Characteristics of e-cigarette portfolio, 2009–2015 (n=81)
| Funding source FDA CTP NIH | n 61 20 | % 75 25 |
| Parent grant mechanism | ||
| P (P50, P30) | 25 | 31 |
| R (R03, R21, R01, R15) | 47 | 58 |
| U (U01) | 2 | 2 |
| K (K01, K07, K99) | 4 | 5 |
| F (F31) | 3 | 4 |
| Parent PI terminal degree discipline | ||
| Clinical and experimental psychology | 17 | 21 |
| Medicine | 8 | 10 |
| Public health/epidemiology | 8 | 10 |
| Other | 48 | 59 |
| Project start | ||
| 2011 | 1 | 1 |
| 2012 | 8 | 10 |
| 2013 | 28 | 34 |
| 2014 | 24 | 30 |
| 2015 | 20 | 25 |
| Research domain* | ||
| Chemistry and Engineering | 21 | 26 |
| Knowledge, Attitudes, and Behaviors | 42 | 52 |
| Addiction | 17 | 21 |
| Toxicity and Carcinogenicity | 23 | 28 |
| Health Consequences | 20 | 25 |
| Communications | 15 | 18 |
| Tobacco Product Marketing | 17 | 21 |
| Economics and Policy | 7 | 9 |
| Primary population under study* | ||
| Adults (18+) | 46 | 57 |
| Young adults (18–29) | 17 | 21 |
| Adolescents (12–17) | 6 | 7 |
| Dual/polyuser | 10 | 12 |
| ENDS user | 26 | 32 |
| Cigarette smoker | 41 | 51 |
| Vulnerable population (other than age) | 14 | 17 |
| Non-human subject/animal model | 8 | 10 |
| Other | ||
| Type of ENDS* | ||
| Not specified | 52 | 64 |
| Cig-alike and cigarette-shaped | 16 | 20 |
| Tank systems | 9 | 11 |
| Advanced customisable/modifiable tank systems | 4 | 5 |
| Liquid solution for ENDS (e-liquid) | 12 | 15 |
| HAVE primary focus | ||
| Host | 59 | 73 |
| Agent | 17 | 21 |
| Vector | 5 | 6 |
| Environment | 0 | 0 |
| Includes any HAVE measure | ||
| Host | 75 | 93 |
| Agent | 42 | 52 |
| Vector | 25 | 31 |
| Environment | 23 | 28 |
*Multiple options could be selected.
ENDS, electronic nicotine delivery system; FDA CTP, Food and Drug Administration’s Center for Tobacco Products; NIH, National Institutes of Health; PI, principal investigator.