March 4, 2020 to April 28, 2020
Variables affected:
-
positiveCasesViral
Tags: CTP Backfill CTP API / Logic Changes
We determined that California had always reported only Confirmed cases as their Total Cases, so we copied California's Total cases into Confirmed cases prior to April 29, 2020.
February 25, 2021
Variables affected:
-
death
Tags: State Anomalies State Data Note
On February 25, 2021, California announced that their deaths included a backlog of 806 deaths initially not reported as COVID019 deaths from Los Angeles County. As a result, many of the deaths reported on February 25, 2021 occurred between December 3, 2020 and February 3, 2021. We urge caution when interpreting numbers from this period, and encourage the use of 7 and 14-day averages as more reliable metrics than individual figures.
January 21, 2021
Variables affected:
-
hospitalizedCurrently -
inIcuCurrently
Tags: Other State Anomalies
On January 21st, 2021, the website reporting current hospitalization and icu bugged out and could not deliver numbers. We used the number on the official state website instead, which usually matches up with the numbers on the website
December 25, 2020
Variables affected:
-
All Metrics
Tags: State / Metric No Update
On December 25, 2020, Alaska, California, Connecticut, the District of Columbia, Idaho, Kansas, Louisiana, Massachusetts, Michigan, Minnesota, North Carolina, North Dakota, New Hampshire, Ohio, Rhode Island, South Carolina, South Dakota, Utah, and Vermont did not update their data due to the Christmas holiday.
December 16, 2020
Variables affected:
-
positiveCasesViral
Tags: State Data Note State Annotation / Source Change
On December 16, 2020, California [announced](https://www.cdph.ca.gov/Programs/OPA/Pages/NR20-338.aspx) that their cases for December 16, 2020 include 15,337 cases from previous days due to a change in case processing. It appears this new process will regularly include a higher volume of cases that were not identified within the previous 24 hours.
December 8, 2020
Variables affected:
-
hospitalizedCurrently -
inIcuCurrently
Tags: State Anomalies
On December 8, 2020, our regular source for Currently in ICU did not update properly today, so we updated Currently hospitalized and Currently in ICU numbers using the state page, as they've historically matched time series.
November 18, 2020
Variables affected:
-
hospitalizedCurrently -
inIcuCurrently
Tags: CTP Process / Source Change
On November 18, 2020, California's Hospitalization Tableau dashboard did not update, so we updated their Currently hospitalized and Currently in ICU numbers from the state dashboard instead.
November 8, 2020
Variables affected:
-
totalTestsViral -
positiveCasesViral -
death -
negative -
positive
Tags: CTP Backfill CTP Backfill Missed Update
On November 8, 2020 California updated after out publish time. Our data was updated from dashboards that evening.
October 23, 2020
Variables affected:
-
positive
On 10/23, CA reported a backlog of ~2000 cases, resulting in 6141 new cases for the day.
March 4, 2020
Variables affected:
-
totalTestsPeopleViral -
totalTestResults
Tags: CTP API / Logic Changes
As of September 18, 2020, California's total test results are drawn from our `totalTestsViral` field instead of calculated via positive+negative.
September 18, 2020
Variables affected:
-
totalTestResults
Tags: CTP API / Logic Changes CTP Backfill
Multiple states were switched to use direct columns
August 12, 2020 to August 13, 2020
Variables affected:
-
dataQualityGrade
States Grades not published for 8/12-8/13
August 11, 2020
Variables affected:
-
positiveCasesViral -
positive
On 8/11, a note on CA's state site read, "Note: Today’s case counts include backlogged cases that would have been reported in earlier days and weeks and are not an accurate representation of cases reported in the prior 24 hours."
August 10, 2020
Variables affected:
-
positive
On 8/10, CA site annotation read, "Note: The issue with the state’s electronic laboratory reporting system has been addressed and the system is now performing as expected. The entire backlog has been completely eliminated, and new cases attributed to the backlog will be reported over the next few days."
August 4, 2020
Variables affected:
-
totalTestsViral -
positiveTestsViral -
positiveCasesViral -
positive
(1) On 8/4, we noticed a discrepancy for Total PCR Tests on the dashboard. The update for 8/4 at the top of the state page reports 8,302,713 PCR tests, but the testing section of the dash reports 8,305,713. We went with 8,305,713. (2) On 8/4, CDPH discovered an underreporting of COVID-19 cases due to technology issues with the electronic laboratory reporting system which reports into the state’s disease registry system, leading to likely under-counts of single day cases at the state and local levels.
July 23, 2020 to July 28, 2020
Variables affected:
-
hospitalizedCurrently -
inIcuCurrently
On 7/23 California has reported that its current hospitalization and ICU numbers are incomplete due to its transition to the HHS reporting system, so we froze the values. On 7/28, we unfroze the values. We will backfill the complete numbers for July 23 - July 28 when reporting is back at 100%.
July 20, 2020
Variables affected:
-
recovered
Mistakenly entered Recovered number for 7/20 removed.
June 29, 2020 to July 5, 2020
Variables affected:
-
positive
From June 29 to July 5th, California made a few revisions to daily case numbers, on 7/17 we updated the values based on the most recent data from their dashboard.
July 8, 2020
Variables affected:
-
positive -
positiveCasesViral
Tags: State Anomalies
On July 8, 2020, California data included a backlog from Los Angeles County, which had not reported for several days. Approximately 1,000 of the 11,000 new cases were attributed to this backlog data.
April 22, 2020
Variables affected:
-
totalTestsViral
Tags: State Annotation / Source Change
Starting April 22, 2020, California is reporting specimens tested instead of people tested. This caused an increase of over 165,000 tests on April 22, 2020, because some people are tested more than once and more than one specimens per person may be tested.
April 4, 2020 to April 22, 2020
Variables affected:
-
negative
Tags: State Anomalies
On April 4 and April 22, 2020, California reported large batches of backlogged **negative test** data.
March 4, 2020 to April 1, 2020
Variables affected:
-
All Metrics
Tags: CTP Process / Source Change
Prior to April 1, 2020, The COVID Tracking Project used county data sources for more timely reporting of California's COVID-19 data. At the start of April, we switched to using the state dashboard. This led to a modest drop in positive and death as the state's data lagged behind the county sources.