Reasons for exclusion of articles at stage 1 on the basis of titles and abstracts

Reason for exclusion at stage 1Number of articles (%)
Focus on medical or physical environmental factors302 (28)
Focus on conditions subsequent to development of asthma163 (15)
Focus on adverse experience occurring in adult life94 (9)
Does not follow prospective/longitudinal design80 (7)
Focus on treatment interventions192 (18)
Focus on adherence57 (5)
Focus on diseases or conditions other than asthma85 (8)
Focus on impact of health behaviours on asthma symptoms48 (4)
Articles retained for further review49 (5)
Total1070 (100)