India has avoided the deaths of about one million children under the age of five since 2005, largely due to a decrease in cases of preventable diseases such as pneumonia, diarrhea, tetanus and measles, a study found.

The study took a novel approach carrying out "verbal autopsies" as census staff knocked on more than 1.3 million doors to speak to households about infant mortality, in a country where many deaths occur at home and without medical attention.

"It's huge progress," said Prabhat Jha, lead investigator of the survey. "The most important thing that India has done is actually count the deaths."

Mortality rates from vaccine-preventable diseases such as tetanus and measles fell by about 90%

Jha told the Thomson Reuters Foundation that the approach, which included using local languages and listening to parents tell unvarnished stories of their children's deaths, was simple and cheap and could be replicated elsewhere.

"(India) has got a simple way of counting the dead and describing causes that many countries could adopt at low cost; this isn't hard stuff, it just needs a bit of money and some political commitment," he said.

The research, published online September 19 in The Lancet, is part of a wider Million Death Study taking place across India and is one of the largest studies of premature deaths in the world.

The study found that mortality rates from vaccine-preventable diseases such as tetanus and measles fell by about 90% since 2005 while neonatal infection and birth trauma fell by more than 66%.

For children aged one to 59 months, mortality rates from pneumonia and diarrhea also fell by more than 60%, according to the research.

Improved female literacy rates, schemes paying women to deliver babies in hospitals and an increase in spending on public health by the Indian government have all contributed to the falling death rates.

Worldwide, more than six million children die before their fifth birthday each year, according to the United Nations, with children born into poverty almost twice as likely to die before the age of five as those from wealthier families

"It is clear that there is good progress in some states in India – but this is not shared across all communities," said Vishal Chowla of Save the Children in India.

"Access to healthcare remains unequal, and very low public spending means that the poor are often left to fend for themselves."

Worldwide, more than six million children die before their fifth birthday each year, according to the United Nations, with children born into poverty almost twice as likely to die before the age of five as those from wealthier families.

The UN's Sustainable Development Goals seek to end the preventable deaths of newborns and children under five, with countries aiming to reduce infant mortality to at least as low as 25 per 1,000 live births by 2030.

In India, more needs to be done to reduce malaria deaths and improve maternal health to prevent low birth weights, said Jha.

"The key message is even modest, imperfect public health action when you start at low levels of coverage can have a huge impact."