Differences in Postoperative Disposition by Kidney Disease Severity: A Population-Based Cohort Study.

Abstract

Rationale & objective: People with advanced kidney disease undergo more non-cardiac operations compared to the general population, with a higher risk of perioperative cardiac events and death. However, little is known about the associations between severity of preoperative kidney dysfunction with postoperative length of hospitalization and discharge disposition; these were the focus of this study.

Study design: Population-based retrospective cohort.

Setting & participants: Adults from Alberta, Canada undergoing inpatient major noncardiac surgery between April 2005 and February 2019.

Exposure: Categorical preoperative outpatient estimated glomerular filtration rate (eGFR) or kidney failure status.

Outcomes: Length of stay (LOS), days alive at home after surgery within 30 and 90 days, and discharge disposition location.

Analytical approach: Associations were estimated with unadjusted and adjusted generalized estimating equation models.

Results: 927,560 inpatient surgeries in 666,770 people (55.9% female, median age 57.4 years) were identified. People receiving dialysis had the longest LOS (11 days [95% CI 6, 29), 2 times greater than that among people with normal kidney function (adjusted incidence rate ratio [IRR] 2.21 [95% CI 2.10, 2.32]). This group also had the fewest days alive at home within the first 30 days after surgery, with an IRR of 0.69 (95% CI 0.67, 0.70) compared to people with normal eGFR. The majority of people (82.8%) were discharged home without nursing support after surgery, though people receiving dialysis were discharged to a facility with 24-hour nursing care nearly 4 times more often. There were graded increases in risks of these outcomes with lower levels of kidney function.

Limitations: Many people did not have preoperative kidney function assessed, reflecting standard clinical practice in the general population.

Conclusions: After major surgery, people with kidney disease spend more time recovering in hospital and have less independence from post-discharge nursing supports than otherwise similar patients who have normal or near normal kidney function. These differences were more pronounced for those with the most severe stages of kidney disease.