A follow-up study of children who received Reading Recovery has found that the effects can still be seen three years later.
Reading Recovery is aimed at six-year-olds in the bottom 5 per cent of readers. Pupils get a 30-minute daily lesson from a trained teacher.
The method is at the heart of the Every Child a Reader programme, under which Reading Recovery teachers also train staff and monitor less intensive literacy interventions throughout the school.
The study, carried out by Jane Hurry and Andrew Holliman of London University's Institute of Education, found that at the end of Year 4, children who had received Reading Recovery were assessed, on average, as working at level 3b - on track for the expected level 4 at the end of Year 6.
By contrast, children who were at a similar standard in Year 1 but had not received Reading Recovery lessons were, on average, at level 2a.
The study, of 73 children who had received Reading Recovery and 48 who had not, also found that the Reading Recovery children were significantly less likely to be identified as having special educational needs.
Jeremy Lunnon, head of St Margaret's CofE Primary in Plumstead, south-east London, said: "We first used it more than 12 years ago, but funding dried up about five years ago. Then, when funding came from Every Child a Reader, we seized the opportunity to get back into it again. There is a clear impact on progress.
"To maintain it takes quite a lot of work and we wouldn't do it if it was not adding to children's progress. It works in different ways - some children we do revisit, while others make very rapid progress following the programme.
"Just before Christmas, one of our former pupils came to see her younger brother in a nativity play. She was someone who was pulled up (went through the Reader Recovery programme) and then went from strength to strength and is at university now."
But Reading Recovery has not been free of controversy. A report by the Commons science and technology committee said that evidence supporting its use was of a lower quality than it would expect. It said the programme should not have been rolled out without a randomised controlled trial and called for promising alternatives to be identified and trials put in place.
Criticism of the scheme has centered around its mixed methods. The committee said that although there was more phonics in the modern version, this did not constitute the systematic phonics recommended by government.
By the summer of 2011, 1,800 teachers are expected to be trained in the reading scheme, and 30,000 six-year-olds to have been helped.
The Government funds half the cost - about #163;10,000 - of employing a Reading Recovery teacher. Schools are expected to find the rest of the money.