Cancelled operations: a 7-day cohort study of planned adult inpatient surgery in 245 UK National Health Service hospitals.

Cancellation of planned surgery impacts substantially on patients and health systems. This study describes the incidence and reasons for cancellation of inpatient surgery in the UK NHS.We conducted a prospective observational cohort study over 7 consecutive days in March 2017 in 245 NHS hospitals. Occurrences and reasons for previous surgical cancellations were recorded. Using multilevel logistic regression, we identified patient- and hospital-level factors associated with cancellation due to inadequate bed capacity.We analysed data from 14 936 patients undergoing planned surgery. A total of 1499 patients (10.0%) reported previous cancellation for the same procedure; contemporaneous hospital census data indicated that 13.9% patients attending inpatient operations were cancelled on the day of surgery. Non-clinical reasons, predominantly inadequate bed capacity, accounted for a large proportion of previous cancellations. Independent risk factors for cancellation due to inadequate bed capacity included requirement for postoperative critical care [odds ratio (OR)=2.92; 95% confidence interval (CI), 2.12-4.02; P<0.001] and the presence of an emergency department in the treating hospital (OR=4.18; 95% CI, 2.22-7.89; P<0.001). Patients undergoing cancer surgery (OR=0.32; 95% CI, 0.22-0.46; P<0.001), obstetric procedures (OR=0.17; 95% CI, 0.08-0.32; P<0.001), and expedited surgery (OR=0.39; 95% CI, 0.27-0.56; P<0.001) were less likely to be cancelled.A significant proportion of patients presenting for surgery have experienced a previous cancellation for the same procedure. Cancer surgery is relatively protected, but bed capacity, including postoperative critical care requirements, are significant risk factors for previous cancellations.