Table 4.
Health outcomes of included studies
| Study | Subjects | Outcome | Impact on health outcome | Evidence | Quality |
|---|---|---|---|---|---|
| Farsalinos [17] | 145 | SBP and HR | From 141 to 132 mmHg, p < 0.001 | 1B | Good |
| Alzahrani [20] | 6904 | MI | OR = 1.79; 95% CI 1.20–2.66 | 2C | Poor |
| Farsalinos [17] | 33,028, 26,742 | MI and CHD | OR = 1.35; 95% CI 0.80–2.27 | 2C | Fair |
| Osei [18] | 449,092 | CVD | OR = 1.04; 95% CI 0.63–1.72 | 2C | Poor |
| Parekh | 161,529 | Stroke | OR = 0.69, 95% CI 0.34, 1.42 | 2C | Fair |
| Polosa [16] | 89 | SBP and DBP | 40–130 mmHg; p < 0.001; 86–80 mmHg; p = 0.006 | 3B | Good |
| Bowler [22] | 4596 | COPD respiratory symptoms | p = 0.01 | 2A | Good |
| Polosa [23] | 44 | COPD exacerbations | p = 0.019; p = 0.001 | 2B | Good |
| Lappas [33] | 54 | Impulse oscillometry impedance | p = 0.022 | 2B | Poor |
| Polosa [24] | 48 | COPD exacerbations | Mean 2.3 at baseline to 1.8; p = 0.002 | 2C | Good |
| Miler [35] | 914 | Respiratory infections | 66% (95% CI 62.9–69.0) | 2C | Poor |
| Bhatta [53] | 705,159 | Chronic bronchitis, emphysema, COPD | OR = 1.75, 95% CI 1.25–2.45 | 2C | Poor |
| Cho [30] | 35,904 | Asthma | OR = 2.74; 95% CI 1.30–5.78 | 2C | Poor |
| Choi [31] | 36,085 | Asthma attacks | OR = 1.78, 95% CI 1.20–2.64 | 2C | Poor |
| Kim [32] | 216,056 | Asthma | OR = 1.13; 95% CI 1.01–1.26 | 2C | Poor |
| Osei [25] | 5454 | COPD | OR = 2.94, 95% CI 1.73–4.99 | 2C | Poor |
| Perez [26] | 32,320 | COPD | OR = 1.43, 95% CI 1.12–1.85 | 2C | Poor |
| Schweitzer [34] | 6082 | Asthma | OR = 1.48; 95% CI 1.24–1.78 | 2C | Poor |
| Wills [27] | 8087 | Asthma or COPD | OR = 1.33, 95% CI 1.00–1.77, p < 0.05 | 2C | Fair |
| Xie [28] | 887,182 | COPD | OR = 1.47; 95% CI 1.01, 2.12 | 2C | Fair |
| Sommerfeld [14] | 1 | Dyspnea, cough, and pleuritic chest pain after e-cigarette use | Case study of single EC user developing sensitivity pneumonitis | 4 | Fair |
| Khan [13] | 1 | Organising pneumonia | Single case study of organizing pneumonia, exclusion of other drug use and comorbidities not mentioned | 4 | Poor |
| Carter [12] | 1 | Vesicular Bronchial Injury | Case study showed vesicular bronchial injury in an EC user. Patient had CVD and other comorbidities and was a former smoker | 4 | Poor |
| Franco [36] | 65 | Oral mucosa pre-cancerous cells | p = 0.001; p = 0.004 | 2C | Fair |
| Nguyen [15] | 2 | Oral carcinoma | Two cases of oral carcinoma associated with 13-year use of EC. Description of other risks not detailed | 4 | Fair |
| Akinkugbe [43] | 13,650 | Dental problems | OR = 1.11; 95% CI 0.79–1.55 | 2C | Poor |
| Bandiera [37] | 5445 | Depressive symptoms | β = 0.05; p < 0.01 | 2B | Good |
| Lechner [38] | 347 | Depressive symptoms | b = 1.272, SE = 0.513, p = 0.01 | 2B | Good |
| Dahal [39] | 52,956 | Depressive symptoms | OR = 2.46; 95% CI 1.82–3.33 | 2C | Poor |
| Chadi [41] | 26,821 | Depressive symptoms, suicidal ideation | OR = 1.23; 95% CI 1.03–1.47 | 2C | Poor |
| Grant [54] | 3572 | Mental health issues | p = 0.052 | 2C | Fair |
| King [40] | 2370 | Depression | OR = 1.04; 95% CI 1.01–1.08 | 2C | Fair |
| Pham [42] | 53,050 | Mood disorders | OR = 1.9; 95% CI 1.2–3.0 | 2C | Poor |
| Lanza [44] | 452 | BMI | β = 1.48, OR = 4.40, p < 0.05 | 2C | Poor |
| Miler [45] | 1 | Exacerbations of tonsillitis | After 8 months of vaping, the patient reported absence of exacerbations of tonsillitis, and marked improvement in Tonsillitis. The study did not mention any other comorbidities or exhaustively account for all confounders | 4 | Fair |
| Maridet [46] | 1 | Clinically-determined erythematous, scaly dermatitis | Patient diagnosed with nickel contact dermatitis associated with the use of an EC | 4 | Good |