Change in healthcare utilisation after surgical treatment: observational study of routinely collected patient data from primary and secondary care.

<bold>Background: </bold>Most patients fully recover after surgery. However, high-risk patients may experience an increased burden of medical disease.<bold>Methods: </bold>We performed a prospectively planned analysis of linked routine primary and secondary care data describing adult patients undergoing non-obstetric surgery at four hospitals in East London between January 2012 and January 2017. We categorised patients by 90-day mortality risk using logistic regression modelling. We calculated healthcare contact days per patient year during the 2 yr before and after surgery, and express change using rate ratios (RaR) with 95% confidence intervals.<bold>Results: </bold>We included 70 021 patients, aged (mean [standard deviation, sd]) 49.8 (19) yr, with 1238 deaths within 2 yr after surgery (1.8%). Most procedures were elective (51 693, 74.0%), and 20 441 patients (29.1%) were in the most deprived national quintile for social deprivation. Elective patients had 12.7 healthcare contact days per patient year before surgery, increasing to 15.5 days in the 2 yr after surgery (RaR, 1.22 [1.21-1.22]), and those at high-risk of 90-day mortality (11% of population accounting for 80% of all deaths) had the largest increase (37.0 days per patient year before vs 60.8 days after surgery; RaR, 1.64 [1.63-1.65]). Emergency patients had greater increases in healthcare burden (13.8 days per patient year before vs 24.8 days after surgery; RaR, 1.8 [1.8-1.8]), particularly in high-risk patients (28% of patients accounting for 80% of all deaths by day 90), with 21.6 days per patient year before vs 49.2 days after surgery; RaR, 2.28 [2.26-2.29].<bold>Discussion: </bold>High-risk patients who survive the immediate perioperative period experience large and persistent increases in healthcare utilisation in the years after surgery. The full implications of this require further study. [ABSTRACT FROM AUTHOR]