| Variable | Year | Supplement |
|---|---|---|
| ECIGEV | 2014 | Sample adult questionnaire |
| ECIGEV1 | 2015 | Sample adult cancer |
| ECIGEV2 | 2018 | Sample adult questionnaire |
| ECIGEV2 | 2017 | Sample adult questionnaire |
| ECIGEV2 | 2016 | Sample adult questionnaire |
| ECIGEV_A | 2020 | Sample adult questionnaire |
| ECIGEV_A | 2019 | Sample adult questionnaire |