Preoperative test requests for elective surgeries of different complexity: Appropriateness and interhospital variability

Abstract

Background: Numerous studies have questioned the usefulness of routine preoperative tests, and several guidelines have published recommendations aimed at reducing unnecessary preoperative testing.

Study objectives: To analyze the appropriateness of preoperative test requests and interhospital variability in criteria for requesting preoperative tests.

Design: Cross-sectional retrospective multicenter observational study.

Setting: Nine Spanish National Health System hospitals.

Patients: Patients over 18 years of age undergoing elective cataract surgery, inguinal hernia, laparoscopic cholecystectomy, colon surgery or primary knee replacement, in any department of the participating hospitals during 5 working days in June 2022 (n = 1522).

Exposure: Hospitals where patients underwent surgery.

Measurements: Appropriateness of requested preoperative tests according to hospital protocols and NICE guidelines analyzed with random-intercept multilevel models considering hospital-level and patient-level variables. Hospital protocol score to determine disagreement with the NICE guidelines.

Main results: Preoperative test request inappropriateness was 12.03 % according to hospital protocols and 72.99 % according to the NICE guidelines. Inappropriateness was mostly due to excessive requests and differed by hospital and surgery type. Independent factors determining inappropriateness at the hospital-level were center complexity and availability of computerized preoperative request templates; at the patient-level were age, ASA grades and surgical complexity. Protocol criteria for requesting preoperative tests varied notably between hospitals, and most protocols showed low agreement with NICE recommendations, especially in terms of over-requested preoperative tests.

Conclusions: Inappropriateness of preoperative test requests was high according to hospital protocols and especially high according to the NICE guidelines. Appropriateness was determined by patient characteristics, surgical complexity, and institutional factors. Interhospital variability in inappropriateness was explained by differing criteria for preoperative test requests.

Keywords: Appropriateness; Interhospital variability; Preoperative tests.