Identifying HCV-treated and HCV-untreated patients

Patients treated with DAA-based therapies before TSA were classified as “treated.” Patients treated with older therapies, including ribavirin and interferon, were excluded from the analysis due to lower overall cure rates (around 50%) and higher complication rates relative to DAA-based therapies, which have cure rates over 95%.4^,17 An undetectable HCV viral load was not used to confirm successful treatment.

ICD-9 and ICD-10 codes were used to identify preoperative comorbidities and to calculate the Charlson Comorbidity Index (CCI) for each patient.24 A comorbid condition was considered present if it was recorded in the patient’s record during one inpatient or 2 outpatient encounters between January 1, 2014 and the date of surgery.