Children lost more than a third of a year’s worth of learning during the Covid-19 pandemic, according to a worldwide study that shows gaps in skills and knowledge have persisted long after schools reopened.

Bastian Betth?user, author of the report in science journal Nature Human Behaviour, warned that education authorities’ focus was “shifting away” from helping school-aged children recover lost knowledge and skills during the pandemic, highlighting a need for continued support for catch-up learning.

Academic subjects that depended most on teacher-led learning, such as mathematics, suffered the most when classes moved online, researchers said, with damaging consequences for individual career prospects, labour markets and overall inequality. The paper, which focused on 15 high- and middle-income countries and was published on Monday, added that the educational impact was more pronounced for children from disadvantaged backgrounds.