Score and Methodology
Where does the data come from?
In order to create the most accurate, timely, and local understanding of illness risk, we combine the best available datasets for each of four common infectious illnesses: COVID-19, flu, stomach bug (gastrointestinal illness), and common colds & other illnesses (e.g. RSV, rhinovirus, and enterovirus). The specific sources we use for each illness category are described in the table below.
How is the risk calculated?
Risk level (low, moderate, high, or critical)
Individual risk levels
Using the data sources in the table above, we evaluate the risk level of each illness based on:
The severity of the illness
Any established public health guidance (e.g. the CDC’s COVID-19 Community Levels). For example, it takes a much higher incidence of colds and other illnesses to reach a ‘critical’ level than it does for COVID-19 or flu
The historical illness trends (for example, what level of illness is "normal" for a given time of year, and whether it is currently higher or lower than expected)
Overall risk level
The overall risk level is calculated based on a combination of the individual illness risk levels, with a higher weight given to COVID-19 and flu because they tend to cause more severe health outcomes than the other illnesses:
Example 1: When COVID-19 or flu risk is elevated, the overall risk level will match whichever is highest
Example 2: When both COVID-19 and flu are High, the overall risk level is raised to Critical, reflecting the increased odds of catching an illness
Example 3: When the stomach bug or colds & other illnesses risk is Critical, the overall risk level will be High because these illnesses are typically less severe
Numeric risk score (1 to 100)
Individual risk scores
Numeric scores (1 to 100) are used to compare different units of measurement (case count, percent ill, percent positive tests) on the same risk scale. The following charts show the relationship between scores, illness levels, and units of measurement.
Note: because Stomach Bug and Colds and Other Illnesses tend to be less severe than COVID-19 and Flu, they are capped at a score of 75 so that they weigh less in the overall score calculation.
Overall risk score
The overall illness risk score is determined by the highest of the individual risk scores for COVID-19, flu, stomach bug, and colds and other illnesses.
How often is the data updated?
Kinsa data is updated daily. However, states only report flu data once a week, so the flu data is updated as available. To smooth out daily fluctuations, we calculate COVID-19, flu, and stomach bug illness levels using a 7-day rolling average or rolling sum of the data. Because colds can vary more from day to day, we use a 14-day rolling average to calculate the percent of Kinsa users with colds or other illnesses.
Suggested behaviors for each risk level
(1-24) Low Risk
Even when illness is low, keep your distance from anyone who's sick and keep your hands washed. Other than that, proceed as usual.
(25-49) Moderate Risk
Remain diligent with disinfecting frequently-touched surfaces and keep your distance from anyone who's showing signs of illness. If you're immunocompromised, wear a mask indoors.
(50-74) High Risk
Wear a quality face mask (ex. N95, KN95) indoors. If you're immunocompromised, avoid crowds and unnecessary indoor gatherings.
(75-100) Critical Risk
Indoor gatherings carry critical risk of illness transmission. If you must gather indoors, mask and make sure there’s ventilation. Skip the event to completely minimize your risk.
COVID-19 hospitalizations per 100k represents more severe illness than cases alone. Therefore, hospitalizations may not reflect rises in mild COVID-19 illness. Kinsa is currently updating methods and in the future will use at-home testing rates to estimate COVID-19 cases more accurately.
Colds and other illnesses are calculated using Kinsa’s symptomatic data. Because Kinsa does not rely on laboratory-confirmed tests, the cause of illness cannot be confirmed. Any fever-causing illness, even if it is not caused by a common cold, could be included in the colds category.
Counties with low populations may include data from nearby areas to improve data accuracy for flu, colds, and stomach bug estimates. We are not currently able to provide accurate estimates for regions smaller than counties. Because Kinsa does not have users in every zip code, we are unable to estimate illness for specific zip codes. Similarly, health departments do not provide COVID-19 or flu data for regions smaller than counties.
Still have more questions?
We would love to hear from you! For further questions or suggestions, please reach out to us at [email protected].