%0 Journal Article %A Jen Lewis %A Christopher Burton %T Understanding the consequences of GP referral thresholds: taking the instrumental approach %D 2023 %R 10.1136/bmjqs-2022-015557 %J BMJ Quality & Safety %P 309-311 %V 32 %N 6 %U https://qualitysafety.bmj.com/content/qhc/32/6/309.full.pdf