NHS Scotland has recouped less than half the costs spent treating patients from Europe and overseas in the past five years.

Around £4 million out of £9m has been reimbursed.

Papers submitted to MSPs show that health boards in Scotland spent £4 million between April 2013 and March 2017 treating international patients not from the European Economic Area (EEA), and therefore not entitled to free healthcare on the NHS. Of this, £2.75m has been recovered to date.

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The figures were outlined by NHS Scotland chief executive Paul Gray in a letter to Holyrood's Health and Sport Committee.

He added: "It should be noted that all NHS Boards have procedures in place to pursue and recover treatment costs and that a number of patients will have been waiting for their insurance company to settle or will have had repayment plans in place."

Mr Gray said it was unclear how many overseas patients had received treatment on NHS Scotland during this time as these figures were not collected centrally by the Scottish Government, but stressed that "anyone that requires NHS treatment while in Scotland will receive it, based on medical priority".

The documents also detail spending on treatment for non-UK citizens visiting from the EEA region, who are entitled to free healthcare under reciprocal arrangements covered by the European Healthcare Insurance Card (EHIC) scheme.

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The issue has been thrust into the spotlight as Brexit raised questions over how Brits' medical care would be covered on the Continent in future.

Mr Gray states that 4841 individuals from non-UK EEA countries had been treated on NHS Scotland since 2014/15, at a cost of £5m.

NHS Scotland was reimbursed £1.25m in line with arrangements drawn up by the Department of Health in 2014, which promised participating health boards and NHS trusts across the UK that they would be directly repaid 25% of the costs of treating EEA patients in exchange for reporting the data.

Without it, the UK Government cannot apply to other EEA countries to be reimbursed.

Mr Gray said: "The 25% level was seen as affordable and sufficient to motivate a higher number of Boards and Trusts to participate."

The remainder of the healthcare costs repaid to the UK Government by other EEA countries goes direct to the Treasury.

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Prior to the roll-out of EHIC in 2014, healthcare providers did not see a direct financial benefit from collecting and reporting data on EEA patients. As a result, reporting was inconsistent across the UK.

Nonetheless, six health boards in Scotland - Dumfries and Galloway, Fife, Forth Valley, Greater Glasgow and Clyde, Lanarkshire and Western Isles - still do not gather the information.

Mr Gray said: "The reasons they have given for not participating include administrative costs outweighing potential income from the scheme."

As a result, he said £10m - or £2m per year - was a "reasonable estimate" for the true cost to NHS Scotland of treating EEA visitors.

Meanwhile, the UK Government is paying around £630m a year to other EEA countries to cover the cost of healthcare they have provided to UK nationals, including visitors from Scotland.

This is largely driven by the "far larger numbers of UK nationals [who] retire to live in Southern Europe than the other way round", said Mr Gray.