Freedom of information requests from the Scottish Conservatives show 475 successful claims were settled by the NHS over the four-year period, totalling £163.1 million.

The true cost, however, is likely to be higher, with NHS Greater Glasgow and Clyde – the country’s biggest health board – not providing data to the party, while NHS Borders and NHS Grampian did not give figures for last year due to claims not yet being processed.

Between 2018 and 2021, the figures show, annual payouts rose from £24.5 million to just shy of £55 million.

NHS Lothian spent almost £43 million on compensation, the highest of any health board during that time.

While some boards presented a breakdown of classifications which led to claims – such as medical negligence – NHS Lanarkshire was the only one to provide further details.

According to the board, reasons for payouts included a woman’s ovary being removed without consent, a man’s testicle being removed without consent, a patient having their eye glued shut, and a “failure to properly examine baby resulting in imperforate anus going unnoticed and resulting in death”.

Responding to the figures, Scottish Tory health spokesman Dr Sandesh Gulhane said: “My heart goes out to the patients and families who have suffered as a result of failings in Scotland’s NHS.

“But the buck for this stops with a succession of SNP health secretaries – including Humza Yousaf. These figures are a damning indictment of the SNP’s dire workforce planning, which has left our health service woefully under-resourced.

“Dedicated staff are dangerously overstretched and, tragically but inevitably, this is leading to more mistakes and a growing number of compensation claims.

“At a time when budgets are so tight, the NHS can ill-afford to be spending vast sums on compensation. It goes without saying that this money could be far better spent on frontline patient care.”

Paul Cannon, the secretary of the NHS Lanarkshire board, said: “NHS Lanarkshire makes payments where the standard of care has fallen below that which would be expected, which is not necessarily an error.

“Offers to settle claims are often made before cases are tested in court, where it appears that we may be at fault, or where we accept limited liability.

“Offers are also made on an economic basis if the cost of defending the claim is grossly outweighed by the cost of settling the claim.”

A Scottish Government spokesperson said: “We sympathise with any patient whose treatment has failed to reach the standards we all expect from our health system.

“Scotland has one of the most transparent healthcare systems in the world and is also a leader in patient safety. Our NHS learns constantly from care experiences that go well and those where standards falls short.

“Particularly in rare cases of clinical negligence, health boards and care professionals must learn from these situations and make improvements. These cases can take a number of years to settle so there will be fluctuations in compensation payments from year to year.”