Current smoking, former smoking, and adverse outcome among hospitalized COVID-19 patients: a systematic review and meta-analysis
Background: The purpose of this study was to examine the prevalence and effects of current smoking on adverse outcomes among hospitalized COVID-19 patients. Methods: A systematic review of the literature (PubMed) identified 18 (from a total of 1398) relevant studies. Pooled current smoking prevalenc...
| Main Authors: | , , , , , |
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| Format: | Article |
| Language: | English |
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SAGE Publishing
2020-06-01
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| Series: | Therapeutic Advances in Chronic Disease |
| Online Access: | https://doi.org/10.1177/2040622320935765 |
| _version_ | 1819131582057807872 |
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| author | Konstantinos Farsalinos Anastasia Barbouni Konstantinos Poulas Riccardo Polosa Pasquale Caponnetto Raymond Niaura |
| author_facet | Konstantinos Farsalinos Anastasia Barbouni Konstantinos Poulas Riccardo Polosa Pasquale Caponnetto Raymond Niaura |
| author_sort | Konstantinos Farsalinos |
| collection | DOAJ |
| description | Background: The purpose of this study was to examine the prevalence and effects of current smoking on adverse outcomes among hospitalized COVID-19 patients. Methods: A systematic review of the literature (PubMed) identified 18 (from a total of 1398) relevant studies. Pooled current smoking prevalence was compared with the gender-adjusted and gender and age-adjusted, population-based expected prevalence by calculating prevalence odds ratio (POR). The association between current, compared with non-current and former, smoking and adverse outcome was examined. A secondary analysis was performed by including 12 pre-publications (30 studies in total). All analyses were performed using random-effects meta-analysis. Results: Among 6515 patients, the pooled prevalence of current smoking was 6.8% [95% confidence interval (CI): 4.8–9.1%]. The gender-adjusted POR was 0.20 (95% CI: 0.16–0.25, p < 0.001), and the gender and age-adjusted POR was 0.24 (95% CI: 0.19–0.30, p < 0.001). Current smokers were more likely to have an adverse outcome compared with non-current smokers [odds ratio (OR): 1.53, 95%CI: 1.06–2.20, p = 0.022] but less likely compared with former smokers (OR: 0.42, 95% CI: 0.27–0.74, p = 0.003). When pre-publications were added ( n = 10,631), the gender-adjusted POR was 0.27 (95% CI: 0.19–0.38, p < 0.001) and the gender and age-adjusted POR was 0.34 (95% CI: 0.24–0.48, p < 0.001). Conclusion: This meta-analysis of retrospective observational case series found an unexpectedly low prevalence of current smoking among hospitalized patients with COVID-19. Hospitalized current smokers had higher odds compared with non-current smokers but lower odds compared with former smokers for an adverse outcome. Smoking cannot be considered a protective measure for COVID-19. However, the hypothesis that nicotine may have a protective effect in COVID-19 that is partially masked by smoking-related toxicity and by the abrupt cessation of nicotine intake when smokers are hospitalized should be explored in laboratory studies and clinical trials using pharmaceutical nicotine products. |
| first_indexed | 2024-12-22T09:17:47Z |
| format | Article |
| id | doaj.art-d00ff6d3011d4bdc839475714f4409f9 |
| institution | Directory Open Access Journal |
| issn | 2040-6231 |
| language | English |
| last_indexed | 2024-12-22T09:17:47Z |
| publishDate | 2020-06-01 |
| publisher | SAGE Publishing |
| record_format | Article |
| series | Therapeutic Advances in Chronic Disease |
| spelling | doaj.art-d00ff6d3011d4bdc839475714f4409f92022-12-21T18:31:16ZengSAGE PublishingTherapeutic Advances in Chronic Disease2040-62312020-06-011110.1177/2040622320935765Current smoking, former smoking, and adverse outcome among hospitalized COVID-19 patients: a systematic review and meta-analysisKonstantinos FarsalinosAnastasia BarbouniKonstantinos PoulasRiccardo PolosaPasquale CaponnettoRaymond NiauraBackground: The purpose of this study was to examine the prevalence and effects of current smoking on adverse outcomes among hospitalized COVID-19 patients. Methods: A systematic review of the literature (PubMed) identified 18 (from a total of 1398) relevant studies. Pooled current smoking prevalence was compared with the gender-adjusted and gender and age-adjusted, population-based expected prevalence by calculating prevalence odds ratio (POR). The association between current, compared with non-current and former, smoking and adverse outcome was examined. A secondary analysis was performed by including 12 pre-publications (30 studies in total). All analyses were performed using random-effects meta-analysis. Results: Among 6515 patients, the pooled prevalence of current smoking was 6.8% [95% confidence interval (CI): 4.8–9.1%]. The gender-adjusted POR was 0.20 (95% CI: 0.16–0.25, p < 0.001), and the gender and age-adjusted POR was 0.24 (95% CI: 0.19–0.30, p < 0.001). Current smokers were more likely to have an adverse outcome compared with non-current smokers [odds ratio (OR): 1.53, 95%CI: 1.06–2.20, p = 0.022] but less likely compared with former smokers (OR: 0.42, 95% CI: 0.27–0.74, p = 0.003). When pre-publications were added ( n = 10,631), the gender-adjusted POR was 0.27 (95% CI: 0.19–0.38, p < 0.001) and the gender and age-adjusted POR was 0.34 (95% CI: 0.24–0.48, p < 0.001). Conclusion: This meta-analysis of retrospective observational case series found an unexpectedly low prevalence of current smoking among hospitalized patients with COVID-19. Hospitalized current smokers had higher odds compared with non-current smokers but lower odds compared with former smokers for an adverse outcome. Smoking cannot be considered a protective measure for COVID-19. However, the hypothesis that nicotine may have a protective effect in COVID-19 that is partially masked by smoking-related toxicity and by the abrupt cessation of nicotine intake when smokers are hospitalized should be explored in laboratory studies and clinical trials using pharmaceutical nicotine products.https://doi.org/10.1177/2040622320935765 |
| spellingShingle | Konstantinos Farsalinos Anastasia Barbouni Konstantinos Poulas Riccardo Polosa Pasquale Caponnetto Raymond Niaura Current smoking, former smoking, and adverse outcome among hospitalized COVID-19 patients: a systematic review and meta-analysis Therapeutic Advances in Chronic Disease |
| title | Current smoking, former smoking, and adverse outcome among hospitalized COVID-19 patients: a systematic review and meta-analysis |
| title_full | Current smoking, former smoking, and adverse outcome among hospitalized COVID-19 patients: a systematic review and meta-analysis |
| title_fullStr | Current smoking, former smoking, and adverse outcome among hospitalized COVID-19 patients: a systematic review and meta-analysis |
| title_full_unstemmed | Current smoking, former smoking, and adverse outcome among hospitalized COVID-19 patients: a systematic review and meta-analysis |
| title_short | Current smoking, former smoking, and adverse outcome among hospitalized COVID-19 patients: a systematic review and meta-analysis |
| title_sort | current smoking former smoking and adverse outcome among hospitalized covid 19 patients a systematic review and meta analysis |
| url | https://doi.org/10.1177/2040622320935765 |
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