15 Sep 2020
To calculate the first two metrics, we must know the number of Daily New Positive Test Results and New Daily Negative Test Results. Reporting of this data by the University of Tennessee, Knoxville (UTK) was acquired through a public records request. Latest testing data is not currently available, but is expected to be in the short future.
30 Aug Public records request is filed via e-mail.
8 Sep Received Public Record Request Response Form
11 Sep Received update saying, "We are continuing to work on your request. I will update you no later than Wednesday, Sept. 16."
15 Sep Received Public Records Response with testing data from Aug 9-30th, the following notes were attached:
The calculation of a positivity rate for Student Health Center tests should not be construed as representing overall infection rates across campus. The SHC conducts testing for all symptomatic students and asymptomatic students who are close contacts of a COVID-19 case.
The numbers only indicate the results of tests conducted in the SHC. Students may be tested at other healthcare facilities off-campus and, while we may informed of a positive result, complete testing data (tests performed, positives, and negatives) from off-campus sites is not provided to us. Additionally, the Student Health Center does not test employees.
There appears to be a data entry error in the dataset for Aug. 26 in which negative SHC tests are in the dataset, but not tests conducted.
15 Sep Received updated numbers for Sept 1-15th via request.
To get to a near zero case incidence level, UTK needs to first understand the severity of the outbreak they are responding to. The best available metric to measure the viral spread and the relative community risk is New Cases per 100,000 people. The Harvard Global Health Institute put forward a Key Metrics for COVID Suppression unified framework, and it uses this as the key metric (see the infographic below).
The following priorities for a TTSI program lead to the most efficient progress on the path to zero:
Priority 1: Test hotspots, using mobile-labs, walk-in, and drive thru clinics as well as testing of all staff and residents in congregate living facilities with outbreaks;
Priority 2: Encourage all symptomatics (regardless of severity of symptoms) to be tested (or to self-quarantine) and all those who have reason to think they have been exposed to the disease to come in for a test.
Priority 3: Trace the contacts of all covid-positive individuals throughout the population. Every covid-positive individual should generate 25 additional tests.
Mitigation and suppression goals are calculated based on the number of Daily New Cases per 100,000.
For each day, I calculate the ratio of New Positive Test Results to Daily New Test Results. For example, given:
## Daily New Positive Test Results (Cases)
10
## Daily New Test Results
200
## Test Positivity Rate
10 / 200 = 0.05 = 5%
I calculate 7-day simple moving averages for Daily New Test Results and Test Positivity Rate. Beginning with discrete data produced by inferring Daily New Test Results (by averaging over the reporting period), this establishes a continuous trendline that more closely resembles reality. The shorter the reporting period, the better this trendline reflects the actual 7-day average trend.
Mitigation and suppression goals are 10% and 3% respectively.
To effectively administer a contact tracing program, it is essential to quickly obtain test results for each person tested. The longer it takes to obtain test results, the more likely it is that additional chains of transmission occur. This data needs to be reported publicly in order for testing performance, and in turn the potential effectiveness of contact tracing, to be evaluated.