Content Comparison

Name:

Median Observation

Aggregated For:

Continuous variable measures

Definition:

The measure's midpoint observed value for those cases represented in the data element Population for the month.

The observed value is the Measurement Value that is calculated for each case as it is processed through the algorithm and received a measure category assignment = ‘D’ for the measure or stratum.

To determine the Median, sort the case-level cases by their observed values from the highest value to lowest value:

If the total number of Population cases is odd

then Median Observation = the value associated to the middle case

ELSE

If the total number of Population cases is even

then Median Observation = the average of the values of the two middle cases

NOTE:The calculated Median Observation does not have to be an observed value of the data.

Allowable Values:

0 through 10,000,000.000 (calculate to 4 decimals and round to 3 decimals where 5 rounds up)

Edits:

• If Population or Initial Population = zero, then Median Observation may not be entered.

• See edits for the Mean Observation data element.

Name:

Population

Aggregated For:

Continuous variable measures

Definition:

The total number of cases that are members of a measure's population for the hospital during the specified time period. This is the count of all patient-level records with a Category Assignment = ‘D’ for the measure or strata.

Aggregate all case-level records that are members of a measure's population. Do not eliminate or suppress outliers.

Note: Cases with a Category Assignment of ‘Y’ should not be included in the Population count. These cases are missing data that prevents the calculation of the measure’s Measurement Value.

To calculate the Mean Observation and Standard Deviation of the Observation, the Population count must only include those cases for which the Measurement Value was calculated. For this reason, the Population count must only include those cases with a Category Assignment of ‘D'.

Allowable Values:

0 through 10,000,000 (whole numbers only)

Note:  Hospitals entering a zero for this data element will be required to attest that they have no cases in the denominator cases (i.e., ‘zero denominator’) for the measure for the month. Hospitals with denominator cases are expected to enter the appropriate value for each measure or strata.

Edits:

• Population <= Hospital Sample Size

• Stratified measures where the Overall measure (e.g., ED-1, ED-2) is reported

  • The sum of each stratum Population must be = Overall Population for the measure (e.g., strata Population for ED-1b + strata Population for ED-1c) must = Overall Population for ED-1a)

Name:

Standard Deviation of the Observation

Aggregated For:

Continuous variable measures

Definition:

The standard deviation of the observed value for those cases represented in the data element Population for the month.

The observed value is the Measurement Value that is calculated for each case as it is processed through the algorithm and received a measure category assignment = ‘D’ for the measure or strata.

Standard Deviation of the Observation =

Square root of the [sum of the (Measurement Value for all cases minus (-) Mean Observation )² divided by (Population count - 1)], where the Mean Observation (Mean time in minutes) and Population count were previously derived.

where m = the Population count for the measure or strata

Allowable Values:

0 through 10,000,000 .000 (calculate to 4 decimals and round to 3 decimals where 5 rounds up)

Edits:

• If Population or Initial Population = zero, then Standard Deviation of the Observation may not be entered.

• Standard Deviation of the Observed Values must be >= 0

• If Population = 1, then the Standard Deviation of the Observation cannot be entered.

Note:  When Population = 1, the Standard Deviation cannot be calculated because a ‘divide by zero’ error will occur in the equation. In this case, no value will be entered into the field.