County Level COVID-19 Risk Metrics

IDPH is monitoring several indicators that measure the health burden of COVID-19 in each Illinois county and capture a county’s ability to respond.  Many of these county-level indicators are similar to the Restore Illinois criteria and support that larger framework. These metrics are intended to be used for local level awareness of each county’s progress during Phase 4 and will help local leaders, businesses, local health departments, and the public make informed decisions and promote healthy behaviors.

The county level metrics are presented as weekly values, based on Sunday to Saturday of the week prior to the update. Each metric is individually compared to a target value or expected trend over two consecutive weeks to evaluate the status of COVID-19 disease burden or resource capacity for timely awareness. The measures are evaluated collectively to determine if multiple indicators are at warning levels. By applying the same metrics to each county, IDPH is using a standardized approach to monitor the state as a whole. Each county will be assessed to determine whether it is meeting or exceeding each indicator target. Counties meeting set targets will be indicated in blue, while counties that are not meeting the targets will be indicated in orange.

How to use these data

Individuals, families, and community groups can use these critical data to help inform their choices about personal and family gatherings, as well as what activities they choose to do.

  • Blue indicates that the county is experiencing overall stable COVID-19 metrics.  
  • Orange indicates there are warning signs of increased COVID-19 risk in the county. 

For example, if the local area is currently orange, some questions you should consider include: Should I still attend or host a large gathering? Are there additional precautions I should take given my personal/family health risks?  Should I wait to dine out or go to a movie?

During Phase 4, IDPH reminds everyone to wash their hands, wear a face covering, and watch their distance.

This page shows the status of public health indicators for each Illinois county.  

Data is provisional.

Select County: 

 

Week ##: ##/##/#### Through ##/##/####

New Cases Per 100,000

Case rate reported Sun-Sat
(Target: less than 50 per 100,000)


 

check_circle Target

Number of Deaths

Death number reported Sun-Sat
(Target: decreasing or stable Sun-Sat)


 

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Test Positivity (%)

(%) positive tests reported Sun-Sat
(Target: less than or equal to 10%)


 

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Tests Performed

Number of tests reported Sun-Sat
Target: Testing is Sufficient when test positivity is less than or equal to 10%


 

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CLI ED Visits (%), Adults

Emergency Department visits for COVID-19-like illness
(Target: decreasing or stable Sun-Sat)


 

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Number of CLI Admissions

Hospital admissions for COVID-19-like illness
(Target: decreasing or stable Sun-Sat)


 

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Cluster (%) of cases

No Target
This metric helps explain large increase in cases


 

ICU (%) Available

ICU bed availability
(Target: at least 20% of ICU beds available)


 

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Data Values
County New Cases per 100,000 Test Positivity % (%) CLI ED Visits, Adults Number of CLI Admissions Number of Deaths ICU (%) Available
Data Methodology

All metrics will be updated weekly, based on the previous week (i.e., previous Sunday through Saturday).

New cases per 100,000 people

This metric looks at the number of recent COVID-19 cases per 100,000 people to describe the potential number of people who are currently ill and may be infectious. This is the number of new cases reported to IDPH in the previous week.

Calculated as a rate = [County case count for 7 days] / [County population] x100,000

If there are fewer than 10 new cases for 7 days, the rate is not calculated and the exact count is used, due to instability in the rate.

  • Target:  Cases for the week are fewer than 10 or the rate is fewer than 50 cases per 100,000 people
  • Warning: New case rate is greater than 50 cases per 100,000 people

Test Positivity

The testing data represents data reported to IDPH through Electronic Laboratory Reporting (ELR) only.  It is based on the date results are reported into the ELR. It excludes testing data that are received from sites that have not implemented ELR. This excludes 3-5% of test data as of May 1, 2020.

Weekly test positivity = [County positive tests for 7 days] / [County total tests for same 7 days] x 100

  • Target: At or under 10% test positivity rate 
  • Warning: Above 10% test positivity rate

Tests Performed

The number of tests performed and reported through Electronic Laboratory Reporting (ELR) is presented only for context and increased awareness of testing resources, but is not a metric that is used to trigger a county warning.

Test positivity at or under 10% indicates there is sufficient testing. If the test positivity exceeds 10%, then the number of tests is considered insufficient.

Weekly Percent COVID-Like Illness Emergency Department Visits

Emergency department (ED) visits for COVID-Like Illness (CLI) are collected in near-real time using the Illinois Syndromic Surveillance System for hospitals, which looks at the reason an individual visits an emergency department and diagnosis. Visits are defined as CLI if the patient presents with a fever AND either cough, difficulty breathing or is given a diagnosis of COVID-19.

Percent of weekly CLI ED visits = [County CLI ED visits in adults ages 18 years and older for 7 days] / [County total ED visits in adults ages 18 years and older for same 7 days] x 100

County-level visits are measured by where the patient lives and the date they visited the emergency department.

  • Target: Decreasing or stable weekly percent of CLI ED visits (does not increase by more than 20% in a consecutive 2-week period)
  • Warning: Weekly percent of CLI ED visits increases for 2 consecutive weeks by more than 20%

Weekly Count of COVID-Like Illness Hospital Admissions

The weekly count of COVID-like Illness (CLI) hospital admissions is measured using the Illinois Syndromic Surveillance System.

Weekly number of CLI hospital admission = total number of CLI admissions for 7 days

  • Target: Decreasing or stable weekly number of CLI hospital admissions (number of CLI admissions does not increase by more than 20%)
  • Warning: Weekly number of CLI admissions is increasing for 2 consecutive weeks by more than 20%

Number of Deaths

The number of deaths is obtained by looking at the number of deaths with COVID infection as the underlying cause of death or the contributing cause of death, confirmed either by investigations or record match with the Illinois Vital Records data.

  • Target: Decreasing or stable number of deaths reported for 7 days (number of deaths does not increase by more than 20% in a consecutive 2-week period)
  • Warning: Number of deaths reported for 7 days increasing by more than 20% for 2 consecutive weeks.

Clusters – Percent of Cases Associated with a Cluster

Cases of COVID-19 are reported to the Illinois Electronic Disease Surveillance System (I-NEDSS). Cases that are linked to a cluster are identified using an outbreak ID number.

Percent of COVID-19 cases associated with a cluster = [Cases with outbreak ID occurring within 7 days] / [total cases occurring within the same 7 days] x 100

This metric is used for context to understand large increases in cases. It is also an indicator of successful investigation of cases to a known source. This is not a metric that is used to trigger a county warning.

ICU Percent Availability

Intensive Care Unit (ICU) availability is reported daily by each hospital and represents the number of ICU hospital beds that are empty. Hospitals are assigned to one of 11 Emergency Medical Services (EMS) regions. A county’s ICU percent will be the same value as the EMS Region in which the county is located. Hospital resources are shared across counties within an EMS Region. Some counties do not have hospitals, while some have only one or only have hospitals without ICU beds. For each EMS region, the weekly sum of the available ICU beds is divided by the sum of the total ICU beds (i.e., bed capacity) over the same period.

Weekly ICU availability = [Sum of ICU beds available in the region for 7 days] / [Total ICU beds in the region for 7 days] x 100

  • Target: At least 20% of ICU beds are available
  • Warning: Less than 20% of ICU beds are available