Additional file 1 of Association between electronic cigarette use and tobacco cigarette smoking initiation in adolescents: a systematic review and meta-analysis

Additional file 1: We present all additional information in one excel file (supplementary excel file) and within the file each tab is a single appendix. Appendix 1. (or Table 1) presents the Medline literature search strategy. Appendix 2. presents the study PRISMA flow chart. Appendix 3. presents the quality assessment tool and results. Appendix 4. presents characteristics of included studies. Appendix 5. presents primary research AOR for ever e-cigarette and cigarette use among adolescents in the selected longitudinal cohort studies. Appendix 6. presents primary studies ever use of e-cigarettes and cigarettes among adolescents in the selected longitudinal cohort studies using statistical measures such as adjusted relative risk, estimates, or standardised coefficient. Appendix 7. presents AORs for different frequencies of e-cigarette and cigarette use among adolescents in the selected longitudinal cohort studies. Appendix 8. presents adjusted relative risk for different frequencies of e-cigarette and cigarette use. Appendix 9. presents the feasibility assessment for meta-analysis and Appendix 10. presents the results of the meta-analysis, sensitivity analysis, and subgroup analysis.