. agencies, universities and others working on public health routinely take from 2 to 50 percent of a donation for "administrative purposes" before it goes to needy countries.
Others said there is little incentive for health officials to commission an independent evaluation to find out what their programs have achieved.
"The public health community has convinced the public the only way to improve poor health in developing countries is by throwing a ton of money at it," Stevens said. "It is perhaps not coincidental that thousands of highly paid jobs and careers are also dependent on it."
© 2013 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.