{
  "resourceType": "CodeSystem",
  "id": "observation-statistics",
  "meta": {
    "lastUpdated": "2017-04-18T21:44:43.294+00:00"
  },
  "text": {
    "status": "generated",
    "div": "<div xmlns=\"http://www.w3.org/1999/xhtml\"><h2>StatisticsCode</h2><div><p>The statistical operation parameter -\"statistic\" -  codes</p></div><p>This code system http://hl7.org/fhir/observation-statistics defines the following codes:</p><table class=\"codes\"><tr><td><b>Code</b></td><td><b>Display</b></td><td><b>Definition</b></td></tr><tr><td>average\r\n                  <a name=\"observation-statistics-average\"></a></td><td>Average</td><td>The [mean](https://en.wikipedia.org/wiki/Arithmetic_mean) of N measurements over the stated period</td></tr><tr><td>maximum\r\n                  <a name=\"observation-statistics-maximum\"></a></td><td>Maximum</td><td>The [maximum](https://en.wikipedia.org/wiki/Maximal_element) value of N measurements over the stated period</td></tr><tr><td>minimum\r\n                  <a name=\"observation-statistics-minimum\"></a></td><td>Minimum</td><td>The [minimum](https://en.wikipedia.org/wiki/Minimal_element) value of N measurements over the stated period</td></tr><tr><td>count\r\n                  <a name=\"observation-statistics-count\"></a></td><td>Count</td><td>The [number] of valid measurements over the stated period that contributed to the other statistical outputs</td></tr><tr><td>totalcount\r\n                  <a name=\"observation-statistics-totalcount\"></a></td><td>Total Count</td><td>The total [number] of valid measurements over the stated period, including observations that were ignored because they did not contain valid result values</td></tr><tr><td>median\r\n                  <a name=\"observation-statistics-median\"></a></td><td>Median</td><td>The [median](https://en.wikipedia.org/wiki/Median) of N measurements over the stated period</td></tr><tr><td>std-dev\r\n                  <a name=\"observation-statistics-std-dev\"></a></td><td>Standard Deviation</td><td>The [standard deviation](https://en.wikipedia.org/wiki/Standard_deviation) of N measurements over the stated period</td></tr><tr><td>sum\r\n                  <a name=\"observation-statistics-sum\"></a></td><td>Sum</td><td>The [sum](https://en.wikipedia.org/wiki/Summation) of N measurements over the stated period</td></tr><tr><td>variance\r\n                  <a name=\"observation-statistics-variance\"></a></td><td>Variance</td><td>The [variance](https://en.wikipedia.org/wiki/Variance) of N measurements over the stated period</td></tr><tr><td>20-percent\r\n                  <a name=\"observation-statistics-20-percent\"></a></td><td>20th Percentile</td><td>The 20th [Percentile](https://en.wikipedia.org/wiki/Percentile) of N measurements over the stated period</td></tr><tr><td>80-percent\r\n                  <a name=\"observation-statistics-80-percent\"></a></td><td>80th Percentile</td><td>The 80th [Percentile](https://en.wikipedia.org/wiki/Percentile) of N measurements over the stated period</td></tr><tr><td>4-lower\r\n                  <a name=\"observation-statistics-4-lower\"></a></td><td>Lower Quartile</td><td>The lower [Quartile](https://en.wikipedia.org/wiki/Quartile) Boundary of N measurements over the stated period</td></tr><tr><td>4-upper\r\n                  <a name=\"observation-statistics-4-upper\"></a></td><td>Upper Quartile</td><td>The upper [Quartile](https://en.wikipedia.org/wiki/Quartile) Boundary of N measurements over the stated period</td></tr><tr><td>4-dev\r\n                  <a name=\"observation-statistics-4-dev\"></a></td><td>Quartile Deviation</td><td>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.</td></tr><tr><td>5-1\r\n                  <a name=\"observation-statistics-5-1\"></a></td><td>1st Quintile</td><td>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</td></tr><tr><td>5-2\r\n                  <a name=\"observation-statistics-5-2\"></a></td><td>2nd Quintile</td><td>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</td></tr><tr><td>5-3\r\n                  <a name=\"observation-statistics-5-3\"></a></td><td>3rd Quintile</td><td>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</td></tr><tr><td>5-4\r\n                  <a name=\"observation-statistics-5-4\"></a></td><td>4th Quintile</td><td>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</td></tr><tr><td>skew\r\n                  <a name=\"observation-statistics-skew\"></a></td><td>Skew</td><td>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)</td></tr><tr><td>kurtosis\r\n                  <a name=\"observation-statistics-kurtosis\"></a></td><td>Kurtosis</td><td>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)</td></tr><tr><td>regression\r\n                  <a name=\"observation-statistics-regression\"></a></td><td>Regression</td><td>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.</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"
  },
  "version": "3.0.1",
  "name": "StatisticsCode",
  "status": "draft",
  "experimental": false,
  "date": "2017-04-18T21:44:43+00:00",
  "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)"
    },
    {
      "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."
    }
  ]
}