INTRODUCTION Although some research papers have suggested that smoking may increase mortality in patients with sepsis, no evidence has been produced in this regard. This systematic research evaluated the risk of death in patients with sepsis who were smokers to facilitate better clinical decision making. METHODS This is a systematic review registered in PROPERO (CRD42022296654). Searches were conducted to identify suitable studies from the databases of PubMed, Embase, Web of Science and the Cochrane Controlled Register of Trials from January 1980 to June 2021. Two independent reviewers screened the articles using keywords and extracted the data. The Newcastle–Ottawa Scale (NOS) was used to evaluate the quality of evidence. The primary endpoints included the mortality of patients with sepsis. RESULTS Five studies involving 2694 participants were included in our study. Among the five included articles, three studies had an NOS score of 6, while the other two had an NOS score of 7. The results showed that a significantly higher risk of death was observed in smokers with sepsis compared with non-smokers with sepsis (hazard ratio, HR=1.62; 95% CI: 1.11–2.37, p=0.01). Among the patients followed for more than 2 months, the mortality rate of smokers was significantly higher (2.33 times) than that of non-smokers (HR=2.33; 95% CI: 1.83–2.96, p<0.01). The difference in mortality did not reach statistical significance when the follow-up period was shorter than 2 months (HR=1.22; 95% CI: 0.96–1.56, p=0.10). CONCLUSIONS Smoking increased mortality in patients with sepsis when the follow-up period was longer than 2 months.

INTRODUCTION Hip fracture is associated with substantial morbidity and mortality, especially among the elderly. Current evidence on the association between cigarette smoking and mortality in hip-fracture patients is controversial. We performed a systematic review and meta-analysis of studies on this association. METHODS The databases Medline/PubMed, Embase, Web of Science, and Cochrane Library were searched for studies that estimated the effect of smoking on the risk of mortality in hip-fracture patients. Pooled analyses were conducted of the associations, expressed in relative risk (RR) and 95% confidence intervals (CIs). Heterogeneity was assessed using the I 2 statistic. Study quality was assessed by the modified Newcastle-Ottawa Scale (NOS) and publication bias was evaluated by a funnel plot, Begg's and Egger's tests. Subgroup analyses were performed by study design, race/ethnicity, age ≥60 years, smoking status, and follow-up period. RESULTS A total of six articles involving 3739 hip-fracture patients were included in the meta-analysis. Our results indicate that ever-active smoking was significantly associated with an increased risk of death in hip-fracture patients (pooled RR=1.26; 95% CI: 1.08-1.46). In further subgroup analysis, the risk of death was significantly higher in ever-active smokers than in never smokers in White participants (pooled RR=1.23; 95% CI: 1.05-1.44) and elderly aged ≥60 years (pooled RR=1.19; 95% CI: 1.01-1.40), with no significant association in Asian participants (pooled RR=1.42; 95% CI: 0.95-2.11). Current smokers had more risk of death than never smokers (pooled RR=1.26; 95% CI: 1.08-1.46). The association was significant in follow-up periods of ≤1 year (pooled hazard ratio, HR=1.34; 95% CI: 1.05-1.71), 3 years (pooled HR=1.22; 95% CI: 1.05-1.43), and 5 years (pooled HR=1.26; 95% CI: 1.08-1.46). CONCLUSIONS Cigarette smoking is associated with an increased risk of mortality in hip-fracture patients, especially in elderly patients aged ≥60 years, current smokers, and White participants. With the extension of follow-up period, the effect on mortality of smoking is profound and lasting.