The Conservatives have clashed with the Scottish Government over cancelled hospital appointments.
Official figures showed that 4.2% of meetings were cancelled by hospitals across Scotland in the three months up to June.
Tory health spokesman Jackson Carlaw pointed out that First Minister Alex Salmond vowed to improve performance substantially two years ago but he claimed it was clear there had been little change since the introduction of a £44million Patient Management System.
The figures revealed huge disparity in the rates of cancellations by health boards, with NHS Western Isles calling off 13.6% of appointments and NHS Forth Valley cancelling only 2.2%.
NHS Shetland cancelled 9% of appointments, Highland 5.5%, Orkney 2.3%, Western Isles 13.6% and Grampian 5%.
Mr Carlaw said: “The SNP should focus on dealing with these kinds of problems instead of circulating lurid scare stories about the future of the NHS in the event of a No vote.”
But a government spokesman said there was “absolutely no link” between the implementation of the patient management system and rearranged appointments.
“Since 2008, the cancellation rate for appointments has actually fallen, and we are committed to ensuring this continues,” he said.
But a spokeswoman for NHS Western Isles said appointment cancellations were of concern.
“We will be assessing these figures in more detail as a matter of priority to see what additional measures we can take to reduce cancellation rates and the resulting inconvenience to patients,” she added.
“It is, for example, sometimes necessary to cancel planned appointments when a clinician is required to deal with an emergency admission, or for reasons of sick leave.”
A spokeswoman for NHS Shetland said the figures in June related to adverse weather conditions and cancelled flights for visiting consultants, which led to cancelled appointments and clinics for patients.
“In the summer months we can suffer significant travel disruptions due to fog following periods of warmer weather which has a detrimental impact on service delivery,” she added.