The study population consisted of two cohorts. Patients who underwent hepatectomy (ICD-9-CM procedure code: 50.2, 50.22, 50.3 and 50.4) between 2000 and 2012 were identified as the surgery cohort. The index date was defined as the earliest date that patients underwent hepatectomy. Patients without any record of hepatectomy during the same period of time were defined as the control cohort. Patients younger than 20 years of age and those diagnosed with coagulation defects (ICD-9-CM: 286.4) or had a pre-existing bleeding episode before the index date. The primary outcome of this study was an incident diagnosis of major bleeding, consisting of 3 categories: intracranial bleeding (ICD-9-CM; 430, 431, 432.0, 432.1, 432.9, 852.0, 852.2, 852.4, 853.0), gastrointestinal (GI) bleeding (ICD-9-CM; 456.0, 456.20, 530.7, 531, 531.2, 531.4, 531.6, 532, 532.2, 532.4, 532.6, 533, 533.2, 533.4, 533.6, 534, 534.2, 534.4, 534.6, 535.01, 535.11, 535.21, 535.31, 535.41, 535.51, 535.61, 535.71, 537.83, 537.84, 562.02, 562.03, 562.12, 562.13, 569.3, 569.85, 578) and other sites bleeding [ICD-9-CM; 336.1, 363.6, 372.72, 376.32, 377.42, 379.23 (eye); 593.81, 866.01, 866.02, 866.11, 866.12 (kidney); 719.1 (joint); 729.92 (soft tissue); 423.0 (heart); 772.5 (adrenal gland), 626.8, 626.9 (uterine)].~Demographic characteristics evaluated in this study included gender, age, comorbidities and prescribed medications. The comorbidities included hypertension (ICD-9-CM; 401-405, A260 and A269), hyperlipidemia (ICD-9-CM: 272), chronic liver disease (ICD-9-CM: 571.4, 571.5), hepatitis C virus (HCV) infection (ICD-9-CM: 070.41, 070.44, 070.51, 070.54, and V02.62), malignant neoplasm of liver and intrahepatic bile ducts (ICD-9-CM: 155), cirrhosis (ICD-9-CM: 571, A347), chronic kidney disease (ICD-9-CM: 580-589, A350), alcohol-related disease (ICD-9-CM: 291, 303, 305.0, 357.5, 425.5, 535.3, 571.0-571.3, 980.0, E947.3), biliary stone disease (ICD-9-CM: 574), and diabetes mellitus (ICD-9-CM: 250). The investigators also searched the clinical records for the use of anticoagulants, antiplatelets, thrombolytic agents, non-steroidal anti-inflammatory drugs (NSAIDs), serotonin-norepinephrine reuptake inhibitors (SNRIs) and selective serotonin reuptake inhibitors (SSRIs) prescribed before the index date. The investigators applied a 4:1 propensity-score matched analysis to reduce selection bias between cases and controls.
This study examined long-term incidence rates of major bleeding associated with hepatectomy. The investigators used data from Taiwan's National Health Insurance Research Database. Patients who underwent hepatectomy between 2000 and 2012 were identified by International Classification of Diseases, Ninth Revision, Clinical Modification codes. Variables including gender, age, comorbidities, and prescribed medications were matched between cases and controls. A total of 1,053 patients with hepatectomy and 4,212 matched non-hepatectomy subjects were included in this study.