Characteristics of the studies in the review
| Characteristics | Sample (13 independent data sets) | Percentage of total k (%) |
| Age (years) | ||
| 0–11 | – | – |
| 12–35 | 3 | 22 |
| 36–50 | 8 | 62 |
| 51–65 | – | – |
| 65+ | 1 | 8 |
| Not specified | 1 | 8 |
| Gender | ||
| Male only | – | – |
| Female only | – | – |
| Mixed | 13 | 100 |
| PA levels at baseline | ||
| Meeting guidelines | – | – |
| Not meeting guidelines | 6 | 46 |
| Mixed | – | – |
| Unreported | 7 | 54 |
| Population | ||
| Community | 10 | 77 |
| Clinical | 2 | 15 |
| Assisted-living residents | 1 | 8 |
| Geographical location | ||
| USA | 10 | 77 |
| UK | 1 | 8 |
| Canada | 2 | 15 |
| Study design | ||
| Randomised trial | 8 | 62 |
| Quasi-experimental | 3 | 23 |
| Single group | 2 | 15 |
| Quality rating | ||
| Moderate | 8 | 62 |
| Low | 5 | 38 |
| Theory | ||
| No framework explicitly mentioned | 7 | 54 |
| Multi-process action control | 1 | 8 |
| Social–cognitive theory | 4 | 31 |
| Health promotion model | 1 | 8 |
| PA measurement | ||
| Objective | 9 | 69 |
| Validated self-report | 3 | 23 |
| Study created self-report | 1 | 8 |
| Setting of the intervention | ||
| Supervised clinical setting (hospital, assisted-living facilities) | 3 | 23 |
| Community/home | 10 | 77 |
| Medium | ||
| Group face-to-face | 3 | 23 |
| Emails | 4 | 31 |
| Individual face-to-face | 4 | 31 |
| Internet/mail | 2 | 15 |
PA, physical activity.