Reasons for exclusion of articles at stage 1 on the basis of titles and abstracts
| Reason for exclusion at stage 1 | Number of articles (%) |
| Focus on medical or physical environmental factors | 302 (28) |
| Focus on conditions subsequent to development of asthma | 163 (15) |
| Focus on adverse experience occurring in adult life | 94 (9) |
| Does not follow prospective/longitudinal design | 80 (7) |
| Focus on treatment interventions | 192 (18) |
| Focus on adherence | 57 (5) |
| Focus on diseases or conditions other than asthma | 85 (8) |
| Focus on impact of health behaviours on asthma symptoms | 48 (4) |
| Articles retained for further review | 49 (5) |
| Total | 1070 (100) |