This case-sensitive code system `http://terminology.hl7.org/CodeSystem/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. |