The role of secondhand smoke in sinusitis: A systematic review

Background: The objective of this study was to systematically review existing literature on the association between sinusitis and secondhand smoke (SHS) exposure. Methods: We performed a literature search encompassing the last 25 years in PubMed, EMBASE, and Cochrane CENTRAL. Inclusion criteria included English language papers containing original human data with at least 7 subjects. Data was systematically collected on study design, patient demographics, clinical characteristics/outcomes, and level-of-evidence (Oxford Center for Evidence-Based Medicine). Quality assessment was performed using the Newcastle-Ottawa scale. Two investigators independently reviewed all manuscripts. Results: The initial search yielded 116 abstracts, of which 19 articles were included. Thirteen (68.4%) of the 19 articles showed a statistically significant association between sinusitis and SHS. Seven (36.8%) studies specifically evaluated chronic rhinosinusitis (CRS) with 5 (71.4%) CRS studies demonstrating a significant association between CRS and SHS. Seventeen articles were case-control studies (Level 3b). For characterizing sinusitis, 6 (31.6%) studies included computed tomography (CT) or endoscopy in the diagnostic criteria, with 5 of these studies following rhinosinusitis taskforce guidelines. For determining presence of SHS, all studies used questionnaires and 2 (10.5%) studies also reported serum or urine cotinine levels. Conclusion: A majority of the studies (68.4%) included in this systematic review showed a significant association between sinusitis and SHS.