Improvements in GCSE maths performance have reversed by at least three years due to the pandemic, new Ofqual analysis of 2021 National Reference Test results has revealed.

Results from the NRT showed that maths performance slipped compared to 2020, and was now closer to levels seen in 2017 when the tests launched - but there was a “surprising” lack of impact in English.

This was the first year that results could demonstrate the impact of the pandemic, as in 2020 the NRT was taken before school closures in March.

“This is not surprising, given the disruption to students’ education caused by the pandemic,” the regulator said.

But in English, results revealed no statistically significant change from previous years.

Ofqual said this was “a little surprising, given the disruption to education caused by the pandemic, and in light of the changes seen in maths”.

It added: “It may be that while the disruption meant that students had less practice in maths, they will have continued to use and respond to written and spoken English, in school in English as well as in other subjects, and outside school.

“These results suggest that the disruption caused by the pandemic might have had less impact on attainment in English than in maths.”

The results showed that in both subjects, performance at grade 4 was slightly weaker than it had been in the 2017 NRT, while at grade 7 and above, performance had improved.

“The slight increase this year in the proportion at grade 7 and above and the slight decrease at grade 4 and above indicates a widening of the underlying ability distribution relative to previous years,” Ofqual said.

The NRT, administered by the National Foundation for Educational Research, is a test to provide evidence in performance changes in GCSE English and maths.

It has run since 2017, the first year of the revised 9-1 GCSEs, and is sat by a representative sample of Year 11 pupils.

This year, owing to disruptions caused by the pandemic, the participation rate of 80 per cent of selected students was lower than for previous years.

In total, 216 schools took part in the sample compared with 331 in 2020.

Because of the pandemic, the testing window was also postponed from February or early March to between 19 April and 21 May 2021.

“Initially, 348 schools were recruited to take part in the 2021 NRT, which exceeded the usual target of 330 schools,” Ofqual said.

“However, the postponement of the test until the summer term resulted in many schools requesting to withdraw from the NRT.

In total, more than a third of the originally recruited sample withdrew between the communication of the new testing dates and the end of the testing period.”