Overview
Throughout Marketscape Insights you will find some counts and performance metrics that do not include actual numbers. This article explains the alternative entries.
<11
Our data is derived from the CMS Virtual Research Data Center. In order to maintain the levels of patient confidentiality required by CMS, all counts and percentages that could reveal a patient count less than 11 will be indicated by <11 in that cell in the table.
- For counts, <11 is used for any patient count less than eleven (11).
- For percentages, this would represent any instances where the calculation includes a patient count that is less that eleven (11) in the denominator. In these cases, the percentage is replaced with "ins." See below.
ins
"ins" has three different uses
- Insufficient - In cases where there is insufficient data to make a meaningful calculation. The most common example is when we would normally calculate a performance metric based on a patient count, but the patient count is <11. There is no way to calculate when there are numbers missing in the equation.
- Insignificant - sometimes when we calculate a performance metric, the result is so small that it has no meaning. For example, a readmission rate of 0.00005% has no meaning so we won't show it.
- Suppressed - Sometimes the data displayed in a table could be combined together and used to calculate an actual patient count <11. When this occurs, we suppress a number in the table. Look at the following example of patient counts:
Annual | Q1 | Q2 | Q3 | Q4 | |
Patient Counts | 60 | 21 | 20 | 17 | <11 |
Some basic math skills will reveal that 60 = 21 + 20 + 17 + X, where X is 2.
What we would do in this case is:
Annual | Q1 | Q2 | Q3 | Q4 | |
Patient Counts | 60 | 21 | 20 | ins | <11 |
Now you can't calculate the Q4 patient count.
See Statistical Significance for Solution Display.
Hyphen, “-“
A hyphen is a null - it means that no metric was calculated for the cell.
Zero (0)
Zero is used when a metric is calculated and the count is zero or the percent is zero %.
It is important to distinguish between "-" and 0. If a table cell contains "-" this means that we did not calculate the metric. A zero is the result of a calculation that returned a result of zero or zero percent - 0%.
Statistical Significance for Solution Display
Calculated fields exist in Strategy and Marketscape Insights for which the denominator of the patient population is sometimes known, and sometimes unknown. Per CMS rules, no field can be displayed if the cell value is 10 or less. However, when calculating certain measures, Trella Health increases the limits on the patient denominator to ensure statistical significance. If the statistical significance threshold is not met, a value of “ins” is displayed to denote “insignificant” patient population.
Examples:
Average Length of Stay (ALOS)
Since ALOS is a metric calculated for a patient population that is solely within the confines of the agency to control, Trella Health displays this measure when the population of patients is >10 patients. Thus, if the number of patients is not <11, the ALOS will be displayed. Otherwise, “ins” is displayed.
Performance Metrics
Performance metrics are measures that typically involved another provider (e.g., hospitalizations and readmit rates). To ensure anomalies in the data are smoothed and a significant patient population is available, Trella creates these measures using a two-year population of patients. In this case, the threshold is 30 patients, otherwise “Ins” is displayed. This enables 30 patients for a denominator when creating two-year rates, and for one-year (rare) the threshold would be 15 patients. By calculating these rates in this way, we can display low rates by mandating a large denominator for the patient population, and calculating the measure over two years, ensuring the calculation cannot be applied to a patient count of one year.