--- title: Hypothesis Testing Example - Thrombosis Research - One Roc Curve description: Hypothesis Testing Example - Use nQuery and learn how to calculate sample size and use a power analysis calculator for clinical trials. This example focuses on Thrombosis Research. image: https://www.statsols.com/hubfs/Master_Images/___HeroBannerImages/nQuery%20Sample%20Size%20Software%20Image.jpg --- Explore the Scientific R&D Platform ![Top Bar background texture](https://flow-cytometry.net/wp-content/uploads/2024/07/nav-bg.png) ![](https://flow-cytometry.net/wp-content/uploads/2024/07/Luma-TM.png) Scientific intelligence platform for AI-powered data management and workflow automation [Explore Luma   ](https://www.dotmatics.com/luma-data-management-platform) [![Prism logo](https://flow-cytometry.net/wp-content/uploads/2024/07/Prism-Logo-White-2.png) Statistical analysis and graphing software for scientists ](https://www.graphpad.com/?utm_medium=referral&utm_source=nquery&utm_campaign=dotmatics-top-bar) [![Geneious logo](https://flow-cytometry.net/wp-content/uploads/2024/07/Geneious-Logo-White-2.png) Bioinformatics, cloning, and antibody discovery software ](https://www.geneious.com/?utm_medium=referral&utm_source=nquery&utm_campaign=dotmatics-top-bar) [![SnapGene logo](https://cdn.labarchives.com/assets/16.23.0/assets/images/dotmatics/lab-archives/top-bar/PreNav-Logo-SnapGene.svg) Plan, visualize, & document core molecular biology procedures ](https://www.snapgene.com/?utm_medium=referral&utm_source=nquery&utm_campaign=dotmatics-top-bar) [![Protein Metrics logo](https://cdn.labarchives.com/assets/16.23.0/assets/images/dotmatics/lab-archives/top-bar/PreNav-Logo-Protein-Metrics.svg) Proteomics software for analysis of mass spec data ](https://proteinmetrics.com/?utm_medium=referral&utm_source=nquery&utm_campaign=dotmatics-top-bar) [![LabArchives logo](https://flow-cytometry.net/wp-content/uploads/2024/07/LabArchives-Logo-White-2.png) Electronic Lab Notebook to organize, search and share data ](https://www.labarchives.com/?utm_medium=referral&utm_source=nquery&utm_campaign=dotmatics-top-bar) [![OMIQ logo](https://cdn.labarchives.com/assets/16.23.0/assets/images/dotmatics/lab-archives/top-bar/PreNav-Logo-OMIQ.svg) Modern cytometry analysis platform ](https://www.omiq.ai/?utm_medium=referral&utm_source=nquery&utm_campaign=dotmatics-top-bar) [![FCS Express logo](https://cdn.labarchives.com/assets/16.23.0/assets/images/dotmatics/lab-archives/top-bar/PreNav-Logo-FCS-Express.svg) Analysis, statistics, graphing and reporting of flow cytometry data ](https://denovosoftware.com/?utm_medium=referral&utm_source=nquery&utm_campaign=dotmatics-top-bar) [![Easy Panel logo](https://flow-cytometry.net/wp-content/uploads/2024/07/EasyPanel-Logo-White-2.png) Intelligent panel design & inventory management for flow cytometry ](https://flow-cytometry.net/?utm_medium=referral&utm_source=nquery&utm_campaign=dotmatics-top-bar) [![nQuery logo](https://cdn.labarchives.com/assets/16.23.0/assets/images/dotmatics/lab-archives/top-bar/PreNav-Logo-nQuery.svg) Software to optimize designs of clinical trials ](https://www.statsols.com/) [![M-Star logo](https://flow-cytometry.net/wp-content/uploads/2024/07/M-Star-Logo-White-2.png) Computational fluid dynamics (CFD) software for engineers and researchers ](https://www.mstarcfd.com/?utm_medium=referral&utm_source=nquery&utm_campaign=dotmatics-top-bar) [![SoftGenetics logo](https://flow-cytometry.net/wp-content/uploads/2024/07/SoftGenetics-Logo-White-2.png) Genetic analysis software for research, forensics & healthcare applications ](https://softgenetics.com/?utm_medium=referral&utm_source=nquery&utm_campaign=dotmatics-top-bar) [Explore the Scientific Software   ](https://www.dotmatics.com/portfolio) [![nQuery Logo](https://www.statsols.com/hubfs/nQuery%20Logo.svg "nQuery Logo")](https://www.statsols.com/) [![Pricing](https://no-cache.hubspot.com/cta/default/488764/23ddd076-07af-4f0a-9388-5a58a5369002.png)](https://cta-redirect.hubspot.com/cta/redirect/488764/23ddd076-07af-4f0a-9388-5a58a5369002) [![Free Trial](https://no-cache.hubspot.com/cta/default/488764/93ddde0f-93b2-4893-a3db-0523d2334739.png)](https://cta-redirect.hubspot.com/cta/redirect/488764/93ddde0f-93b2-4893-a3db-0523d2334739) # Sample Size Determination Example ## AREA: Agreement | Cardiology ![nQuery In Use Background Web Opacity 35](https://www.statsols.com/hs-fs/hubfs/Master_Images/___HeroBannerImages/nQuery%20In%20Use%20Background%20Web%20%20Opacity%2035.png?width=1920&name=nQuery%20In%20Use%20Background%20Web%20%20Opacity%2035.png "nQuery In Use Background Web Opacity 35") #### Thrombosis Research #### Title: Intrinsic Platelet Reactivity and Thrombus Burden in Patients with ST- Elevation Myocardial Infarction **Objective: **In patients with ST elevation myocardial infarction (STEMI) increased platelet reactivity has been described to affect the primary percutanuous coronary intervention (PPCI) outcome. We aimed to evaluate the predictive accuracy of intrinsic platelet reactivity for intracoronary thrombus burden in P2Y12 inhibitor- naïve STEMI patients. **Year:** 2013 **Source: **Thrombosis Research   **Link:** [http://www.sciencedirect.com/science/article/pii/S0049384813000546 ](http://www.sciencedirect.com/science/article/pii/S0049384813000546) **Clinical Area:** Cardiology | **Sample Size Section in Paper/Protocol:** | | --- | | “The predictive accuracy of intrinsic PR for the presence of high thrombus burden was assessed by Receiver Operating Characteristic (ROC) analysis. Power analysis was performed with a two-sided z-test [12]. A sample of 59 patients from the high thrombus burden (HTB) group and 24 patients from the low thrombus burden (LTB) group (assuming an allocation ratio HTB group/LTB group of 2.5:1, based on our own preliminary data) would suffice for a 85% power to detect a difference of 0.2 between the area under the curve (AUC), under the null hypothesis of AUC = 0.5 (no diagnostic accuracy) and the alternative hypothesis of AUC = 0.7 (moderate diagnostic accuracy), at a significance level of 0.05.” | ** Summary of Necessary Parameter Estimates for Sample Size Calculation:** | ** Parameter** | **Value** | | --- | --- | |  Significance Level | 0.05 | |  Discrete or Continuous  | Continuous | |  Null Hypothesis AUC | 0.05 | |  Alternative Hypothesis AUC | 0.07 | |  Sample Size Ratio | 0.4 | | Power | 85 | #### **Email me this example in PDF format** **Step 1: **Select the** ‘One ROC Curve’** table from the Select Test Design & Goal window as pictured below. This can be done **using the radio buttons** or alternatively, you can** use the search bar** at the end of the Select Test Design & Goal window. ![Sample Size Calculator Example- nQuery- Example 02- Img 01- One ROC Curve](https://www.statsols.com/hs-fs/hubfs/Master_Images/___PageImages/Worked%20Examples/nQuery%20Example%20Images/Sample%20Size%20Calculator%20Example-%20nQuery-%20Example%2002-%20Img%2001-%20One%20ROC%20Curve.png?width=586&name=Sample%20Size%20Calculator%20Example-%20nQuery-%20Example%2002-%20Img%2001-%20One%20ROC%20Curve.png) **Step 2: **Enter the parameter values for sample size calculation taken from the study design. ![Sample Size Calculator Example- nQuery- Example 02- Img 02- One ROC Curve](https://www.statsols.com/hs-fs/hubfs/Master_Images/___PageImages/Worked%20Examples/nQuery%20Example%20Images/Sample%20Size%20Calculator%20Example-%20nQuery-%20Example%2002-%20Img%2002-%20One%20ROC%20Curve.png?width=778&name=Sample%20Size%20Calculator%20Example-%20nQuery-%20Example%2002-%20Img%2002-%20One%20ROC%20Curve.png) **Step 3: **Select “**Calculate required overall sample size given the sample size ratio (N-/N+) for a given power**”, click the **“Run**” button to solve for the sample size. | This gives a sample size of 59 positive cases and 29 negative cases as per the study Design | | --- | ![Sample Size Calculator Example- nQuery- Example 02- Img 03- One ROC Curve](https://www.statsols.com/hs-fs/hubfs/Master_Images/___PageImages/Worked%20Examples/nQuery%20Example%20Images/Sample%20Size%20Calculator%20Example-%20nQuery-%20Example%2002-%20Img%2003-%20One%20ROC%20Curve.png?width=512&name=Sample%20Size%20Calculator%20Example-%20nQuery-%20Example%2002-%20Img%2003-%20One%20ROC%20Curve.png) **Note: **When using nQuery Advanced, both the Positive and Negative Sample Size will be auto-calculated once the Power (%) value is entered. **Step 4: **Once the calculation is completed, nQuery Advanced provides an output statement summarizing the results. It States: | **Output Statement:** | | --- | | “In a two sided test comparing the area under the ROC curve (AUC) to a reference value for continuous response data using a z-test approximation, a sample size of 59 from the positive group (with the condition) and a sample size of 24 from the negative group (without the condition) achieves 85.28% power at the 5% significance level when the AUC under the null hypothesis is 0.5 and the AUC under the alternative hypothesis is 0.7.”   |    ![Sample Size Calculator Example- nQuery- Example 02- Img 04- One ROC Curve](https://www.statsols.com/hs-fs/hubfs/Master_Images/___PageImages/Worked%20Examples/nQuery%20Example%20Images/Sample%20Size%20Calculator%20Example-%20nQuery-%20Example%2002-%20Img%2004-%20One%20ROC%20Curve.png?width=727&name=Sample%20Size%20Calculator%20Example-%20nQuery-%20Example%2002-%20Img%2004-%20One%20ROC%20Curve.png)   #### **Email me this example in PDF format** ### Free 14 Day Trial ![Demo Icon white](https://www.statsols.com/hs-fs/hubfs/Demo%20Icon%20white.png?width=330&name=Demo%20Icon%20white.png) **No download required**   [Try Now](https://www.statsols.com/nquery-demo) ##### **LOCATION** GraphPad Software DBA Statistical Solutions, 225 Franklin St FL 26 Boston, MA, 02110-2853, United States Copyright © Statsols. 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