<status value="active"/><experimental value="false"/><date value="2022-12-01T09:29:23+11:00"/><publisher value="HL7 (FHIR Project)"/><contact><telecom><system value="url"/><value value="http://hl7.org/fhir"/></telecom><telecom><system value="email"/><value value="fhir@lists.hl7.org"/></telecom></contact><description value="The statistical operation parameter -"statistic" codes."/><jurisdiction><coding><system value="http://unstats.un.org/unsd/methods/m49/m49.htm"/><code value="001"/><display value="World"/></coding></jurisdiction><caseSensitive value="true"/><valueSet value="http://hl7.org/fhir/ValueSet/observation-statistics"/><content value="complete"/><concept><code value="average"/><display value="Average"/><definition value="The [mean](https://en.wikipedia.org/wiki/Arithmetic_mean) of N measurements over the stated period."/></concept><concept><code value="maximum"/><display value="Maximum"/><definition value="The [maximum](https://en.wikipedia.org/wiki/Maximal_element) value of N measurements over the stated period."/></concept><concept><code value="minimum"/><display value="Minimum"/><definition value="The [minimum](https://en.wikipedia.org/wiki/Minimal_element) value of N measurements over the stated period."/></concept><concept><code value="count"/><display value="Count"/><definition value="The [number] of valid measurements over the stated period that contributed to the other statistical outputs."/></concept><concept><code value="total-count"/><display value="Total Count"/><definition value="The total [number] of valid measurements over the stated period, including observations that were ignored because they did not contain valid result values."/></concept><concept><code value="median"/><display value="Median"/><definition value="The [median](https://en.wikipedia.org/wiki/Median) of N measurements over the stated period."/></concept><concept><code value="std-dev"/><display value="Standard Deviation"/><definition value="The [standard deviation](https://en.wikipedia.org/wiki/Standard_deviation) of N measurements over the stated period."/></concept><concept><code value="sum"/><display value="Sum"/><definition value="The [sum](https://en.wikipedia.org/wiki/Summation) of N measurements over the stated period."/></concept><concept><code value="variance"/><display value="Variance"/><definition value="The [variance](https://en.wikipedia.org/wiki/Variance) of N measurements over the stated period."/></concept><concept><code value="20-percent"/><display value="20th Percentile"/><definition value="The 20th [Percentile](https://en.wikipedia.org/wiki/Percentile) of N measurements over the stated period."/></concept><concept><code value="80-percent"/><display value="80th Percentile"/><definition value="The 80th [Percentile](https://en.wikipedia.org/wiki/Percentile) of N measurements over the stated period."/></concept><concept><code value="4-lower"/><display value="Lower Quartile"/><definition value="The lower [Quartile](https://en.wikipedia.org/wiki/Quartile) Boundary of N measurements over the stated period."/></concept><concept><code value="4-upper"/><display value="Upper Quartile"/><definition value="The upper [Quartile](https://en.wikipedia.org/wiki/Quartile) Boundary of N measurements over the stated period."/></concept><concept><code value="4-dev"/><display value="Quartile Deviation"/><definition value="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."/></concept><concept><code value="5-1"/><display value="1st Quintile"/><definition value="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."/></concept><concept><code value="5-2"/><display value="2nd Quintile"/><definition value="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."/></concept><concept><code value="5-3"/><display value="3rd Quintile"/><definition value="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."/></concept><concept><code value="5-4"/><display value="4th Quintile"/><definition value="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."/></concept><concept><code value="skew"/><display value="Skew"/><definition value="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)."/></concept><concept><code value="kurtosis"/><display value="Kurtosis"/><definition value="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)."/></concept><concept><code value="regression"/><display value="Regression"/><definition value="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."/></concept></CodeSystem>

Generated Narrative: CodeSystem observation-statistics

This case-sensitive code system http://hl7.org/fhir/observation-statistics defines the following codes:

Code	Display	Definition
average	Average	The mean of N measurements over the stated period.
maximum	Maximum	The maximum value of N measurements over the stated period.
minimum	Minimum	The minimum value of N measurements over the stated period.
count	Count	The [number] of valid measurements over the stated period that contributed to the other statistical outputs.
total-count	Total Count	The total [number] of valid measurements over the stated period, including observations that were ignored because they did not contain valid result values.
median	Median	The median of N measurements over the stated period.
std-dev	Standard Deviation	The standard deviation of N measurements over the stated period.
sum	Sum	The sum of N measurements over the stated period.
variance	Variance	The variance of N measurements over the stated period.
20-percent	20th Percentile	The 20th Percentile of N measurements over the stated period.
80-percent	80th Percentile	The 80th Percentile of N measurements over the stated period.
4-lower	Lower Quartile	The lower Quartile Boundary of N measurements over the stated period.
4-upper	Upper Quartile	The upper Quartile Boundary of N measurements over the stated period.
4-dev	Quartile Deviation	The difference between the upper and lower Quartiles 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.
5-1	1st Quintile	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.
5-2	2nd Quintile	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.
5-3	3rd Quintile	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.
5-4	4th Quintile	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.
skew	Skew	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.
kurtosis	Kurtosis	Kurtosis is a measure of the "tailedness" of the probability distribution of a real-valued random variable. Source: Wikipedia.
regression	Regression	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 This Statistic code will return both a gradient and an intercept value.