TY - JOUR T1 - Understanding the consequences of GP referral thresholds: taking the instrumental approach JO - BMJ Quality & Safety UR - https://eprints.whiterose.ac.uk/id/eprint/195749 PY - 2023/01/27 AU - Lewis J AU - Burton C ED - DO - DOI: 10.1136/bmjqs-2022-015557 PB - BMJ VL - 32 IS - 6 Y2 - 2025/11/17 ER -