The contentious scheme, due to become law later this year, will allocate a state representative to look after the wellbeing of every child under 18, with health visitors playing the role for children under five.
NHS Lothian is unlikely to have enough staff until at least 2018/19 due to a 19 per cent vacancy rate, which rises to 44 per cent in Midlothian, according to recent board papers.
Ministers have pledged to fund an additional 500 posts across Scotland, including 61 jobs in Lothian, but the health board is struggling to recruit trained staff into the posts.
The ageing workforce is posing a major risk as more than half of health visitors are over 50 and many are still entitled to an NHS “special status” where they can retire at 55, NHS Lothian’s board was told.
Last night, nursing leaders expressed “significant concerns” about capacity and urged the Scottish Government to step up its efforts to plug the gaps.
NHS Lothian officials have said they need a further £1.3 million to train 53 additional health visitors, on top of the extra posts.
Chief executive Tim Davison told a board meeting last month: “If we simply can’t get enough health visitors then we may have to look at how the service might look like in future, where people from other places might assist with child health.”
The health board must redouble its efforts to fill the vacancies rather than asking the current workforce to take on more responsibility without the resources to do so safely, said Norman Provan, Royal College of Nursing Scotland associate director.
He said: “We have significant concerns about current health visitor capacity in NHS Lothian.
“Health visitors are already under serious pressure, with NHS Lothian experiencing great difficulties recruiting enough now, let alone the additional health visitors they will need to implement the Named Person role and the recently introduced new health visitor pathway.
“While we welcome the fact that the Scottish Government is providing funding for 500 more health visitors, these additional posts are being phased in and won’t all be in place when the Named Person comes into force in August 2016.”
Campaigners against the divisive scheme said last night that it was no surprise that health visitors and health boards were struggling to cope with the “bureaucratic” responsibilities of the Named Person Act.
Simon Calvert, spokesman for the No To Named Person campaign group, said: “NHS Lothian say it will be impossible to meet the massive demands of the new scheme for two or three years at the earliest without pulling health visitors from other areas which, presumably, will be just as overstretched.
“No-one doubts the good intentions of the government, or of health visitors, but the Named Person scheme is a bureaucratic, data-harvesting nightmare which will go badly wrong.”
The Scottish Government has invested £41.6m over the four years to 2018 to provide 500 extra health visitors, to ensure staffing levels are adequate for the visits and developmental reviews, a Scottish Government spokesperson said.
The spokesperson added: “Health visitors are valued members of the nursing workforce and we remain committed to their vital contribution to improving the health and wellbeing of children, young people and families.
“The role of the Named Person is to provide a single point of contact for parents and children who can help and support them in liaising with other services.”
NHS Lothian said it has begun an intensive training process and a quicker recruitment campaign to boost numbers.