Table 1.
Longitudinal Study Characteristics and Outcomes
| Author year | Total N | Time | CO for inclusion | CPD at baseline | % Change from baseline | Risk of bias | ||||
|---|---|---|---|---|---|---|---|---|---|---|
| Follow-up group N | NNAL | NNN | NAB | NAT< | ||||||
| RCT | RoB2 | |||||||||
| Jay 202040* | 90 | 5 days | CO ≥12 ppm | CPD M = 16.2 SD = 3.6 | Vaping n = 60 Nonuse n = 11 |
↓68% ↓67% |
↓61% ↓99% |
Some concerns | ||
| Round 201939* | 158 | 5 days | CPD M = 14.4 | Vaping+n = 38 Vaping+n = 40 |
↓59% ↓55% |
↓87% ↓92% |
Some concerns | |||
| Cohen 202137* | 295 | 6 days | CO >10 ppm | CPD M = 18 SD = 5.2 | Vaping n = 188 Nonuse n = 23 |
↓66% ↓64% |
↓93% ↓97% |
↓89% ↓87% |
↓99% ↓98% |
Some concerns |
| McEwan 202142* | 148 | 7 days | CO >10 ppm | CPD M = 20.1 SD = 4.83 | Vaping n = 28 Nonuse n = 29 |
↓65% ↓68% |
↓77% ↓80% |
Some concerns | ||
| Morris 202236* | 80 | 14 days | CO >10ppm | CPD > 10 | Vaping+n = 14 Vaping+n = 11 |
↓73% ↓79% |
↓92% ↓89% |
Some concerns | ||
| Pulvers 202041 | 186 | 6 weeks | CO >5ppm | CPD M = 12.1 SD = 7.2 | Vaping n = 32 | ↓95% | Some concerns | |||
| Hatsukami 202038 | 264 | 8 weeks | CO ≥8 ppm | CPD > 5 | Vaping n = 57 | ↓53% | Some concerns | |||
| Edmiston 202235* | 150 | 24 weeks | CPD M = 17.6 SD = 5.0 | Vaping+n = 48 Vaping+n = 50 |
↓84% ↓73% |
Some concerns | ||||
| Non-randomized intervention study | ROBINS-I | |||||||||
| Goniewicz 201743 | 20 | 2 weeks | CPD M = 16 SD = 9 | Vaping n = 9 | ↓72% | Moderate | ||||
| Pulvers 201844 | 40 | 4 weeks | CPD M = 8.8 SD = 6.53 | Vaping n = 6 | ↓97% | Moderate | ||||
| Observational longitudinal | Newcastle-Ottawa | |||||||||
| Anic 202246 | 2475 | 12 months | CPD M = 11 CPD M = 5 |
Vaping n = 28 Nonuse n = 188 |
↓93% ↓85% |
↓83% ↓44% |
↓89% ↓65% |
↓94% ↓75% |
7/9 | |
| Dai 202245 | 3211 | 12 months | CPD M = 16.7 | Vaping n = 32 Nonuse n = 246 |
↓92% ↓84% |
↓82% ↓44% |
↓90% ↓63% |
↓96% ↓74% |
7/9 | |
+ Results were separated by vape flavor, see Supplementary Table S6 for details.
*Denotes studies funded by the tobacco industry.
CPD = cigarettes per day, CO = carbon monoxide, M = mean, SD = standardized deviation, ↓ indicates % decrease between baseline and follow-up.
Unless otherwise stated, results indicate urinary levels.