SynthesisInternal and emergency medicine2020
Systematic review of the prevalence of current smoking among hospitalized COVID-19 patients in China: could nicotine be a therapeutic option?
Synthesis in Internal and emergency medicine, 2020. The graph could read no effect estimate from its abstract, so it casts no vote on the map. It is linked to trial NCT04896918 (Smoking, Snus Use and the Risk of COVID-19 in a Cohort of Adult Client of Public Dentistry Clinics), which is not on this map. Cited by 178 papers, 8 of them syntheses that pooled it.
What it found
Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.
The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
Smoking, Snus Use and the Risk of COVID-19 in a Cohort of Adult Client of Public Dentistry Clinics: is There a Causal Association?
Who cites it
178 citing papers in PubMed, 8 syntheses or guidelines pooled it, 316 citations in OpenAlex.
- Differences in clinical characteristics between coronavirus disease 2019 (COVID-19) and influenza: a systematic review and meta-analysis.NPJ primary care respiratory medicine · 2025Pooled it
- Smoking is associated with worse outcomes of COVID-19 particularly among younger adults: a systematic review and meta-analysis.BMC public health · 2021Pooled it
- The association of smoking status with SARS-CoV-2 infection, hospitalization and mortality from COVID-19: a living rapid evidence review with Bayesian meta-analyses (version 7).Addiction (Abingdon, England) · 2021Pooled it
- The effect of smoking on COVID-19 severity: A systematic review and meta-analysis.Journal of medical virology · 2021Pooled it
- Smoking prevalence among hospitalized COVID-19 patients and its association with disease severity and mortality: an expanded re-analysis of a recent publication.Harm reduction journal · 2021Pooled it
- Population risk factors for severe disease and mortality in COVID-19: A global systematic review and meta-analysis.PloS one · 2021Pooled it
- A Systematic Review and Meta-Analysis of Hospitalised Current Smokers and COVID-19.International journal of environmental research and public health · 2020Pooled it
- The Effect of Smoking on COVID-19 Symptom Severity: Systematic Review and Meta-Analysis.Pulmonary medicine · 2020Pooled it
- Nicotine patches in patients on mechanical ventilation for severe COVID-19: a randomized, double-blind, placebo-controlled, multicentre trial.Intensive care medicine · 2022Trial
- SARS-CoV-2 serology in 4000 health care and administrative staff across seven sites in Lombardy, Italy.Scientific reports · 2021Trial
- Quit Experiences among Primary Care Patients Enrolled in a Smoking Cessation Pilot RCT Early in the COVID-19 Pandemic.International journal of environmental research and public health · 2021Trial
- Nicotine and cotinine enhance SARS-CoV-2 entry through distinct but complementary mechanisms in human respiratory epithelial cells.Journal of virology · 2026Article
- Impact of Smoking on Household SARS-CoV-2 Transmission.Healthcare (Basel, Switzerland) · 2026Article
- Article
- Clinical Characteristics and Mortality Trends Among COVID-19 Patients During the First Four Waves in Ngaliema Clinic, Democratic Republic of the Congo.Infection and drug resistance · 2025Article
- Google Trends Assessment of Keywords Related to Smoking and Smoking Cessation During the COVID-19 Pandemic in 4 European Countries: Retrospective Analysis.Online journal of public health informatics · 2024Article
- Protecting effects of smoking against COVID-19: a community-based retrospective cohort study in middle- and older-aged adults.Internal and emergency medicine · 2024Article
- Regulation of Inflammation by IRAK-M Pathway Can Be Associated with nAchRalpha7 Activation and COVID-19.Molecular neurobiology · 2024Review
- Exploring the Impact of COVID-19 on Ulcerative Colitis Patients: A Lifestyle Perspective.Medicina (Kaunas, Lithuania) · 2024Article
- The Association of Smoking and SARS-CoV-2 Infection.Tanaffos · 2024Article
118 more citing papers are in PubMed but not listed here.
Corrections and comments
- Commented on by
- Commented on by
- Commented on by
Authors and funding
3 authors at 2 institutions in 2 countries.
Funding
No grant is acknowledged in the PubMed record.
Abstract
The effects of smoking on Corona Virus Disease 2019 (COVID-19) are currently unknown. The purpose of this study was to systematically examine the prevalence of current smoking among hospitalized patients with COVID-19 in China, considering the high-population smoking prevalence in China (26.6%). A systematic review of the literature (PubMed) was performed on April 1. Thirteen studies examining the clinical characteristics of hospitalized COVID-19 patients in China and presenting data on the smoking status were found. The pooled prevalence of current smoking from all studies was calculated by random-effect meta-analysis. To address the possibility that some smokers had quit shortly before hospitalization and were classified as former smokers on admission to the hospital, we performed a secondary analysis in which all former smokers were classified as current smokers. A total of 5960 patients were included in the studies identified. The current smoking prevalence ranged from 1.4% (95% CI 0.0-3.4%) to 12.6% (95% CI 10.6-14.6%). An unusually low prevalence of current smoking was observed from the pooled analysis (6.5%, 95% CI 4.9-8.2%) as compared to population smoking prevalence in China. The secondary analysis, classifying former smokers as current smokers, found a pooled estimate of 7.3% (95% CI 5.7-8.9%). In conclusion, an unexpectedly low prevalence of current smoking was observed among patients with COVID-19 in China, which was approximately 1/4th the population smoking prevalence. Although the generalized advice to quit smoking as a measure to reduce health risk remains valid, the findings, together with the well-established immunomodulatory effects of nicotine, suggest that pharmaceutical nicotine should be considered as a potential treatment option in COVID-19.
Indexed as
Identifiers
What OpenQuestion holds
Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.