Table 1.
Demographic characteristics, severity scales and clinical variables in smokers and non-smokers among the studied patients
| Variables | All n (%) | Non-smokers n (%) | Smokers n (%) | p |
|---|---|---|---|---|
| Gender | <0.001 | |||
| Male | 1722 (48.91) | 1331 (45.23) | 391 (67.65) | |
| Female | 1799 (51.09) | 1612 (54.77) | 187 (32.35) | |
| Age (years), median (IQR) | 62 (47–78) | 60 (45–78) | 68 (56–78) | <0.001 |
| Health worker | 667 (19.80) | 582 (20.70) | 85 (15.15) | 0.003 |
| Housing conditions | 0.104 | |||
| Not known | 3162 (90.60) | 2640 (90.44) | 522 (91.42) | |
| Residence | 314 (8.99) | 270 (9.25) | 44 (7.71) | |
| Hostel | 13 (0.37) | 8 (0.27) | 5 (0.88) | |
| Prison | 1 (0.03) | 1 (0.03) | 0 (0.00) | |
| Relationship with COVID-19 positive | 554 (17.09) | 471 (17.32) | 83 (15.96) | 0.452 |
| Suspected nosocomial transmission | 1064 (30.56) | 894 (30.75) | 170 (29.62) | 0.589 |
| Functional stage a | 0.101 | |||
| Dependent for basic activities of daily living | 252 (7.44) | 222 (7.86) | 30 (5.36) | |
| Semi-dependent for basic activities of daily living | 190 (5.61) | 155 (5.49) | 35 (6.25) | |
| Independent for basic activities of daily living | 2942 (86.94) | 2447 (86.65) | 495 (88.39) | |
| Charlson comorbidity index, median (IQR) b | 2 (0–5) | 2 (0–4) | 4 (2–6) | <0.001 |
| Severity scales, mean ± SDc | ||||
| CURB-65 | 1.06 ± 1.14 | 1.02 ± 1.14 | 1.27 ± 1.15 | <0.001 |
| FINE | 2.19 ± 1.59 | 2.06 ± 1.52 | 2.88 ± 1.86 | 0.084 |
| qSOFA | 0.33 ± 0.61 | 0.32 ± 0.60 | 0.38 ± 0.70 | 0.081 |
| SOFA | 0.57 ± 1.74 | 0.64 ± 1.93 | 0.27 ± 0.46 | 0.892 |
| PSI | 4.24 ± 14.75 | 4.85 ± 15.88 | 0.63 ± 1.77 | 0.015 |
| Need for oxygen therapy on admission | 2178 (63.22) | 1176 (61.80) | 402 (70.53) | <0.001 |
| Type of oxygen therapy | <0.001 | |||
| Venturi mask | 178 (8.18) | 144 (8.12) | 34 (8.46) | |
| Single mask | 14 (0.64) | 12 (0.68) | 2 (0.50) | |
| Nasal goggles | 1170 (53.79) | 994 (56.06) | 176 (43.78) | |
| Mask with reservoir | 567 (26.07) | 442 (24.93) | 125 (31.09) | |
| Non-invasive mechanical ventilation | 109 (5.01) | 74 (4.17) | 35 (8.71) | |
| Invasive mechanical ventilation | 137 (6.30) | 107 (6.03) | 30 (7.46) | |
| Use of pronation technique and prone position | 188 (6.43) | 137 (5.63) | 51 (10.41) | <0.001 |
| Respiratory rate, median (IQR) | 18 (18–20) | 18 (18–18) | 18 (18–30) | 0.002 |
| Need for admission to ICU | 173 (5.08) | 138 (4.86) | 35 (6.22) | 0.180 |
a
Functional stage of a patient refers to the dependency to perform basic daily activities.
b
The Charlson comorbidity index is used for assessing life expectancy at ten years, depending on the age at which it is assessed and the subject’s comorbidities. It is widely used in clinical studies to adjust for poor patient prognosis.
c
Severity scales measured on admission. IQR: interquartile range.
ICU: intensive care unit.