1/4

So far all existing data show smokers are underrepresented in Covid19 hospitalization data

2 studies from the US

1. https://www.medrxiv.org/content/10.1101/2020.04.08.20057794v1

2. https://twitter.com/phil_w888/status/1245115268910559232
2/4

13 studies from China

https://www.qeios.com/read/article/561
5/4

The data consistently show that former smokers are more at risk of serious outcomes than current smokers.
6/4
7/4 More from France

"Our cross sectional study in both COVID-19 out- and inpatients strongly suggests that current smokers have a very much lower probability of developing symptomatic or severe SARS-CoV-2 infection as compared to the general population" https://www.qeios.com/read/article/569
8/

West Virginia USA: Current smoking rate was 25.2% in 2018.

Source (slide 6) https://dhhr.wv.gov/COVID-19/Pages/default.aspx
9/ US Veterans Age 54-75

"Current smoking (OR 0.45, 95% CI 0.35-0.57), alcohol use disorder (OR 232 0.58, 95% CI 0.41- 0.83), and COPD (OR 0.67, 95%CI 0.50-0.88) were associated with decreased likelihood of Covid-19+."

https://www.medrxiv.org/content/10.1101/2020.04.09.20059964v1.full.pdf
10/

France

"The protection associated with smoking in our study was very substantial (75% decrease in risk of infection), and deserves full attention."

https://www.medrxiv.org/content/10.1101/2020.04.18.20071134v1.full.pdf
12/

Oregon USA (adult smoking rate was 15.6% in 2019)

Out of 73 deaths, only one was a smoker.

https://govsite-assets.s3.amazonaws.com/U2Ui9gUiSxG1oSnXa3hf_COVID-19-Weekly-Report-2020-04-28-FINAL.pdf
13/

1536 patients at 169 hospitals (121 in US, 48 in 10 other countries)

"5.5% were current smokers"

Smoking rates in all 11 countries are considerably higher.

https://www.nejm.org/doi/full/10.1056/NEJMoa2007621
14/

Korea (adult smoking rate was 21.1% in 2018)

Small study: Of 27 hospitalized, 5 (18.5%) were smokers.

https://jkms.org/DOIx.php?id=10.3346/jkms.2020.35.e142
16/

UK (adult smoking rate was 14.7% in 2018)

Large study: Of 5,564 deaths, 7% were smokers.

https://www.medrxiv.org/content/10.1101/2020.05.06.20092999v1.full.pdf
17/

Italy (adult smoking rate was 23.7% in 2016)

Of 441 hospitalized patients, 4.8% were smokers.

https://www.medrxiv.org/content/10.1101/2020.05.05.20092015v1.full.pdf
20/

New York City, USA (adult smoking rate was 13.4% in 2017)

Of 393 hospitalized patients, 5.1% were current smokers

(There might be some overlap between this study & the study in the first tweet of this thread) https://www.nejm.org/doi/full/10.1056/NEJMc2010419
21/

Switzerland (adult smoking rate was 27.1% in 2017)

Of 200 hospitalized patients, 4.5% were smokers.

https://www.medrxiv.org/content/10.1101/2020.05.11.20097741v1.full.pdf
22/

Mexico (adult smoking rate was 17.6% in 2016)

Of 10,544 cases, 8.96% were smokers.

https://www.medrxiv.org/content/10.1101/2020.05.11.20098145v1.full.pdf
23/

Kuwait (adult smoking rate was 22.5% in 2015)

Of 1,096 hospitalized cases, 4% were smokers.

Note: sample was 81% male. Male smoking rate in Kuwait was 43% in 2018.

https://www.medrxiv.org/content/10.1101/2020.05.09.20096495v1.full.pdf
25/

3,799 patients in the UK

Smokers were half as likely as non-smokers to test positive for COVID-19

https://www.thelancet.com/journals/laninf/article/PIIS1473-3099(20)30371-6/fulltext
26/

China (adult smoking rate was 26.6% in 2018)

Of 121 hospitalized patients, 5% were smokers.

https://www.medrxiv.org/content/10.1101/2020.05.12.20099739v1.full.pdf
28/

China (adult smoking rate was 26.6% in 2018)

Of 285 hospitalized patients, 11% had a history of smoking.

https://www.researchsquare.com/article/rs-27390/v1
29/

China (adult smoking rate was 26.6% in 2018)

Of 208 hospitalized patients, 5.8% were smokers

https://www.researchsquare.com/article/rs-23842/v1
30/

China (adult smoking rate was 26.6% in 2018)

Of 220 hospitalized patients, 12.8% had a history of smoking. This one includes smoking index data. Smoking index number is cigarettes per day x years smoked.

https://www.researchsquare.com/article/rs-26776/v1
31/

China (adult smoking rate was 26.6% in 2018)

Of 134 hospitalized patients, 10.4% were smokers.

https://www.researchsquare.com/article/rs-26416/v1
32/

China (adult smoking rate was 26.6% in 2018)

Of 142 hospitalized patients, 9.1% were smokers

https://www.researchsquare.com/article/rs-23614/v1
33/

Very small study from China

"Based on the expression of ACE2 in smoking individuals, it is inferred that long-term smoking might be a risk factor for 2019-nCoV, and in this study, We showed the evidence against that finding."

https://www.researchsquare.com/article/rs-24743/v1
34/

China (adult smoking rate was 26.6% in 2018)

Reported: "There were more smokers (8.84% vs 1.36%, P = 0.006)...in the severe group than in the mild group."

Not mentioned: 5.1% of the 292 hospitalized patients had a history of smoking.

https://www.researchsquare.com/article/rs-23272/v1
35/

New Mexico USA (adult smoking rate was 17.5% in 2017)

An outlier. Of 50 hospitalized patients, 48% were smokers. It's not clear whether current smokers or people with a history of smoking were counted.

https://www.medrxiv.org/content/10.1101/2020.05.15.20094284v1.full.pdf
36/

China (adult smoking rate was 26.6% in 2018)

Of 101 hospitalized medical staff, 4 were smokers.

https://www.researchsquare.com/article/rs-28753/v1
37/

Spain (adult smoking rate was 24% in 2019)

Of 54 patients with inflammatory rheumatic disease who were hospitalized with Covid-19, 5.56% were smokers.

https://www.medrxiv.org/content/10.1101/2020.05.14.20101584v1.full.pdf
38/

France (adult daily smoking rate was 27% in 2017)

Of 108 cancer patients who tested positive, 19% were active smokers.

https://www.medrxiv.org/content/10.1101/2020.05.14.20101576v1.full.pdf
39/

London, UK (adult smoking rate was 13.9% in 2018)

Of 75 cancer patients who tested positive, 9.3% were current smokers.

https://www.medrxiv.org/content/10.1101/2020.05.12.20094219v1.full.pdf
40/

North Carolina, USA (adult smoking rate was 17.4% in 2019)

Of 86 hospitalized patients, 3.5% were current or former smokers.

https://www.medrxiv.org/content/10.1101/2020.05.14.20099234v1.full.pdf
46/

UK

"...we observed an apparently protective effect, in the tested sub-population, of smoking on the risk of having a positive PCR for SARS-CoV-2 infection (OR [95% CI] 0.73 [0.65 to 0.81]; p=9.49x10-9)..."

No hospitalization data reported.

https://www.medrxiv.org/content/10.1101/2020.05.18.20105288v1.full.pdf
47/

China (adult male smoking rate was 50.5% in 2018)

Of 125 male patients with mild symptoms, 65.6% were current smokers.

Notes:
Median age was 35
Patients with severe symptoms were excluded from study

https://www.researchsquare.com/article/rs-29526/v1
48/

China (adult smoking rate was 26.6% in 2018)

Of 50 critically ill patients admitted to ICU, 18% were current smokers

https://www.researchsquare.com/article/rs-29681/v1
49/

New York City, USA (adult smoking rate was 13.4% in 2017)

Of 5,051 patients diagnosed with Covid-19, 3.6% were current smokers

https://www.medrxiv.org/content/10.1101/2020.05.19.20103036v1.full.pdf
51/

Monterey County, California, USA (adult smoking rate was 11.7% in 2017)

Of 362 confirmed cases, 4% were current or former smokers

https://www.co.monterey.ca.us/government/departments-a-h/health/diseases/2019-novel-coronavirus-2019-ncov/2019-novel-coronavirus-2019-ncov-local-data
52/

China (adult smoking rate was 26.6% in 2018)

Of 307 hospitalized patients, 21.8% had a history of smoking

https://www.researchsquare.com/article/rs-30347/v1
53/

China (adult smoking rate was 26.6% in 2018)

Of 201 hospitalized patients, 7.0% had a history of smoking

https://www.researchsquare.com/article/rs-30438/v1
54/

Milan, Italy (adult smoking rate was 19% in 2017)

Of 222 hospitalized patients, 11.2% had a "smoke habit"

https://www.researchsquare.com/article/rs-30481/v1
55/

Israel (adult smoking rate was 19.1% in 2018)

Of 4,353 people who tested positive, 11.8% were current smokers

https://www.medrxiv.org/content/10.1101/2020.05.07.20091652v2.full.pdf
56/

New York City, USA (adult smoking rate was 13.4% in 2017)

Of 1,000 who tested positive, 4.9% were active smokers

Of 850 hospitalized, 4.12% were active smokers

Of 236 in ICU, 4.2% were active smokers

https://www.medrxiv.org/content/10.1101/2020.04.20.20072116v2.full.pdf
56a/

There appears to be a considerable amount of overlap between the studies in tweet 56 & tweet 45.
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