Concerns were also expressed about the willingness of schools to provide education with many only willing to do so when they had qualified for the Top 4 tournament.
Sandford's recommends dropping the testing and focusing on education programmes as there was no evidence to suggest testing at the Top 4 competition created a deterrent to using performance enhancing drugs.
The report said the programme was viewed as being too focused on first XV rugby and that while the initial reasons for focusing on this area was well founded it was felt other sports also had a high risk factors and anti-doping education would be beneficial for those sports too.
There are currently about 300 high school first XV teams in New Zealand with the the anti-doping programme reaching 622 students from 25 schools last year, leaving a large number of students involved not receiving education the report stated.
"There is data to suggest high amounts of supplement use in high school rugby in New Zealand and it would be naive to believe there...is not the use of prohibited substances," - however there have been no positive tests during the three years the programme has run.
Sandford also found "the main view was that testing in school sport was an uncomfortable fit and tit would be better moved into the elite group sport space outside of school sport...(and) there was no support to extend testing to other school sports."
Among the nine recommendations the review suggests testing of the 1st Fifteen Top 4 competition cease but education should continue and be widened to sports other than rugby.
It suggests School Sport New Zealand put rules in place to make it a condition of entry to events that schools and students have undertaken DFSNZ education programmes.
DFSNZ chief executive chief executive Nick Paterson welcomed the review's recommendations and said while clean sport education was their original goal, attention became focused on the small number of limited tests that DFSNZ conducted (eight tests per year) within the Schools 1st XV tournament.
This testing programme will continue, but within the high-performance environment such as sport-specific academies where support staff already have long experience of drug testing," he said.
"We will continue to build our education programme on strong collaboration and partnerships with national sports organisations, players associations and school sports organisations."