How Are
You Feeling? Surveys Aim to Detect Covid-19 Hot Spots Early
Scientists have persuaded Britons and Israelis to fill out
questionnaires about their health, to get ahead of the coronavirus by getting
resources to the right place. The U.S. is next.
More
than two million people in Britain and 150,000 Israelis have already completed
simple questionnaires, and many are updating their answers daily. Analysts of
the data — including symptoms of Covid-19 and test results, as well as risk
factors and demographics — say they have been able to identify incipient
outbreaks days ahead of the authorities.
Three
groups in the United States — led by Massachusetts General Hospital, the
Massachusetts Institute of Technology and Weill Cornell Medicine in New York —
are now vying to attract enough survey participants nationwide to detect
impending hot spots.
In Israel, where artificial-intelligence experts at the
Weizmann Institute of Science have played a leading role in the effort,
computer models that were fed the results of questionnaires accurately
predicted surges in cases in cities like Bnei Brak, Jerusalem and Beersheva
five days in advance, researchers said.
The
questionnaires, which are web or app based, ask people about their medical
histories and risk factors, and then about symptoms. In Israel, a bot prompts
users to choose from a menu including coughing, sore throat, shortness of
breath, fatigue and a loss of taste or smell, and then asks for a temperature
reading from the last 24 hours.
“Imagine,
if the Ministry of Health had acted on that information, maybe they could have
saved more spreading of the virus,” said Eran Segal, a computational biologist
at Weizmann who is spearheading the project.
Forecasting areas of
infection would allow officials to flood those places with testing capacity,
Dr. Segal said. And it would allow doctors to better marshal their scant
resources.
“Every
time they test somebody and it’s negative, it’s a wasted test,” he said. “You
want to get positives, act on it, and isolate people.”
The Israeli survey, in
six languages, began by word of mouth, Dr. Segal said. But this week, Israel’s
largest H.M.O., Clalit, sent text messages to its 4.5 million subscribers
pleading with them to participate.
“Help save your loved ones and yourself,” it said.
Dr.
Spector, the director of the TwinsUK
Registry, a nationwide research cohort of 15,000 twins, rolled out
the British survey to that group on March 24, and it spread by word of mouth.
Within five days, he said, the tally of unique participants had surpassed two
million, with the “Covid Symptom Tracker”
app jumping to the No. 1 health-related download in Britain's Apple Store and
the No. 4 app of any kind.
The
survey is popular, but not as evenly distributed as health experts might like.
People over 70 years old are underrepresented, which is not a surprise, given
the app-based distribution. And women are participating at roughly twice the
rate of men. “They are more altruistic, in the U.K.,” Dr. Spector said,
laughing.
Over
all, he said, the respondents in Britain are acting out of concern for the
National Health Service and “a feeling that they’re doing something for the
community.” But he also said that people who reported already having tested
positive for the virus seemed to grasp at the survey as “a way to express their
symptoms.”
“If they don’t go to
hospital, nobody seems to care about them,” Dr. Spector said.
Surveys are not the only unconventional way that scientists
are trying to detect the spread of the virus: A maker of smart thermometers
says it is tracking the contagion in real time by mapping fevers in
American households.
In
Britain, the survey suggested that loss of taste and smell could
be more predictive of a positive test result than self-reported fever, fatigue
or loss of appetite, Dr. Spector said. That could be of critical importance to
health workers who may still be going to work despite experiencing a loss of
taste or smell, but isolating themselves based on other symptoms, he said.
But
he emphasized that much was still to be learned.
“This
data’s still wet,” Dr. Spector said. “We have teams of people working on the
analysis to try and get stuff out that’s going to be of critical importance for
the health service.”
Unlike countries with national health systems, the United
States, with its atomized health industry, poses a difficult challenge in
reaching enough respondents to track the epidemic at the local level.
Dr.
Chan’s team, which is adapting the British app for the United States, has
joined with Stand Up to Cancer,
tapping its list of 1.5 million cancer patients and their relatives. It is also
drawing on a research cohort of
about 51,000 female nurses across the country.
Starting with those audiences, Dr. Chan said, offers added
benefits: Both cancer patients and health workers are at particular risk.
In
the M.I.T.-led project, researchers are preparing to promote a survey app that
they developed with the help of engineers from Pinterest, the image-sharing
site, whose co-founder, Ben Silbermann, was a high school classmate in Des
Moines of Feng Zhang, a
biochemist leading the M.I.T. survey effort.
Dr.
Zhang said that he and his colleagues hit on the idea for the surveys just
after they began working from home a few weeks ago. One of them, who had been a
student of Dr. Segal’s in Israel, saw mention of the Israeli survey project,
and the two groups began to coordinate.
Dr.
Zhang and Dr. Segal are already taking their project to other corners of the
globe: A white paper they drafted has co-authors in Argentina, Canada, Estonia,
Germany, Luxembourg, Slovenia, Sweden and Switzerland.
One
area of difference among the surveys concerns privacy.
The
British survey allows people to volunteer personal information, and Dr. Spector
said it might become possible to tie in the survey results to the National
Health Service’s database. The Massachusetts General project allows cancer
patients in clinical trials to provide contact information for their study
physicians if they choose, “to let them know if they are developing symptoms,”
Dr. Chan said.
But
the Israeli questionnaires ask only the name of a respondent’s street, not the
house number. And Olivier Elemento, director of Weill Cornell’s Englander
Institute for Precision Medicine in New York, said its own survey, which includes a dashboard so respondents
can see how the data is used, was deliberately collecting only county-level
information.
“We
want people to feel they can participate without any fear of being identified,”
he said.
The
researchers acknowledge without hesitation that surveys completed by laypeople
without corroboration by scientists or physicians will lack the precision of
more methodical research. But they say widespread participation will produce
enough data to largely overcome the effects of personal variations.
“Given the speed of the pandemic, we don’t have the luxury
of waiting to validate every report we get in from a participant,” said Dr.
Chan, the epidemiologist at Massachusetts General. “We need to act quickly.”
David
D. Celentano, chairman of epidemiology at the Johns Hopkins Bloomberg School of
Public Health, praised the efforts to gather data. “In the U.S., where we had
so little testing till last week, we’ve been completely blind,” he said. “We
have no idea where the epidemic is.”
Dr.
Celentano cautioned that “people who are going to pay attention to their phone
and do this every day are probably either the worried well or people who are
experiencing symptoms, so you’ll have a very biased sample.”
Still,
he said, however flawed, the surveys could be “very useful for targeting where
to put health services.”
Or,
as Mr. Segal put it: “The rule of big numbers means we don’t need to be
super-super-accurate. We just need to be able to rank this region over that
region.”
While
they are racing now to overtake the coronavirus, the researchers say their
survey tools could, alas, come in handy again.
“This has been a lesson in the limitations of our ability
to respond as epidemiologists,” Dr. Chan said of the coronavirus. “We need to
develop tools that will allow us in the future to respond more quickly to data
collection and analysis in real time. Because this may not be the last
pandemic.”
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