Searching for Evidence on Adolescent Vaping and Asthma Exacerbations
Your primary care clinic serves 1,100 adolescents; 22% have persistent asthma, and a recent waiting-room survey found 18% report past-30-day e-cigarette use. A parent asks whether vaping worsens her son’s asthma. You have 30 minutes before clinic and access to PubMed, CINAHL, and the Cochrane Library. A quick search for “adolescent AND asthma AND e-cigarette OR vaping” yields 1,240 citations. After title/abstract screening you retain 12: one systematic review of 14 observational studies, three cohort studies, and one small RCT of a cessation intervention. One cohort reports an adjusted OR of 1.6 (95% CI 1.2–2.1) for exacerbation with daily vaping; another finds no association after adjusting for combustible cigarette use. A colleague says, “If there’s no RCT, we can’t answer the question.” The clinic medical director wants a one-page summary for next week’s staff meeting.
1. Write the PICO question and a reproducible search strategy. Include databases, key terms/MeSH, Boolean logic, limits, and inclusion/exclusion criteria.
Read the worked answer
PICO: In adolescents aged 12–18 with persistent asthma (P), is current e-cigarette or vaping use (I), compared with no e-cigarette use (C), associated with increased asthma exacerbations, rescue-inhaler use, or emergency visits (O)? A reproducible PubMed strategy would combine MeSH and free text: (adolescent OR teen OR youth) AND (asthma OR reactive airway disease) AND (electronic cigarette OR e-cigarette OR vaping OR vape OR JUUL OR ENDS). I would search PubMed, CINAHL using CINAHL Subject Headings, and Cochrane. Limits: English, 2015–present, humans; no design filter initially because harms questions require observational studies. Inclusion: adolescents, asthma diagnosis, e-cigarette exposure, exacerbation or control outcome. Exclusion: adults only, case reports, no asthma outcome. I would also hand-search reference lists of the systematic review and search gray literature from public health agencies. Document the date, databases, full strings, number retrieved, and reasons for exclusion so the search is reproducible.
2. How would you appraise and synthesize the available evidence, and how would you respond to the colleague who demands an RCT?
Read the worked answer
The systematic review is the best starting point because it synthesizes 14 observational studies and should be appraised with AMSTAR-2 for search quality, risk-of-bias assessment, heterogeneity, and publication bias. The cohort with adjusted OR 1.6 (95% CI 1.2–2.1) supports an association, but the null cohort after adjusting for combustible cigarettes shows confounding is a major threat; dual use and asthma severity may drive both vaping and exacerbations. I would not demand an RCT for a harms question: randomizing adolescents to vaping would be unethical, and the best available design is a well-adjusted prospective cohort or causal-inference study. I would grade certainty as low to moderate, present the range of effects, note that association is not causation, and recommend asking about vaping at every asthma visit, offering cessation counseling, and avoiding a clinic-wide ban on evidence-based tobacco-cessation messages. The one-page summary should state what is known, what is uncertain, and what to do now.