The ruling relates to a 2014 case which saw a 71-year-old patient spend 421 days in a Basel hospital with serious complications after knee surgery.

Total medical costs were around 2.4 million Swiss francs (€2.1 million) with Swiss health insurer Vivao Sympany required to pay 45 percent of those costs, or 1.08 million francs, and the hospital to pay the remainder.

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But the Basel-based insurer said it would only pay 300,000 Swiss francs.

The Basel hospital where the man had been treated then took the matter to a cantonal insurance tribunal which found in the hospital's favour.

Vivao Sympany appealed, arguing that the Federal Supreme Court had previously placed an upper limit on the liability of health insurance providers.

It also argued that according to calculations using the so-called quality-adjusted life year (QALY) method, which assesses whether health interventions are good value for money, it should only pay 296,000 francs.

However, Switzerland’s highest court ruled against the insurer.

The court said it had never set an upper limit on liability and stressed in particular that QALY calculations had never been deemed applicable.

In its ruling, the court also said there was no evidence that the treatment in the current case had been more expensive than necessary, and there was therefore no reason why the insurer should not pay.

The Federal Supreme Court said that under current health insurance laws, unlimited liability was guaranteed as long as hospital treatments were effective, targeted and not economically wasteful.

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