Data-based studies by level of the Ecological Model of Health Promotion and year*
| Ecological model level | 2000–2004** | 2005–2009 | 2010–2014 |
|---|---|---|---|
| Intrapersonal | N=6 | N=25 | N=47 |
| Interpersonal | N=6 | N=21 | N=66 |
| Institutional/organisational | N=2 | N=8 | |
| Community | N=3 | N=3 | N=10 |
| Policy | N=12 |
*The total N is greater than 131 as several articles include more than one level. The level of each of the data-based articles is listed in the reference list. References30–67 were coded as part of the methodological analysis but not referenced directly in the text. **Although this review abstracted articles starting in 1990, no articles exploring WTS determinants were found prior to the year 2000.