RT Journal Article SR Electronic T1 How to use directed acyclic graphs: guide for clinical researchers JF BMJ JO BMJ FD British Medical Journal Publishing Group SP e078226 DO 10.1136/bmj-2023-078226 VO 388 A1 Feeney, Timothy A1 Hartwig, Fernando Pires A1 Davies, Neil M YR 2025 UL https://www.bmj.com/content/388/bmj-2023-078226.abstract AB