The country fell five places into the bottom half of nations cross a range of measures including income, education, longevity and inclusivity. Only Wales saw a similarly steep fall in the figures published today.

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It has prompted questions about the "shortcomings" of devolution and whether changes are now needed in "still young" system north of the border.

The country fell five places into the bottom half of nations cross a range of measures including income, education, longevity and inclusivity. Only Wales saw a similarly steep fall in the figures published today.

Eastern European countries like Estonia, which has moved above Scotland, and the Czech Republic saw significant increases in their performance.

Professor John McLaren of the Scottish Trends website said the Scottish Parliament may have to adopt a more "radical" approach to address well-being.

“The Index highlights shortcomings in improving key Scottish objectives, like improving health and education standards, when compared to the progress made in other countries,"

MSPs at Holyrood may need to adopt a more radical approach to tackling well-being

"Next months budget provides another opportunity to start to better address issues such as poverty, social care, mental health, equality and climate change. This will be challenging given the pressure to, once again, divert most of the funding increase into boosting the NHS budget.

"At present, the willingness across the Scottish Parliament to be radical enough to seriously reorient current spending patterns seems thin on the ground but without such profound changes then improvements in key aspects of the quality of life may fail to emerge over the next twenty years of devolution.”

Many experts are increasingly looking beyond economic growth (GDP) as a measure of success and well-being is an increasingly popular way for governments to assess their performance. The Scottish Government itself is committed to introducing well being as a key aspect of future budget decision making.

The Index allows for a comparison of the relative progress of 32 OECD countries (including the four constituent countries of the UK) to be made between 2006 and 2018,

Scotland's fell down to 21st in the latest table due to a decline in its education and income performances, with the latter associated with the decline in North Sea related activity. Despite this, Scotland’s very poor life expectancy performance remains its weakest area of performance.

Wales and Northern Ireland both fell into the bottom quartile of countries, principally due to poor GDP performances.

The Scottish Trends paper adds: "The relatively poor Scottish performance, in terms of education and health, suggests that changes may be needed to the, still young, devolved political system. Such changes should involve strengthening the challenge and scrutiny roles both within and out-with the Parliament."

Liberal Democrat leader Willie Rennie said: “Scotland is a great place to live but our government has failed to get to grips with fundamental challenges facing our economy and our society.

“Rather than spend more years distracted by the prospect of an independence referendum, the Scottish Government should be focusing on tackling serial failings in health and education. Unless there is a change of approach we will continue to fall further behind our international compatriots."

Scotland has one of the biggest falls in "well-being" index among developed countries