STUDY OBJECTIVE

To describe recent practice patterns of preoperative tests and to examine their association with 90-day all-cause readmissions and length of stay.

DESIGN

Retrospective cohort study using the New York Statewide Planning and Research Cooperative System (SPARCS).

SETTING

SPARCS from March 1, 2016, to July 1, 2017.

PARTICIPANTS

Adults undergoing Total Hip Replacement (THR) or Total Knee Replacement (TKR) had a preoperative screening outpatient visit within two months before their surgery.

INTERVENTIONS

Electrocardiogram (EKG), chest X-ray, and seven preoperative laboratory tests (RBCs antibody screen, Prothrombin time (PT) and Thromboplastin time, Metabolic Panel, Complete Blood Count (CBC), Methicillin Resistance Staphylococcus Aureus (MRSA) Nasal DNA probe, Urinalysis, Urine culture) were identified.

PRIMARY AND SECONDARY OUTCOME MEASURES

Regression analyses were utilized to determine the association between each preoperative test and two postoperative outcomes (90-day all-cause readmission and length of stay). Regression models adjusted for hospital-level random effects, patient demographics, insurance, hospital TKR, THR surgical volume, and comorbidities. Sensitivity analysis was conducted using the subset of patients with no comorbidities.

RESULTS

Fifty-five thousand ninety-nine patients (60% Female, mean age 66.1+/- 9.8 SD) were included. The most common tests were metabolic panel (74.5%), CBC (66.8%), and RBC antibody screen (58.8%). The least common tests were MRSA Nasal DNA probe (13.0%), EKG (11.7%), urine culture (10.7%), and chest X-ray (7.9%). Carrying out MRSA testing, urine culture, and EKG was associated with a lower likelihood of 90-day all-cause readmissions. The length of hospital stay was not associated with carrying out any preoperative tests. Results were similar in the subset with no comorbidities.

CONCLUSIONS

Wide variation exists in preoperative tests before THR and TKR. We identified three preoperative tests that may play a role in reducing readmissions. Further investigation is needed to evaluate these findings using more granular clinical data.