Nurses now undertake one consultation in three in primary care in Scotland, according to the 2009 National Primary Care Workforce Survey.
The introduction of the QOF with the 2004 contract also pushed up the overall workload of practice nurses.
But although in the six years to 2003 practice nurse numbers in Scotland shot up by one third, in the next five years and four months, they rose by only 6%.
Scottish practices and health boards now employ 2,140 practice nurses, the survey data show.
RCN Scotland director Theresa Fyffe said the new GP contract brought a need for a ‘steep increase in the number of practice nurses needed'.
Practice nurses now ‘lead on delivering an increasing range of services to patients to support the achievements of GP targets through the QOF'.
‘In return for the crucial role that practice nurses now have, all GPs should ensure that they meet best employment practice,' she added.
‘Many should improve the terms and conditions for their practice nurses, including releasing them to undertake education, development and training on an ongoing basis.'