---
type: "example"
title: "Evidence Example: evidence-example-statistic-model-include-if"
resource: "Evidence"
example: "evidence-example-statistic-model-include-if"
---
# Evidence Example: evidence-example-statistic-model-include-if

## Example XML



```xml
<?xml version="1.0" encoding="UTF-8"?>

<Evidence xmlns="http://hl7.org/fhir">
	<id value="example-statistic-model-include-if"/>
	<meta>
		<versionId value="9"/>
		<lastUpdated value="2025-03-10T14:59:32.227Z"/>
		<profile value="http://hl7.org/fhir/uv/ebm/StructureDefinition/statistic-model"/>
	</meta>
	<url value="http://hl7.org/fhir/Evidence/example-statistic-model-include-if"/>
	<identifier>
		<type>
			<text value="FEvIR Object Identifier"/>
		</type>
		<system value="urn:ietf:rfc:3986"/>
		<value value="https://fevir.net/FOI/346428"/>
		<assigner>
			<display value="Computable Publishing LLC"/>
		</assigner>
	</identifier>
	<title value="Example of statistical analysis plan with different statistical test if non-normal distribution"/>
	<status value="active"/>
	<author>
		<name value="Brian S. Alper, MD, MSPH"/>
	</author>
	<publisher value="Computable Publishing LLC"/>
	<contact>
		<telecom>
			<system value="email"/>
			<value value="support@computablepublishing.com"/>
		</telecom>
	</contact>
	<copyright value="https://creativecommons.org/licenses/by-nc-sa/4.0/"/>
	<description value="This example uses the StatisticModelIncludeIf extension to represent the model characteristic of Welch&apos;s 2-sample t-test if the data is consistent with a normal distribution (based on Shapiro-Wilk test with p-value &gt;= 0.05) and a Wilcoxon Mann-Whitney test if not."/>
	<variableDefinition>
		<description value="Adults with hypertension"/>
		<variableRole value="population"/>
	</variableDefinition>
	<variableDefinition>
		<description value="Reversitol vs. Placebo"/>
		<variableRole value="exposure"/>
	</variableDefinition>
	<variableDefinition>
		<description value="Change in systolic blood pressure from baseline to 3 months"/>
		<variableRole value="outcome"/>
	</variableDefinition>
	<studyDesign>
		<coding>
			<system value="https://fevir.net/sevco"/>
			<code value="SEVCO:01003"/>
			<display value="randomized assignment"/>
		</coding>
	</studyDesign>
	<statistic>
		<statisticType>
			<coding>
				<system value="https://fevir.net/sevco"/>
				<code value="STATO:0000457"/>
				<display value="difference in means"/>
			</coding>
		</statisticType>
		<modelCharacteristic>
			<extension url="http://hl7.org/fhir/StructureDefinition/statistic-model-include-if">
				<extension url="attribute">
					<valueCodeableConcept>
						<text value="data distribution"/>
					</valueCodeableConcept>
				</extension>
				<extension url="value">
					<valueCodeableConcept>
						<text value="normal distribution (Shapiro-Wilk test with p-value &gt;= 0.05)"/>
					</valueCodeableConcept>
				</extension>
			</extension>
			<code>
				<text value="Welch&apos;s 2-sample t-test"/>
			</code>
			<intended value="true"/>
		</modelCharacteristic>
		<modelCharacteristic>
			<extension url="http://hl7.org/fhir/StructureDefinition/statistic-model-include-if">
				<extension url="attribute">
					<valueCodeableConcept>
						<text value="data distribution"/>
					</valueCodeableConcept>
				</extension>
				<extension url="value">
					<valueCodeableConcept>
						<text value="not consistent with normal distribution (Shapiro-Wilk test with p-value &lt; 0.05)"/>
					</valueCodeableConcept>
				</extension>
			</extension>
			<code>
				<text value="Wilcoxon Mann-Whitney test"/>
			</code>
			<intended value="true"/>
		</modelCharacteristic>
	</statistic>
</Evidence>
```