Clinical features, radiological findings, and mortality in patients with e-cigarette or vaping product use-associated lung injury: a systematic review and meta-analysis

OBJECTIVE: To evaluate the clinical features, radiological findings, and mortality in patients with e-cigarette or vaping product use-associated lung injury (EVALI). METHODS: A systematic search was conducted in Medline/PubMed, Scopus, Web of Science, Embase, and the Virtual Health Library, up to November 2024. Observational studies reporting clinical manifestations, imaging patterns, and outcomes in patients diagnosed with EVALI according to the Centers for Disease Control and Prevention case definition were included. After full-text assessment, relevant data were extracted. Pooled prevalence estimates for clinical symptoms and radiological findings was calculated using a random-effects model, with Freeman-Tukey double arcsine transformation to stabilize variances. RESULTS: Thirty-eight studies were included in the final analysis, comprising 36 from the United States and 2 from Canada, with patients diagnosed between 2019 and 2022 (n = 13,516). The population consisted predominantly of adolescents and young adults, with male predominance. Most patients reported vaping for more than three months prior to symptom onset (data reported in 10 studies). Constitutional symptoms were present in 87.3% of cases (n = 1878/2555), respiratory symptoms 87.1% (n = 3657/5173), and gastrointestinal manifestations in 77.1% (n = 3164/5193). The most frequent clinical manifestations were shortness of breath (82.7%), dyspnea (81.2%), fever (79.9%), cough (77.4%), and nausea/vomiting (75.0%). Hospitalization was required in 94.4% of cases (n = 386/418), with 35.7% requiring intensive care unit admission (n = 2172/5240). Overall mortality was 0.9% (n = 217/10,635), with minimal variation across studies. The most common imaging features were bilateral pulmonary involvement (98.1%) and ground-glass opacities (94.9%). CONCLUSION: EVALI presents with a variable clinical spectrum, primarily characterized by respiratory and constitutional symptoms. Despite its relatively low-mortality-rate, the high rates of hospitalization and ICU admission underscore the severity of this condition. Early recognition and timely medical intervention are essential to reducing morbidity and mortality, particularly among adolescents and young adults who use e-cigarettes or vaping products.