Data-entry error results in hundreds of misclassified COVID-19 cases in Ada County

Posted at 9:57 PM, Mar 04, 2021
and last updated 2021-03-04 23:57:11-05

This article was originally published by Rachel Roberts in the Idaho Statesman.

Through Thursday, Central District Health was reporting 39,529 confirmed cases and 7,603 probable cases in Ada County. Health and Welfare, however, showed Ada County with 39,988 confirmed cases and 7,165 probable cases.

“We recently recognized a data-entry issue wherein some probable cases related to antigen test results were entered into the state’s system by CDH as confirmed,” district spokesperson Christine Myron wrote in an email to the Idaho Statesman. “We are working to reconcile this, and as we continue to do so, the confirmed cases on the state’s site will come down, and the number of probable cases will go up.

“This may take a couple of weeks to fully reconcile, but overall, we estimate the misclassification of some of these cases is less than 1% of total reported cases.”

Central District Health uses the NEDSS (National Electronic Disease Surveillance System) Base System, known as NBS, to report disease data to the Idaho Department of Health and Welfare, and that same system relays the state data to the Centers for Disease Control and Prevention. CDH does not use NBS for its own data records, which is why the confirmed and probable case numbers displayed by CDH for Ada County differ from those figures on the Health and Welfare website.

The incorrect classification did not affect the total number of cases (confirmed and probable) that have been reported for Ada County to date, officials said. Those figures remain similar between Health and Welfare (47,153) and CDH (47,132), and are dependent on the time of day the data is pulled.

“It’s a reminder that daily case counts do not depict the number of positive cases that actually occurred for that given day; instead, they are the number of labs that were made into cases on that given day at that point in the day that we post numbers — for (Central District Health), around 5 p.m.; for DHW, numbers are pulled around 1 p.m.,” Myron continued.

Because the misclassification affects the confirmed case total the Idaho Statesman has been using for its daily updates, the Statesman is unable to provide a daily county-by-county total for March 4. Our daily updates will return March 5, when we will begin using total case numbers instead of confirmed in our county-by-county breakdowns.

Central District Health also pointed out that while Health and Welfare showed an increase of 145 confirmed cases for Ada County on March 3, Central District Health reported 132 total cases (confirmed and probable combined) for the same day.

“What looks at face value like the largest increase in more than a month for Ada County, as was reported last night, is the result of a batch of about 200 cases being reported to CDH on Feb. 25 with collection dates that actually date back as early as Jan. 1,” Myron wrote. “It took our data-entry staff a few days to work through the data entry because the clinic reporting these results sent over a paper list of all positive results dating back to Jan. 1, and staff had to determine which had already been reported vs. which were new.”


The most recent COVID-19 test positivity rate update from the Idaho Department of Health and Welfare shows Idaho below the 5% threshold for the first time since June.

Health and Welfare reported a positivity rate of 4.5% on 24,040 tests for Feb. 21-27. That’s down slightly from a rate of 4.6% on 26,164 tests for Feb. 14-20.

Last week, the positivity rate for Feb. 14-20 was reported at 5.1% on 21,828 tests. But rates can change as additional test results are added by Health and Welfare.

The World Health Organization has advised governments that before reopening, rates of positivity should remain at 5% or lower for at least 14 days.

Of the state’s seven public health districts, four saw a decrease in positivity from the previous week. Southwest District Health, home to the cities of Nampa and Caldwell, and Boise-based Central District Health each had rates of 3.4%. Eastern Idaho Public Health had the highest rate, at 12.1%. The lowest rate in the state went to South Central Public Health District, at 3.1%.

Vaccine doses administered in Idaho: 406,866, according to Health and Welfare. Of those, 122,038 people have received only their first dose.

Overall hospitalizations: Health and Welfare reports that there have been 7,164 hospitalizations of people with COVID-19, 1,242 admissions to the ICU and 9,662 health care workers infected. Hospital and health care numbers are based on cases with completed investigations into contacts, not the full number of positives.

St. Luke’s Health System: As of March 3, the health system was reporting 20 patients in its hospitals with confirmed COVID-19 out of 465 patients overall. The health system reported a 14-day coronavirus test positivity rate of 4%.

Saint Alphonsus Health System: As of March 3, the health system was reporting 32 patients in its hospitals with confirmed COVID-19 out of 357 patients overall. The health system reported a 14-day coronavirus test positivity rate of 8.8%.

Boise School District: Reported confirmed cases since March 2: Borah High (3), Morley Nelson Elementary (1).

West Ada School District: Reported confirmed cases for Feb. 18-March 3: Eagle High (8), Mountain View High (1), Rocky Mountain High (3), Victory Middle (1), Barbara Morgan STEM Academy (1), Christine Donnell School of the Arts (1), Discovery Elementary (1), Peregrine Elementary (3), Prospect Elementary (1), River Valley Elementary (1).