Comparative Analysis of Injectable Anticoagulants for Thromboprophylaxis Post Cancer-related Surgery

Study Overview
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Brief Summary
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Venous thromboembolism (VTE), including deep vein thrombosis (DVT) and pulmonary embolism (PE), is a common post-operative complication. The effectiveness of fondaparinux compared with other injectable anticoagulants in VTE following major orthopedic and abdominal surgery has been evaluated in database studies; however, the effectiveness of injectable anticoagulant medications following cancer-related surgeries in the practice setting has not been as well documented. The objective of this study is to analyze patient records from a national hospital database and compare the outcomes and costs between four types of injectable anticoagulant medications that were prescribed for the prevention of VTE following cancer-related surgery. This analysis will assess and quantify the outcomes, resource utilization, and cost of care for patients receiving fondaparinux, enoxaparin, dalteparin or unfractionated heparin. The outcomes of interest include the occurence of VTE, rates of major bleeds, medical resource utilization, and total costs (medical plus pharmacy). The source of data for this study is the Premier Perspective Database™. This hospital claims database links de-identified inpatient medical, pharmacy, and billing data from more than 500 hospitals. This study is a retrospective cohort study that uses propensity score matching to adjust for the differences between the numbers of patients treated with each medication.

Official Title
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Comparative Analysis of Injectable Anticoagulants for Thromboprophylaxis Post Cancer-related Surgery

Conditions
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Thrombosis, Venous

Intervention / Treatment
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* Drug: dalteparin
* Drug: enoxaparin
* Drug: fondaparinux
* Drug: unfractionated heparin


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: age 18 and older at least one record of a primary inpatient discharge diagnosis of cancer (index hospitalization) a procedure code for a cancer-related surgery during the index hospitalization a code for an anticoagulant treatment (dalteparin, enoxaparin, fondaparinux or unfractionated heparin (UFH)) as thromboprophylaxis therapy during the day prior to or two days after cancer-related surgery during the index hospitalization (this is the INDEX EVENT) Exclusion Criteria: a record that the patient received more than one injectable anticoagulant on Day 1 of anticoagulant therapy a record that the patient received anticoagulant therapy prior to index anticoagulant a primary diagnosis code of DVT, PE, or major bleed evidence of an outpatient emergency department or hospital outpatient clinic visit that included a diagnosis code for DVT or PE during the 6 months prior to the index hospitalization patient records for patients transferred from another facility outside Premier system on index hospitalization

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Cancer-related surgery patient records<br>Healthcare claims records from patients aged 18 years or older with at least one primary inpatient discharge diagnosis of cancer and a cancer-related surgery during the hospitalization | Drug: dalteparin<br>* An injectable anticoagulant medication for the prevention of VTE related to cancer surgery. Patients received dalteparin during one day prior to or two days after cancer-related surgery during the hospitalization.<br>* Other names: Fragmin® is a registered trademark of Pfizer Health AB;Drug: enoxaparin<br>* An injectable anticoagulant medication for the prevention of VTE related to cancer surgery. Patients received enoxaparin during one day prior to or two days after cancer-related surgery during the hospitalization.<br>* Other names: Lovenox® is a registered trademark of Sanofi-Aventis;Drug: fondaparinux<br>* An injectable anticoagulant medication for the prevention of VTE related to cancer surgery. Patients received fondaparinux during one day prior to or two days after cancer-related surgery during the hospitalization.<br>* Other names: Arixtra® is a registered trademark of GlaxoSmithKline;Drug: unfractionated heparin<br>* An injectable anticoagulant medication for the prevention of VTE related to cancer surgery. Patients unfractionated heparin received during one day prior to or two days after cancer-related surgery during the hospitalization.<br>* Other names: heparin/ns misc;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Rate of occurence of venous thromboembolism (VTE) during index hospitalization | VTE events were identified by International Classification of Disease-9 (ICD-9) codes for deep vein thrombosis (451.xx. 453.xx) and pulmonary embolism (415.xx) during the index hospitalization. Results will be calculated, reported as unadjusted, and adjusted to control for the effect of covariates on outcomes | Data will be collected over a 5 year and 8 month period with this endpoint evaluated from the date of hospital admission to the date of hospital discharge. | 
| Rate of occurence of major bleeding events during hospitalization | Major bleeding events were identified according to ICD-9 codes for major bleed (568.81, 430.xx, 431.xx, 432.xx, or 998.11) or other bleeding accompanied by more than 2 units of blood transfused (246.3, 286.5, 287.3, 287.4, 287.5, 287.8, 287.9, 459.0, 530.82, 569.3, 578.x, 596.7, 599.7, 719.1, 784.7, 784.8, 786.3, 958.2, or 997.02) as recorded in the billing file during the index hospitalization plus 1 month post discharge. Results will be calculated, reported as unadjusted, and adjusted to control for the effect of covariates on outcomes. | Data will be collected over a 5 year and 8 month period with this endpoint evaluated from the date of hospital admission to the date of hospital discharge. | 
| Rate of Hospital readmission rates | Readmission rates were defined as a subsequent hospitalization for major bleeding or VTE that occurred within the follow-up period (discharge month plus 1 month). | Data will be collected over a 5 year and 8 month period with this endpoint evaluated at one month following the date of hospital discharge | 
| Mean length of hospital stay in days | Length of hospital stay was obtained from the discharge record and was defined as the number of days from patient admission to the hospital for cancer-related surgery until discharge from the hospital. | Data will be collected over a 5 year and 8 month period with this endpoint evaluated from the date of hospital admission to the date of hospital discharge. | 
| Total cost of care for index hospitalization in United States (US) dollars | The mean total costs (medical plus pharmacy costs) from patient records in each antithrombotic cohort from the index hospitalization. Results will be calculated, reported as unadjusted, and adjusted to control for the effect of covariates on outcomes. | Data will be collected over a 5 year and 8 month period with this endpoint evaluated from the date of hospital admission to the date of hospital discharge. | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Rate of occurence of VTE events during hospitalization plus 1 month post discharge. | VTE events were identified according to ICD-9 codes for DVT and PE during the index hospitalization plus 1 month post discharge. Results will be calculated, reported as unadjusted, and adjusted to control for the effect of covariates on outcomes. | Data will be collected over a 5 year and 8 month period with this endpoint evaluated from the date of admission for the index hospitalization to the end of the 1-month post-discharge follow-up period | 
| Rate of occurence of major bleeding events during hospitalization plus 1 month post discharge | Major bleeding events were identified according to ICD-9 codes for hemoperitoneum bleed, intracranial hemorrhage/hemorrhagic stroke, hemorrhage complicating a procedure, or other bleeding accompanied by more than 2 units of blood transfused as recorded in the billing file during the index hospitalization plus 1 month post discharge. Results will be calculated, reported as unadjusted, and adjusted to control for the effect of covariates on outcomes. | Data will be collected over a 5 year and 8 month period with this endpoint evaluated from the date of admission for the index hospitalization to the end of the 1-month post-discharge follow-up period | 
| Total cost of care for index hospitalization plus follow up in US dollars | The mean total costs (medical plus pharmacy costs) from patient records in each antithrombotic cohort from both the index hospitalization and the 1-month follow-up period. Results will be calculated, reported as unadjusted, and adjusted to control for the effect of covariates on outcomes | Data will be collected over a 5 year and 8 month period with this endpoint evaluated from the date of the index hospitalization to the end of the 1-month post-discharge follow-up period | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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cancer surgery, venous thromboembolism, hospitalization, anticoagulants, costs and cost analysis, thromboprophylaxis