Current situation Trends in key drivers of transmission (mobility, … · 2020. 9. 11. · Current situation • The decline in national case numbers seen since late July flattened

United States Model updates for September 11, 2020

covid.healthdata.org Institute for Health Metrics and Evaluation

COVID-19 remained steady in the US over the last week while mobility and mask use continued to worsen. We expect a major surge in daily cases and deaths in November and December driven by seasonality and decreased vigilance.

Current situation

• The decline in national case numbers seen since late July flattened in the last week (Figure 1). • Daily deaths have been relatively constant around 850 per day over the past week so that COVID-19 remains the

number two cause of death in the US (Figure 2 and Table 1). • States where the combination of data on cases, hospitalizations, and deaths suggest that transmission is

increasing has shifted to Alabama, Colorado, Hawaii, Kansas, Missouri, New Jersey, New York, Virginia, and West Virginia (Figure 3).

• States where the COVID-19 death rate is over 4 per million are in a contiguous block from Texas through to South Carolina (Figure 6).

Trends in key drivers of transmission (mobility, mask use, testing, and seasonality)

• Evidence is consistently emerging that the US is becoming less vigilant. Mobility has been rising since August 1, albeit slowly (Figure 8).

• Mask use, as measured in the PREMISE surveys based on the response category of “always wear a mask when leaving home,” has also been declining steadily since August 1. Only six states have mask use over 50% at this point: Alaska, California, Florida, Hawaii, Texas, and Virginia (Figure 9).

Projections

• We expect the daily death rate in the US, because of seasonality and declining public vigilance, to reach nearly 3,000 a day in December. Cumulative deaths expected by January 1 are 415,090; this is 222,522 deaths from now until the end of the year.

• The large increase in daily deaths expected in late November and December is driven by continued increases in mobility, declines in mask use, and – most importantly – seasonality. We estimate the likely impact of seasonality by examining the trends in the Northern and Southern Hemisphere. For example, Southern Hemisphere countries such as Argentina, Chile, southern Brazil, and South Africa had much larger epidemics than expected based on mobility, testing, and mask use. The statistical association between COVID-19 transmission rates and pneumonia seasonality patterns is strong and is the basis for our estimate of the magnitude of the seasonal increase that is expected.

• If a herd immunity strategy is pursued, meaning no further government intervention is taken from now to January 1, then the death toll could increase to 611,784 by January 1. Compared to the reference scenario, this would be 196,694 more deaths from now to the end of the year.

• Increasing mask use remains an extraordinary opportunity for the US. Increasing mask use to the levels seen in Singapore would decrease the cumulative US death toll to 298,589, or 116,501 lives saved compared to the reference scenario.

Model updates

• Clinical experience suggests that case management of COVID-19 has improved through oxygenation/ventilation methods and use of dexamethasone and remdesivir. This improved management would manifest itself as a reduction in the infection-fatality rate at each age. We have looked for statistical evidence of this shift in two ways. First, we have examined the COVID-19 admission-fatality rate – the number of deaths divided by hospital admissions. To date, the admission-fatality rate has remained constant since April. This could be explained by

United States Model updates for September 11, 2020

covid.healthdata.org Institute for Health Metrics and Evaluation

two possible factors: either there is no change in the infection-fatality rate or the infection-fatality rate has declined and hospitals are admitting only more severe patients over time. Second, we have looked at the directly measured infection-fatality rate using seroprevalence studies. To date, we have not detected any statistically significant decrease in the infection-fatality rate. We will continue testing on a regular basis for statistical evidence of the infection-fatality rate declining.

United States of America MODEL UPDATES

COVID-19 Results Briefing: United States of America

Institute for Health Metrics and Evaluation (IHME)

September 11, 2020

This briefing contains summary information on the latest projections from the IHME model on COVID-19 inUnited States of America. The model was run on September 10, 2020.

Model updates

Updates to the model this week include additional data on deaths, cases, and updates on covariates.

covid19.healthdata.org 1 Institute for Health Metrics and Evaluation

United States of America CURRENT SITUATION

Current situation

Figure 1. Reported daily COVID-19 cases

0

20,000

40,000

60,000

80,000

Apr May Jun Jul Aug SepMonth

Cou

nt

Daily cases



Table 1. Ranking of COVID-19 among the leading causes of mortality this week, assuming uniform deathsof non-COVID causes throughout the year

Cause name Weekly deaths RankingIschemic heart disease 10,724 1COVID-19 5,984 2Tracheal, bronchus, and lung cancer 3,965 3Chronic obstructive pulmonary disease 3,766 4Stroke 3,643 5Alzheimer’s disease and other dementias 2,768 6Chronic kidney disease 2,057 7Colon and rectum cancer 1,616 8Lower respiratory infections 1,575 9Diabetes mellitus 1,495 10

Figure 2a. Reported daily COVID-19 deaths and smoothed trend estimate

0

1,000

2,000

Apr May Jun Jul Aug Sep

Dai

ly d

eath

s



Figure 2b. Estimated cumulative deaths by age group

0

5

10

15

<5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 99Age group

Sha

re o

f cum

ulat

ive

deat

hs, %

Figure 3. Mean effective R on August 28, 2020. The estimate of effective R is based on the combined analysisof deaths, case reporting and hospitalizations where available. Current reported cases reflect infections 11-13days prior so estimates of effective R can only be made for the recent past. Effective R less than 1 meansthat transmission should decline all other things being held the same.

<0.84

0.84−0.87

0.88−0.91

0.92−0.95

0.96−0.99

1−1.03

1.04−1.07

1.08−1.11

1.12−1.15

>=1.16



Figure 4. Estimated percent infected with COVID-19 on September 08, 2020

<1

1−3.9

4−6.9

7−9.9

10−12.9

13−16.4

16.5−19.4

19.5−22.4

22.5−25.4

>=25.5

Figure 5. Percent of COVID-19 infections detected. This is estimated as the ratio of reported COVID-19cases to estimated COVID-19 infections based on the SEIR model.

0

20

40

Feb Mar Apr May Jun Jul Aug Sep

Per

cent

of i

nfec

tions

det

ecte

d

Republic of Korea Italy United Kingdom United States of America



Figure 6. Daily COVID-19 death rate per 1 million on September 08, 2020

<1

1 to 1.9

2 to 2.9

3 to 3.9

4 to 4.9

5 to 5.9

6 to 6.9

7 to 7.9

>=8


United States of America CRITICAL DRIVERS

Critical drivers

Table 2. Current mandate implementation

All

gath

erin

gs r

estr

icte

d

All

none

ssen

tial b

usin

esse

s cl

osed

Any

bus

ines

ses

rest

ricte

d

Mas

k us

e

Sch

ool c

losu

re

Sta

y ho

me

orde

r

Trav

el li

mits

WyomingWisconsin

West VirginiaWashington

VirginiaVermont

UtahTexas

TennesseeSouth Dakota

South CarolinaRhode IslandPennsylvania

OregonOklahoma

OhioNorth Dakota

North CarolinaNew York

New MexicoNew Jersey

New HampshireNevada

NebraskaMontanaMissouri

MississippiMinnesota

MichiganMassachusetts

MarylandMaine

LouisianaKentucky

KansasIowa

IndianaIllinoisIdaho

HawaiiGeorgiaFlorida

District of ColumbiaDelaware

ConnecticutColoradoCaliforniaArkansas

ArizonaAlaska

Alabama

Mandate in place No mandate



Figure 7. Total number of mandates

WyomingWisconsin

West VirginiaWashington

VirginiaVermont

UtahTexas

TennesseeSouth Dakota

South CarolinaRhode IslandPennsylvania

OregonOklahoma

OhioNorth Dakota

North CarolinaNew York

New MexicoNew Jersey

New HampshireNevada

NebraskaMontanaMissouri

MississippiMinnesota

MichiganMassachusetts

MarylandMaine

LouisianaKentucky

KansasIowa

IndianaIllinoisIdaho

HawaiiGeorgiaFlorida

District of ColumbiaDelaware

ConnecticutColoradoCaliforniaArkansas

ArizonaAlaska

Alabama


# of mandates

0

1

2

3

4

5

6

Mandate imposition timing



Figure 8a. Trend in mobility as measured through smartphone app use compared to January 2020 baseline

−80

−60

−40

−20

0

Jan Feb Mar Apr May Jun Jul Aug Sep

Per

cent

red

uctio

n fr

om a

vera

ge m

obili

ty


Figure 8b. Mobility level as measured through smartphone app use compared to January 2020 baseline(percent)

=<−50

−49 to −45

−44 to −40

−39 to −35

−34 to −30

−29 to −25

−24 to −20

−19 to −15

−14 to −10

>−10



Figure 9a. Trend in the proportion of the population reporting always wearing a mask when leaving home

0

25

50

75

Jan Feb Mar Apr May Jun Jul Aug Sep

Per

cent

of p

opul

atio

n


Figure 9b. Proportion of the population reporting always wearing a mask when leaving home on September08, 2020

<30%

30 to 34%

35 to 39%

40 to 44%

45 to 49%

50 to 54%

55 to 59%

60 to 64%

65 to 69%

>=70



Figure 10a. Trend in COVID-19 diagnostic tests per 100,000 people

0

100

200


Test

per

100

,000

pop

ulat

ion


Figure 10b. COVID-19 diagnostic tests per 100,000 people on September 03, 2020

<5

5 to 9.9

10 to 24.9

25 to 49

50 to 149

150 to 249

250 to 349

350 to 449

450 to 499

>=500



Figure 11. Increase in the risk of death due to pneumonia on February 1 compared to August 1

<−80%

−80 to −61%

−60 to −41%

−40 to −21%

−20 to −1%

0 to 19%

20 to 39%

40 to 59%

60 to 79%

>=80%


United States of America PROJECTIONS AND SCENARIOS

Projections and scenarios

We produce three scenarios when projecting COVID-19. The reference scenario is our forecast of what wethink is most likely to happen. We assume that if the daily mortality rate from COVID-19 reaches 8 permillion, social distancing (SD) mandates will be re-imposed. The mandate easing scenario is what wouldhappen if governments continue to ease social distancing mandates with no re-imposition. The universal maskmandate scenario is what would happen if mask use increased immediately to 95% and social distancingmandates were re-imposed at 8 deaths per million.

Figure 12. Cumulative COVID-19 deaths until January 01, 2021 for three scenarios.

0

200,000

400,000

600,000

0

100

200

300

400

500

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Jan

Cum

ulat

ive

deat

hsC

umulative deaths per 100,000

Continued SD mandate easing

Reference scenario

Universal mask use

Fig 13. Daily COVID-19 deaths until January 01, 2021 for three scenarios.

0

2,500

5,000

7,500

10,000

12,500

0.0

2.5

5.0

7.5

10.0


Dai

ly d

eath

sD

aily deaths per 100,000


Reference scenario

Universal mask use



Fig 14. Daily COVID-19 infections until January 01, 2021 for three scenarios.

0

500,000

1,000,000

1,500,000

0

500

1000

1500


Dai

ly in

fect

ions

Daily infections per 100,000


Reference scenario

Universal mask use

Fig 15. Month of assumed mandate re-implementation. (Month when daily death rate passes 8 per million,when reference scenario model assumes mandates will be re-imposed.)

September

October

November

DecemberNo mandates before Jan 1



Figure 16. Forecasted percent infected with COVID-19 on January 01, 2021

<1

1−3.9

4−6.9

7−9.9

10−12.9

13−16.4

16.5−19.4

19.5−22.4

22.5−25.4

>=25.5

Figure 17. Daily COVID-19 deaths per million forecasted on January 01, 2021 in the reference scenario

<1

1 to 1.9

2 to 2.9

3 to 3.9

4 to 4.9

5 to 5.9

6 to 6.9

7 to 7.9

>=8



Table 3. Ranking of COVID-19 among the leading causes of mortality in the full year 2020. Deaths fromCOVID-19 are projections of cumulative deaths on Jan 1, 2021 from the reference scenario. Deaths fromother causes are from the Global Burden of Disease study 2019 (rounded to the nearest 100).

Cause name Annual deaths RankingIschemic heart disease 557,600 1COVID-19 415,090 2Tracheal, bronchus, and lung cancer 206,200 3Chronic obstructive pulmonary disease 195,800 4Stroke 189,500 5Alzheimer’s disease and other dementias 143,900 6Chronic kidney disease 107,000 7Colon and rectum cancer 84,000 8Lower respiratory infections 81,900 9Diabetes mellitus 77,700 10

Mask data source: Premise; Facebook Global symptom survey (This research is based on survey resultsfrom University of Maryland Social Data Science Center); Kaiser Family Foundation; YouGov COVID-19Behaviour Tracker survey

A note of thanks:

We would like to extend a special thanks to the Pan American Health Organization (PAHO) for keydata sources; our partners and collaborators in Argentina, Brazil, Bolivia, Chile, Colombia, Cuba, theDominican Republic, Ecuador, Egypt, Honduras, Israel, Japan, Malaysia, Mexico, Moldova, Panama, Peru,the Philippines, Russia, Serbia, South Korea, Turkey, and Ukraine for their support and expert advice; andto the tireless data collection and collation efforts of individuals and institutions throughout the world.

In addition, we wish to express our gratitude for efforts to collect social distancing policy information inLatin America to University of Miami Institute for Advanced Study of the Americas (Felicia Knaul, MichaelTouchton), with data published here: http://observcovid.miami.edu/; Fundación Mexicana para la Salud(Héctor Arreola-Ornelas) with support from the GDS Services International: Tómatelo a Pecho A.C.; andCentro de Investigaciones en Ciencias de la Salud, Universidad Anáhuac (Héctor Arreola-Ornelas); Lab onResearch, Ethics, Aging and Community-Health at Tufts University (REACH Lab) and the University ofMiami Institute for Advanced Study of the Americas (Thalia Porteny).

Further, IHME is grateful to the Microsoft AI for Health program for their support in hosting our COVID-19data visualizations on the Azure Cloud. We would like to also extend a warm thank you to the many otherswho have made our COVID-19 estimation efforts possible.


http://observcovid.miami.edu/

Documents

Current situation Trends in key drivers of transmission (mobility, … · 2020. 9. 11. · Current situation • The decline in national case numbers seen since late July flattened