| Zhou et al.9 (2020)Clinical course and risk factors for mortality of adult inpatients with COVID-19 in Wuhan, China: a retrospective cohort study | Jinyintan Hospital and Wuhan Pulmonary Hospital, Wuhan, China | All adult inpatients (aged ≥18 years) with laboratory confirmed COVID-19 (191 patients) | Retrospective multicenter cohort study until 31 January 2020 | Mortality54 patients died during hospitalisation and 137 were discharged | Current smokers: n=11 (6%)Non-survivors: n=5 (9%)Survivors: n=6 (4%)(p=0.20)Current smoker vs non-smokerUnivariate logistic regression(OR=2.23; 95% CI: 0.65–7.63; p=0.2) |
| Zhang et al.10(2020)Clinical characteristics of 140 patients infected with SARS-CoV-2 in Wuhan, China | No. 7 Hospital of Wuhan, China | All hospitalised patients clinically diagnosed as ‘viral pneumonia’ based on their clinical symptoms with typical changes in chest radiology (140 patients) | Retrospective 16 January to 3 February 2020 | Disease SeverityNon-severepatients: n=82Severe patients:n=58 | Disease SeverityFormer smokers: n=7Severe: n=4 (6.9%)Non-severe: n=3 (3.7%) (p= 0.448)Current smokers: n=2Severe: n=2 (3.4%)Non-severe: n=0 (0%) |
| Guan et al.12(2019)Clinical Characteristics of Coronavirus Disease 2019 in China | 552 hospitals in 30 provinces, autonomous regions, and municipalities in mainland China | Patients with laboratory-confirmed COVID-19 (1099 patients) | Retrospective until 29 January 2020 | Severity and admission to an ICU, the use of mechanical ventilation, or deathNon-severe patients: n=926 Severe patients: n=173 | By severitySevere cases16.9% current smokers5.2% former smokers77.9% never smokersNon-severe cases11.8% current smokers1.3% former smokers86.9% never smokersBy mechanical ventilation, ICU or deathNeeded mechanical ventilation, ICU or died25.8% current smokers7.6% former smokers66.7% non-smokersNo mechanical ventilation, ICU or death11.8% current smokers1.6% former smokers86.7% never smokers |
| Huang et al.11(2020)Clinical features of patients infected with 2019 novel coronavirus in Wuhan, China | A hospital in Wuhan, China | Laboratory-confirmed 2019-nCoV patients in Wuhan (41 patients) | Prospective from 16 December 2019 to 2 January 2020 | MortalityAs of 22 January 2020, 28 (68%) of 41 patients were discharged and 6 (15%) patients died | Current smokers: n=3ICU care: n=0Non-ICU care: n=3 (11%)Current smokers in ICU care vs non-ICU care patients (p=0.31) |
| Liu et al.13 (2019)Analysis of factors associated with disease outcomes in hospitalised patients with 2019 novel coronavirus disease | Three tertiary hospitals in Wuhan, China | Patients tested positive for COVID-19 (78 patients) | Retrospective multicentre cohort study from 30 December 2019 to 15 January 2020 | Disease progression11 patients (14.1%) in the progression group 67 patients (85.9%) in the improvement/stabilization group 2 deaths | Negative progression group: 27.3% smokersIn the improvement group: 3% smokersThe negative progression group had a significantly higher proportion of patients with a history of smoking than the improvement/stabilisation group (27.3% vs 3.0%)Multivariate logistic regression analysis indicated that the history of smoking was a risk factor of disease progression (OR=14.28; 95% CI: 1.58–25.00; p= 0.018) |