A health worker takes a blood sample from a woman during large-scale testing for the new coronavirus in Jakarta, Indonesia, Monday, June 8, 2020. Indonesia's capital partly reopened on Monday after two months of lockdown, as the world's fourth most populous nation gradually reopens its economy. (AP Photo/Dita Alangkara)(AP)
A health worker takes a blood sample from a woman during large-scale testing for the new coronavirus in Jakarta, Indonesia, Monday, June 8, 2020. Indonesia's capital partly reopened on Monday after two months of lockdown, as the world's fourth most populous nation gradually reopens its economy. (AP Photo/Dita Alangkara)(AP)

Coronavirus pandemic: Implications of false-negative Covid-19 tests evaluated

More emphasis should be placed on addressing the inaccuracy of diagnostic tests for COVID-19, which play a key role in containing the pandemic, say scientists, who suggest that government agencies urge manufacturers to provide details of their tests’ clinical sensitivity.
By Press Trust of India | Posted by: Alfea Jamal | Washington DC
UPDATED ON JUN 08, 2020 02:08 PM IST

More emphasis should be placed on addressing the inaccuracy of diagnostic tests for COVID-19, which play a key role in containing the pandemic, say scientists, who suggest that government agencies urge manufacturers to provide details of their tests’ clinical sensitivity.

The researchers, including those from The Geisel School of Medicine at Dartmouth in the US, said there is lack of widespread testing as a major barrier to safely reopening economies. In the analysis, published in the New england Journal of Medicine, the scientists said while progress has been made in expanding testing, there is still concern on the accuracy of the process. “Diagnostic tests, typically involving a nasopharyngeal swab, can be inaccurate in two ways,” said study lead author Steven Woloshin from The Geisel School of Medicine. A false-positive result mistakenly labels a person infected, with consequences including unnecessary quarantine and contact tracing, Woloshin explained.

According to the scientists, the sensitivity for many available tests could be substantially lower. Citing earlier studies, they said this value could be 70 per cent. “At this sensitivity level, with a pretest probability of 50 per cent, the post-test probability with a negative test would be 23 per cent -- far too high to safely assume someone is uninfected,” the scientists wrote in the journal article. “False-negative results are far more consequential because infected persons who might be asymptomatic may not be isolated and can infect others,” Woloshin said.

In their analysis, the researchers discussed factors contributing to the current limitations of diagnostic tests.

They said variability in test sensitivity, and the lack of a standard process for validating this is a cause for concern.

Citing several large studies, the researchers also said frequent false-negative results reported in several parts of the world are concerning.

From an analysis of a preprint systematic review of five studies, involving 957 patients “under suspicion of COVID-19” or with “confirmed cases”, the scientists said false negatives ranged from 2 to 29 per cent.

But they said this evidence is less concrete due to the differences among the nature of the diagnosis tests used to assess these patients.

“However, the certainty of the evidence was considered very low because of the heterogeneity of sensitivity estimates among the studies, lack of blinding to index-test results in establishing diagnoses, and failure to report key RT-PCR characteristics,” the scientists wrote in their analysis. Based on their assessment of review research about diagnosis tests, the researchers said, frequent false negatives in the commonly used diagnosis method, RT-PCR, is concerning while the evidence on this also limited.

“Diagnostic testing will help to safely open the country, but only if the tests are highly sensitive and validated against a clinically meaningful reference standard -- otherwise we cannot confidently declare people uninfected,” Woloshin said. The researchers said, drug approval agencies like the US Food and Drug Administration (FDA) should ensure that test manufacturers provide details of their tests’ clinical sensitivity, and specificity at the time of market authorisation. They said tests without such information will hav e less relevance to patient care.

“Measuring the sensitivity of tests in asymptomatic people is an urgent priority,” Woloshin said. “A negative result on even a highly sensitive test cannot rule out infection if the pretest probability -- an estimate before testing of a person’s chance of being infected -- is high, so clinicians shouldn’t trust unexpected negative results,” he added.

According to Woloshin, this estimate might depend on how common COVID-19 is where a person lives, their exposure history, and symptoms.

(This story has been published from a wire agency feed without modifications to the text. Only the headline has been changed.)

Follow more stories on Facebook and Twitter

SHARE THIS ARTICLE ON
Topics
US
app
Close
Kamala Harris at the US president inauguration ceremony in a deeply symbolic purple ensemble by designers Christopher John Rogers and Sergio Hudson. (Photo: Agencies)
Kamala Harris at the US president inauguration ceremony in a deeply symbolic purple ensemble by designers Christopher John Rogers and Sergio Hudson. (Photo: Agencies)

Style File: US President inauguration signals inclusivity

By Manish Mishra
UPDATED ON JAN 22, 2021 12:45 AM IST
It’s hard to overlook the degree of symbolism in Kamala Harris’ sartorial pick to the inauguration ceremony of President-elect Joe Biden
Close
What’s in store for Aries, Virgo, Libra, Scorpio and other zodiac signs.
What’s in store for Aries, Virgo, Libra, Scorpio and other zodiac signs.

Horoscope Today: Astrological prediction for January 22

By Dr Prem Kumar Sharma, Manisha Koushik
PUBLISHED ON JAN 22, 2021 12:10 AM IST
Daily horoscope: Are the stars lined up in your favour? Find out the astrological prediction for Aries, Leo, Virgo, Libra and other zodiac signs for January 22.
Close
U.S. Vice President Kamala Harris walks the abbreviated parade route after U.S. President Joe Biden's inauguration on January 20, 2021 in Washington, DC. Biden became the 46th president of the United States earlier today during the ceremony at the U.S. Capitol.(AFP)
U.S. Vice President Kamala Harris walks the abbreviated parade route after U.S. President Joe Biden's inauguration on January 20, 2021 in Washington, DC. Biden became the 46th president of the United States earlier today during the ceremony at the U.S. Capitol.(AFP)

Pearls, purple and American designers mark a new U.S. administration

Reuters
PUBLISHED ON JAN 22, 2021 12:05 AM IST
Kamala Harris, the first woman, the first Black person and the first Asian American to hold the office, chose Black designers for the historic moment.
Close
U.S. President Joe Biden and first lady Jill Biden stand for the national anthem sung by Patti LaBelle as they participate remotely in a virtual Presidential Inaugural Prayer Service from the State Dining Room at the White House in Washington, U.S., January 21, 2021.(Reuters)
U.S. President Joe Biden and first lady Jill Biden stand for the national anthem sung by Patti LaBelle as they participate remotely in a virtual Presidential Inaugural Prayer Service from the State Dining Room at the White House in Washington, U.S., January 21, 2021.(Reuters)

Joe Biden inauguration ceremony: Celebrities amp up their fashion game

ANI
UPDATED ON JAN 21, 2021 11:22 PM IST
The swearing-in of Joe Biden as the new President of the United States of America took place on Wednesday.
Close
Leonardo da Vinci’s 16th century “Salvator Mundi” painting of Jesus Christ(Wikipedia)
Leonardo da Vinci’s 16th century “Salvator Mundi” painting of Jesus Christ(Wikipedia)

Italian police find stolen copy of Leonardo 'Salvator Mundi'

AP
PUBLISHED ON JAN 21, 2021 10:54 PM IST
Italian police have recovered a 500-year-old copy of Leonardo da Vinci’s 16th century “Salvator Mundi” painting of Jesus Christ that was stolen from a Naples church during the pandemic without the priests even realizing it was gone.
Close
The researchers, including those from the University of Nottingham in the UK, found that the best predictor of people's compliance to the rules was how much their close circle complied with the rules(Unsplash)
The researchers, including those from the University of Nottingham in the UK, found that the best predictor of people's compliance to the rules was how much their close circle complied with the rules(Unsplash)

People more likely to follow Covid rules when friends and family do, study says

PTI, London
PUBLISHED ON JAN 21, 2021 07:23 PM IST
People are more likely to follow Covid-19 restrictions based on what their friends do, rather than their own principles, according to a study that shows how social influence affects adherence to government interventions.
Close
The studio that teaches design and restoration to a new generation of fan-makers was placed on France’s intangible heritage list last year.(AP)
The studio that teaches design and restoration to a new generation of fan-makers was placed on France’s intangible heritage list last year.(AP)

Virus pushes storied Paris fan museum to brink of folding

AP, Paris
PUBLISHED ON JAN 21, 2021 06:30 PM IST
Just like the leaves of its gilded fans, France’s storied fan-making museum could fold and vanish. The splendid Musee de l’Eventail in Paris, classed as a historical monument, is the cultural world’s latest coronavirus victim.
Close
People are more likely to follow Covid-19 restrictions based on what their friends do, rather than their own principles, according to a study that shows how social influence affects adherence to government interventions.(Unsplash)
People are more likely to follow Covid-19 restrictions based on what their friends do, rather than their own principles, according to a study that shows how social influence affects adherence to government interventions.(Unsplash)

People more likely to follow Covid rules when friends and family do, study says

PTI
PUBLISHED ON JAN 21, 2021 05:55 PM IST
People are more likely to follow Covid-19 restrictions based on what their friends do, rather than their own principles, according to a study that shows how social influence affects adherence to government interventions.
Close
Treating severe Covid-19 patients with the arthritis drug tocilizumab along with standard care is no better than standard care alone in improving clinical outcomes at 15 days, says the results of a trial.(Unsplash)
Treating severe Covid-19 patients with the arthritis drug tocilizumab along with standard care is no better than standard care alone in improving clinical outcomes at 15 days, says the results of a trial.(Unsplash)

Arthritis drug no better than standard care for severe Covid-19, says study

PTI
PUBLISHED ON JAN 21, 2021 05:31 PM IST
Treating severe Covid-19 patients with the arthritis drug tocilizumab along with standard care is no better than standard care alone in improving clinical outcomes at 15 days, says the results of a trial which was stopped early due to increased number of deaths among those receiving the drug.
Close
Representational Image(Unsplash)
Representational Image(Unsplash)

New tool helps calculate Covid transmission risk in poorly-ventilated places

PTI
PUBLISHED ON JAN 21, 2021 04:27 PM IST
The research also shows that the virus spreads further than two meters in seconds in poorly-ventilated spaces.
Close
The travel industry and travellers, both expects 2021 to be better than 2020. (Photo: Deepak Sansta / HT)
The travel industry and travellers, both expects 2021 to be better than 2020. (Photo: Deepak Sansta / HT)

Wanderlust reignited: Republic Day weekend attract tourists

By Ruchika Garg, New Delhi
UPDATED ON JAN 21, 2021 04:21 PM IST
According to a leading travelling company, there has been a 30% increase in bookings for the upcoming Republic Day weekend.
Close
Lady Gaga arrives to perform the National Anthem as President-elect Joe Biden and Vice President-elect Kamala Harris watch during the 59th Presidential Inauguration at the U.S. Capitol, in Washington, U.S., January 20, 2021.(Reuters)
Lady Gaga arrives to perform the National Anthem as President-elect Joe Biden and Vice President-elect Kamala Harris watch during the 59th Presidential Inauguration at the U.S. Capitol, in Washington, U.S., January 20, 2021.(Reuters)

Passion and fashion: Lady Gaga's powerful anthem at US Presidential inauguration

AP
UPDATED ON JAN 21, 2021 04:21 PM IST
A full-throated, supremely confident Lady Gaga belted out the national anthem at President Joe Biden's inauguration in a very Gaga way — with flamboyance, fashion and passion.
Close
Katrina Kaif does Pilates in new fitness video(Instagram/katrinakaif)
Katrina Kaif does Pilates in new fitness video(Instagram/katrinakaif)

Katrina Kaif is the latest Pilates fan, shares new video from rigorous session

By Nishtha Grover, Delhi
PUBLISHED ON JAN 21, 2021 04:15 PM IST
  • Katrina Kaif recently shared a video from her extreme Pilates session. Looking radiant in a bright red co-ord set, the actor inspired us to stop procrastinating and hit the gym.
Close
New York City has opened $25 billion worth of contracts to bids from LGBT+-owned businesses as part of a pledge to widen access to a raft of benefits already offered to other minorities, from women to Black entrepreneurs.(Yahoo)
New York City has opened $25 billion worth of contracts to bids from LGBT+-owned businesses as part of a pledge to widen access to a raft of benefits already offered to other minorities, from women to Black entrepreneurs.(Yahoo)

New York City opens billions in contracts to LGBT+ business

Reuters
UPDATED ON JAN 21, 2021 04:07 PM IST
New York City has opened $25 billion worth of contracts to bids from LGBT+-owned businesses as part of a pledge to widen access to a raft of benefits already offered to other minorities, from women to Black entrepreneurs.
Close
Dubai has suspended non-essential surgery for a month and live entertainment in hotels and restaurants until further notice as coronavirus infections surge in the Middle East trade hub.(Unsplash)
Dubai has suspended non-essential surgery for a month and live entertainment in hotels and restaurants until further notice as coronavirus infections surge in the Middle East trade hub.(Unsplash)

Dubai cancels non-essential surgery, live entertainment as Covid-19 cases surge

Reuters
PUBLISHED ON JAN 21, 2021 03:50 PM IST
Dubai has suspended non-essential surgery for a month and live entertainment in hotels and restaurants until further notice as coronavirus infections surge in the Middle East trade hub.
Close
SHARE
Story Saved
OPEN APP