FHIR
Release
3
(STU)
CI-Build
Terminology
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STU
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Raw JSON ( canonical form + also see JSON Format Specification )
Definition
for
Code
System
StatisticsCode
SystemStatisticsCode
{
"resourceType": "CodeSystem",
"id": "observation-statistics",
"meta": {
"lastUpdated": "2019-10-24T11:53:00+11:00"
"resourceType" : "CodeSystem",
"id" : "observation-statistics",
"meta" : {
"lastUpdated" : "2025-12-17T09:50:17.012+00:00"
},
"text": {
"status": "generated",
"div": "<div>!-- Snipped for Brevity --></div>"
"text" : {
"status" : "generated",
"div" : "<div xmlns=\"http://www.w3.org/1999/xhtml\"><p class=\"res-header-id\"><b>Generated Narrative: CodeSystem observation-statistics</b></p><a name=\"observation-statistics\"> </a><a name=\"hcobservation-statistics\"> </a><p>This case-sensitive code system <code>http://hl7.org/fhir/observation-statistics</code> defines the following codes:</p><table class=\"codes\"><tr><td style=\"white-space:nowrap\"><b>Code</b></td><td><b>Display</b></td><td><b>Definition</b></td></tr><tr><td style=\"white-space:nowrap\">average<a name=\"observation-statistics-average\"> </a></td><td>Average</td><td><div><p>The <a href=\"https://en.wikipedia.org/wiki/Arithmetic_mean\">mean</a> of N measurements over the stated period.</p>\n</div></td></tr><tr><td style=\"white-space:nowrap\">maximum<a name=\"observation-statistics-maximum\"> </a></td><td>Maximum</td><td><div><p>The <a href=\"https://en.wikipedia.org/wiki/Maximal_element\">maximum</a> value of N measurements over the stated period.</p>\n</div></td></tr><tr><td style=\"white-space:nowrap\">minimum<a name=\"observation-statistics-minimum\"> </a></td><td>Minimum</td><td><div><p>The <a href=\"https://en.wikipedia.org/wiki/Minimal_element\">minimum</a> value of N measurements over the stated period.</p>\n</div></td></tr><tr><td style=\"white-space:nowrap\">count<a name=\"observation-statistics-count\"> </a></td><td>Count</td><td><div><p>The [number] of valid measurements over the stated period that contributed to the other statistical outputs.</p>\n</div></td></tr><tr><td style=\"white-space:nowrap\">total-count<a name=\"observation-statistics-total-count\"> </a></td><td>Total Count</td><td><div><p>The total [number] of valid measurements over the stated period, including observations that were ignored because they did not contain valid result values.</p>\n</div></td></tr><tr><td style=\"white-space:nowrap\">median<a name=\"observation-statistics-median\"> </a></td><td>Median</td><td><div><p>The <a href=\"https://en.wikipedia.org/wiki/Median\">median</a> of N measurements over the stated period.</p>\n</div></td></tr><tr><td style=\"white-space:nowrap\">std-dev<a name=\"observation-statistics-std-dev\"> </a></td><td>Standard Deviation</td><td><div><p>The <a href=\"https://en.wikipedia.org/wiki/Standard_deviation\">standard deviation</a> of N measurements over the stated period.</p>\n</div></td></tr><tr><td style=\"white-space:nowrap\">sum<a name=\"observation-statistics-sum\"> </a></td><td>Sum</td><td><div><p>The <a href=\"https://en.wikipedia.org/wiki/Summation\">sum</a> of N measurements over the stated period.</p>\n</div></td></tr><tr><td style=\"white-space:nowrap\">variance<a name=\"observation-statistics-variance\"> </a></td><td>Variance</td><td><div><p>The <a href=\"https://en.wikipedia.org/wiki/Variance\">variance</a> of N measurements over the stated period.</p>\n</div></td></tr><tr><td style=\"white-space:nowrap\">20-percent<a name=\"observation-statistics-20-percent\"> </a></td><td>20th Percentile</td><td><div><p>The 20th <a href=\"https://en.wikipedia.org/wiki/Percentile\">Percentile</a> of N measurements over the stated period.</p>\n</div></td></tr><tr><td style=\"white-space:nowrap\">80-percent<a name=\"observation-statistics-80-percent\"> </a></td><td>80th Percentile</td><td><div><p>The 80th <a href=\"https://en.wikipedia.org/wiki/Percentile\">Percentile</a> of N measurements over the stated period.</p>\n</div></td></tr><tr><td style=\"white-space:nowrap\">4-lower<a name=\"observation-statistics-4-lower\"> </a></td><td>Lower Quartile</td><td><div><p>The lower <a href=\"https://en.wikipedia.org/wiki/Quartile\">Quartile</a> Boundary of N measurements over the stated period.</p>\n</div></td></tr><tr><td style=\"white-space:nowrap\">4-upper<a name=\"observation-statistics-4-upper\"> </a></td><td>Upper Quartile</td><td><div><p>The upper <a href=\"https://en.wikipedia.org/wiki/Quartile\">Quartile</a> Boundary of N measurements over the stated period.</p>\n</div></td></tr><tr><td style=\"white-space:nowrap\">4-dev<a name=\"observation-statistics-4-dev\"> </a></td><td>Quartile Deviation</td><td><div><p>The difference between the upper and lower <a href=\"https://en.wikipedia.org/wiki/Quartile\">Quartiles</a> is called the Interquartile range. (IQR = Q3-Q1) Quartile deviation or Semi-interquartile range is one-half the difference between the first and the third quartiles.</p>\n</div></td></tr><tr><td style=\"white-space:nowrap\">5-1<a name=\"observation-statistics-5-1\"> </a></td><td>1st Quintile</td><td><div><p>The lowest of four values that divide the N measurements into a frequency distribution of five classes with each containing one fifth of the total population.</p>\n</div></td></tr><tr><td style=\"white-space:nowrap\">5-2<a name=\"observation-statistics-5-2\"> </a></td><td>2nd Quintile</td><td><div><p>The second of four values that divide the N measurements into a frequency distribution of five classes with each containing one fifth of the total population.</p>\n</div></td></tr><tr><td style=\"white-space:nowrap\">5-3<a name=\"observation-statistics-5-3\"> </a></td><td>3rd Quintile</td><td><div><p>The third of four values that divide the N measurements into a frequency distribution of five classes with each containing one fifth of the total population.</p>\n</div></td></tr><tr><td style=\"white-space:nowrap\">5-4<a name=\"observation-statistics-5-4\"> </a></td><td>4th Quintile</td><td><div><p>The fourth of four values that divide the N measurements into a frequency distribution of five classes with each containing one fifth of the total population.</p>\n</div></td></tr><tr><td style=\"white-space:nowrap\">skew<a name=\"observation-statistics-skew\"> </a></td><td>Skew</td><td><div><p>Skewness is a measure of the asymmetry of the probability distribution of a real-valued random variable about its mean. The skewness value can be positive or negative, or even undefined. Source: <a href=\"https://en.wikipedia.org/wiki/Skewness\">Wikipedia</a>.</p>\n</div></td></tr><tr><td style=\"white-space:nowrap\">kurtosis<a name=\"observation-statistics-kurtosis\"> </a></td><td>Kurtosis</td><td><div><p>Kurtosis is a measure of the "tailedness" of the probability distribution of a real-valued random variable. Source: <a href=\"https://en.wikipedia.org/wiki/Kurtosis\">Wikipedia</a>.</p>\n</div></td></tr><tr><td style=\"white-space:nowrap\">regression<a name=\"observation-statistics-regression\"> </a></td><td>Regression</td><td><div><p>Linear regression is an approach for modeling two-dimensional sample points with one independent variable and one dependent variable (conventionally, the x and y coordinates in a Cartesian coordinate system) and finds a linear function (a non-vertical straight line) that, as accurately as possible, predicts the dependent variable values as a function of the independent variables. Source: <a href=\"https://en.wikipedia.org/wiki/Simple_linear_regression\">Wikipedia</a> This Statistic code will return both a gradient and an intercept value.</p>\n</div></td></tr></table></div>"
},
"extension": [
{
"url": "http://hl7.org/fhir/StructureDefinition/structuredefinition-ballot-status",
"valueString": "Informative"
},
{
"url": "http://hl7.org/fhir/StructureDefinition/structuredefinition-fmm",
"valueInteger": 0
}
],
"url": "http://hl7.org/fhir/observation-statistics",
"identifier": {
"system": "urn:ietf:rfc:3986",
"value": "urn:oid:2.16.840.1.113883.4.642.1.395"
"extension" : [{
"url" : "http://hl7.org/fhir/StructureDefinition/structuredefinition-wg",
"valueCode" : "oo"
}],
"url" : "http://hl7.org/fhir/observation-statistics",
"identifier" : [{
"system" : "urn:ietf:rfc:3986",
"value" : "urn:oid:2.16.840.1.113883.4.642.1.1126"
},
"version": "3.0.2",
"name": "StatisticsCode",
"status": "draft",
"experimental": false,
"date": "2019-10-24T11:53:00+11:00",
"publisher": "HL7 (FHIR Project)",
"contact": [
{
"telecom": [
{
"system": "url",
"value": "http://hl7.org/fhir"
},
{
"system": "email",
"value": "fhir@lists.hl7.org"
}
]
}
],
"description": "The statistical operation parameter -\"statistic\" - codes",
"caseSensitive": true,
"valueSet": "http://hl7.org/fhir/ValueSet/observation-statistics",
"content": "complete",
"concept": [
{
"code": "average",
"display": "Average",
"definition": "The [mean](https://en.wikipedia.org/wiki/Arithmetic_mean) of N measurements over the stated period"
},
{
"code": "maximum",
"display": "Maximum",
"definition": "The [maximum](https://en.wikipedia.org/wiki/Maximal_element) value of N measurements over the stated period"
},
{
"code": "minimum",
"display": "Minimum",
"definition": "The [minimum](https://en.wikipedia.org/wiki/Minimal_element) value of N measurements over the stated period"
},
{
"code": "count",
"display": "Count",
"definition": "The [number] of valid measurements over the stated period that contributed to the other statistical outputs"
},
{
"code": "totalcount",
"display": "Total Count",
"definition": "The total [number] of valid measurements over the stated period, including observations that were ignored because they did not contain valid result values"
},
{
"code": "median",
"display": "Median",
"definition": "The [median](https://en.wikipedia.org/wiki/Median) of N measurements over the stated period"
},
{
"code": "std-dev",
"display": "Standard Deviation",
"definition": "The [standard deviation](https://en.wikipedia.org/wiki/Standard_deviation) of N measurements over the stated period"
},
{
"code": "sum",
"display": "Sum",
"definition": "The [sum](https://en.wikipedia.org/wiki/Summation) of N measurements over the stated period"
},
{
"code": "variance",
"display": "Variance",
"definition": "The [variance](https://en.wikipedia.org/wiki/Variance) of N measurements over the stated period"
},
{
"code": "20-percent",
"display": "20th Percentile",
"definition": "The 20th [Percentile](https://en.wikipedia.org/wiki/Percentile) of N measurements over the stated period"
},
{
"code": "80-percent",
"display": "80th Percentile",
"definition": "The 80th [Percentile](https://en.wikipedia.org/wiki/Percentile) of N measurements over the stated period"
},
{
"code": "4-lower",
"display": "Lower Quartile",
"definition": "The lower [Quartile](https://en.wikipedia.org/wiki/Quartile) Boundary of N measurements over the stated period"
},
{
"code": "4-upper",
"display": "Upper Quartile",
"definition": "The upper [Quartile](https://en.wikipedia.org/wiki/Quartile) Boundary of N measurements over the stated period"
},
{
"code": "4-dev",
"display": "Quartile Deviation",
"definition": "The difference between the upper and lower [Quartiles](https://en.wikipedia.org/wiki/Quartile) is called the Interquartile range. (IQR = Q3-Q1) Quartile deviation or Semi-interquartile range is one-half the difference between the first and the third quartiles."
},
{
"code": "5-1",
"display": "1st Quintile",
"definition": "The lowest of four values that divide the N measurements into a frequency distribution of five classes with each containing one fifth of the total population"
},
{
"code": "5-2",
"display": "2nd Quintile",
"definition": "The second of four values that divide the N measurements into a frequency distribution of five classes with each containing one fifth of the total population"
},
{
"code": "5-3",
"display": "3rd Quintile",
"definition": "The third of four values that divide the N measurements into a frequency distribution of five classes with each containing one fifth of the total population"
},
{
"code": "5-4",
"display": "4th Quintile",
"definition": "The fourth of four values that divide the N measurements into a frequency distribution of five classes with each containing one fifth of the total population"
},
{
"code": "skew",
"display": "Skew",
"definition": "Skewness is a measure of the asymmetry of the probability distribution of a real-valued random variable about its mean. The skewness value can be positive or negative, or even undefined. Source: [Wikipedia](https://en.wikipedia.org/wiki/Skewness)"
},
{
"code": "kurtosis",
"display": "Kurtosis",
"definition": "Kurtosis is a measure of the \"tailedness\" of the probability distribution of a real-valued random variable. Source: [Wikipedia](https://en.wikipedia.org/wiki/Kurtosis)"
{
"use" : "old",
"system" : "urn:ietf:rfc:3986",
"value" : "urn:oid:2.16.840.1.113883.4.642.1.395"
}],
"version" : "6.0.0-ballot3",
"name" : "StatisticsCode",
"title" : "Statistics Code",
"status" : "active",
"experimental" : false,
"date" : "2022-12-01T09:29:23+11:00",
"publisher" : "HL7 (FHIR Project)",
"contact" : [{
"telecom" : [{
"system" : "url",
"value" : "http://hl7.org/fhir"
},
{
"code": "regression",
"display": "Regression",
"definition": "Linear regression is an approach for modeling two-dimensional sample points with one independent variable and one dependent variable (conventionally, the x and y coordinates in a Cartesian coordinate system) and finds a linear function (a non-vertical straight line) that, as accurately as possible, predicts the dependent variable values as a function of the independent variables. Source: [Wikipedia](https://en.wikipedia.org/wiki/Simple_linear_regression) This Statistic code will return both a gradient and an intercept value."
}
]
"system" : "email",
"value" : "fhir@lists.hl7.org"
}]
}],
"description" : "The statistical operation parameter -\"statistic\" codes.",
"jurisdiction" : [{
"coding" : [{
"system" : "http://unstats.un.org/unsd/methods/m49/m49.htm",
"code" : "001",
"display" : "World"
}]
}],
"caseSensitive" : true,
"valueSet" : "http://hl7.org/fhir/ValueSet/observation-statistics",
"content" : "complete",
"concept" : [{
"code" : "average",
"display" : "Average",
"definition" : "The [mean](https://en.wikipedia.org/wiki/Arithmetic_mean) of N measurements over the stated period."
},
{
"code" : "maximum",
"display" : "Maximum",
"definition" : "The [maximum](https://en.wikipedia.org/wiki/Maximal_element) value of N measurements over the stated period."
},
{
"code" : "minimum",
"display" : "Minimum",
"definition" : "The [minimum](https://en.wikipedia.org/wiki/Minimal_element) value of N measurements over the stated period."
},
{
"code" : "count",
"display" : "Count",
"definition" : "The [number] of valid measurements over the stated period that contributed to the other statistical outputs."
},
{
"code" : "total-count",
"display" : "Total Count",
"definition" : "The total [number] of valid measurements over the stated period, including observations that were ignored because they did not contain valid result values."
},
{
"code" : "median",
"display" : "Median",
"definition" : "The [median](https://en.wikipedia.org/wiki/Median) of N measurements over the stated period."
},
{
"code" : "std-dev",
"display" : "Standard Deviation",
"definition" : "The [standard deviation](https://en.wikipedia.org/wiki/Standard_deviation) of N measurements over the stated period."
},
{
"code" : "sum",
"display" : "Sum",
"definition" : "The [sum](https://en.wikipedia.org/wiki/Summation) of N measurements over the stated period."
},
{
"code" : "variance",
"display" : "Variance",
"definition" : "The [variance](https://en.wikipedia.org/wiki/Variance) of N measurements over the stated period."
},
{
"code" : "20-percent",
"display" : "20th Percentile",
"definition" : "The 20th [Percentile](https://en.wikipedia.org/wiki/Percentile) of N measurements over the stated period."
},
{
"code" : "80-percent",
"display" : "80th Percentile",
"definition" : "The 80th [Percentile](https://en.wikipedia.org/wiki/Percentile) of N measurements over the stated period."
},
{
"code" : "4-lower",
"display" : "Lower Quartile",
"definition" : "The lower [Quartile](https://en.wikipedia.org/wiki/Quartile) Boundary of N measurements over the stated period."
},
{
"code" : "4-upper",
"display" : "Upper Quartile",
"definition" : "The upper [Quartile](https://en.wikipedia.org/wiki/Quartile) Boundary of N measurements over the stated period."
},
{
"code" : "4-dev",
"display" : "Quartile Deviation",
"definition" : "The difference between the upper and lower [Quartiles](https://en.wikipedia.org/wiki/Quartile) is called the Interquartile range. (IQR = Q3-Q1) Quartile deviation or Semi-interquartile range is one-half the difference between the first and the third quartiles."
},
{
"code" : "5-1",
"display" : "1st Quintile",
"definition" : "The lowest of four values that divide the N measurements into a frequency distribution of five classes with each containing one fifth of the total population."
},
{
"code" : "5-2",
"display" : "2nd Quintile",
"definition" : "The second of four values that divide the N measurements into a frequency distribution of five classes with each containing one fifth of the total population."
},
{
"code" : "5-3",
"display" : "3rd Quintile",
"definition" : "The third of four values that divide the N measurements into a frequency distribution of five classes with each containing one fifth of the total population."
},
{
"code" : "5-4",
"display" : "4th Quintile",
"definition" : "The fourth of four values that divide the N measurements into a frequency distribution of five classes with each containing one fifth of the total population."
},
{
"code" : "skew",
"display" : "Skew",
"definition" : "Skewness is a measure of the asymmetry of the probability distribution of a real-valued random variable about its mean. The skewness value can be positive or negative, or even undefined. Source: [Wikipedia](https://en.wikipedia.org/wiki/Skewness)."
},
{
"code" : "kurtosis",
"display" : "Kurtosis",
"definition" : "Kurtosis is a measure of the \"tailedness\" of the probability distribution of a real-valued random variable. Source: [Wikipedia](https://en.wikipedia.org/wiki/Kurtosis)."
},
{
"code" : "regression",
"display" : "Regression",
"definition" : "Linear regression is an approach for modeling two-dimensional sample points with one independent variable and one dependent variable (conventionally, the x and y coordinates in a Cartesian coordinate system) and finds a linear function (a non-vertical straight line) that, as accurately as possible, predicts the dependent variable values as a function of the independent variables. Source: [Wikipedia](https://en.wikipedia.org/wiki/Simple_linear_regression) This Statistic code will return both a gradient and an intercept value."
}]
}
Usage note: every effort has been made to ensure that the examples are correct and useful, but they are not a normative part of the specification.
FHIR
®©
HL7.org
2011+.
FHIR
Release
3
(STU;
v3.0.2-11200)
R6
hl7.fhir.core#6.0.0-ballot3
generated
on
Thurs,
Oct
24,
2019
11:53+1100.
QA
Page
Wed,
Dec
17,
2025
09:51+0000.
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