BackgroundNHS England has mandated use of the National Early Warning Score (NEWS), more recently NEWS2, in acute settings, and suggested its use in primary care. However, there is reluctance from GPs to adopt NEWS/NEWS2.AimTo assess whether NEWS calculated at the point of GP referral into hospital is associated with outcomes in secondary care.Design and settingAn observational study using routinely collected data from primary and secondary care.MethodNEWS values were prospectively collected for 13 047 GP referrals into acute care between July 2017 and December 2018. NEWS values were examined and multivariate linear and logistic regression used to assess associations with process measures and clinical outcomes.ResultsHigher NEWS values were associated with faster conveyance for patients travelling by ambulance, for example, median 94 minutes (interquartile range [IQR] 69–139) for NEWS ≥7; median 132 minutes, (IQR 84–236) for NEWS = 0 to 2); faster time from hospital arrival to medical review (54 minutes [IQR 25–114] for NEWS ≥7; 78 minutes [IQR 34–158] for NEWS = 0 to 2); as well as increased length of stay (5 days [IQR 2–11] versus 1 day [IQR 0–5]); intensive care unit admissions (2.0% versus 0.5%); sepsis diagnosis (11.7% versus 2.5%); and mortality, for example, 30-day mortality 12.0% versus 4.1% for NEWS ≥7 versus NEWS = 0 to 2, respectively. On average, for patients referred without a NEWS value (NEWS = NR), most clinical outcomes were comparable with patients with NEWS = 3 to 4, but ambulance conveyance time and time to medical review were comparable with patients with NEWS = 0 to 2.ConclusionThis study has demonstrated that higher NEWS values calculated at GP referral into hospital are associated with a faster medical review and poorer clinical outcomes.