What is the clinical evidence from this study?

Study design: Cohort. Population: Surgery (n=12905737). Intervention: High-risk surgical group vs. Low-risk surgical group. Primary outcome: Death within 90 days after the index surgery (RR 117.15, 95% CI 115.18-119.14).

What does this research mean for the field?

High-risk surgical patients experience a 90-day mortality rate of 13.9%, representing a substantially higher risk of death compared to low-risk patients, and account for a disproportionate share of postoperative healthcare resources. Novelty: ClaimNovelty.INCREMENTAL. Consensus alignment: ConsensusAlignment.NEUTRAL.

February 24, 2026Open Access

Long-term outcomes for patients at high risk of death after surgery in the UK: a retrospective cohort study

Key Result

High-risk surgical patients experienced a 90-day mortality rate of 13.9%, representing a substantially higher risk of death compared to low-risk patients (RR 117.15; 95% CI 115.18-119.14).

Study Design

Type

Cohort (n=12,905,737)

Multicenter

Yes

Structured PICO

What are the long-term outcomes and resource needs of high-risk surgical patients compared to low-risk patients?

Population

12,905,737 adults (aged ≥18 years) undergoing elective or emergency, in-patient or day-case, non-obstetric surgery between Jan 1, 2015, and Dec 31, 2019 (Dec 31, 2018, in Wales) in the UK. Mean age 57.5, 53.2% women.

Intervention

High-risk surgical group (patients accounting for the first 80% of deaths based on a logistic regression model)

Comparator

Low-risk surgical group (patients accounting for the final 5% of deaths)

Outcome

Death within 90 days after the index surgeryhard clinical

High-risk surgical patients in the UK experience poor outcomes and consume a disproportionately large share of healthcare resources, highlighting significant policy and delivery challenges.

Main Result

Effect estimate: RR 117.15 (95% CI 115.18-119.14)

Abstract

BACKGROUND: More than 5 million surgical procedures are performed every year in the UK, but little is known about individuals at high surgical risk who account for most deaths after surgery. We aimed to describe the size, demographics, and long-term outcomes of high-risk surgical patients in the UK. METHODS: In this retrospective, observational cohort study, we analysed routine National Health Service (NHS) data from England (hospital episode statistics, and admitted patient care), Scotland (Scottish Morbidity Records), and Wales (Patient Episode Database for Wales). We derived death data from linkage to Office for National Statistics (England 95% CI). FINDINGS: We included 12 905 737 patients (mean age 57·5 SD 19·2 years; 8 584 593 53·2% women, 7 552 101 46·8% men; 12 086 325 74·9% White patients) who experienced 16 136 694 surgical spells. There were 262 500 (1·6%) deaths within 90 days, and 644 596 (4·0%) deaths within 1 year. The median length of stay was 0 days (IQR 0-1), and there were 1 506 299 (9·4%) emergency readmissions within 90 days after surgery. We identified 1 481 357 (9·2%) patient spells in the high-risk group, who had experienced 206 257 (13·9%) deaths within 90 days (RR vs low 117·15 115·18-119·14), a median length of stay of 10 days (IQR 3-21), 426 496 (30·9%) emergency readmissions (RR vs low 5·67 5·65-5·69), and 402 033 (27·1%) deaths within 1 year (RR vs low 38·89 38·61-39·17). As a proportion of all outcomes in the cohort, high-risk patients accounted for 53·8% of all hospital bed-days used after surgery (21 206 482 of 39 441 408), 28·3% of emergency readmissions (426 496 of 1 506 299), and 62·4% of 1-year deaths (402 033 of 644 596). In England, 94·9% (95% CI 94·8-94·9) of patients in the low-risk group survived by 5 years, compared with 75·1% (75·0-75·2) of patients in the moderate-risk group, and 40·3% (40·1-40·4) of patients in the high-risk group. INTERPRETATION: Data from 2015-19 suggest that around 300 000 high-risk patients undergo surgery each year in the NHS. This group have poor outcomes and very high health-care resource needs, which presents important health policy and delivery challenges in the UK. FUNDING: National Institute for Health and Care Research (NIHR).