A value-for-money review of the Supply Teacher Scheme was published in July 2006. The review found that only approx. 60% of supply teachers' time was used to cover sick leave absences. This reflects the unpredictable nature of sick leave absences.
While there are benefits for schools in having these teachers, it is considered more cost effective to use the normal substitution arrangements that apply to all other schools to cover sick leave absences, instead of having a cohort of full-time teachers ''on call'' all the time in these schools to cover sick leave absences that may or may not arise.