COVID-19 Calculator provides a set of scoring algorithms for evaluating COVID-19 symptoms implemented in TypeScript. The algorithms and associated inputs in this model are based on United States Department of Defense medical opinion and are actively used in MySymptoms.mil.

This calculator is currently maintained by Defense Digital Service (DDS).

NPM:

npm install @deptofdefense/covid19-calculator

Yarn:

yarn add @deptofdefense/covid19-calculator

Importing from the base will import the latest version.

ES6:

import { ages, conditions, symptoms, /*...*/ calculate } from '@deptofdefense/covid19-calculator'

CommonJS:

const { ages, conditions, symptoms, /*...*/ calculate } = require('@deptofdefense/covid19-calculator')

If you are interested in importing a previous version simply append the version. Each version functions as an independent package and thus the exports and TypeScript types may be different between versions.

ES6:

import { v1_3_0 } from '@deptofdefense/covid19-calculator'
const { ages, conditions, symptoms, /*...*/ calculate } = v1_3_0

CommonJS:

const { v1_3_0 } = require('@deptofdefense/covid19-calculator')
const { ages, conditions, symptoms, /*...*/ calculate } = v1_3_0

The following functions are exported. A category is a string in the exported list categories, i.e., likelihood, exposure, or preExisting. A score is an integer [0, N) with the maximum number changing depending on the model version. A level is a human-readable string the indicates the magnitude of the score, e.g., low, medium, or high.

NOTE: At this time, consider this api in "beta" with the possibility of changing slightly in future releases.

import { calculate, calculateScores, calculateLevel, calculateLevels } from '@deptofdefense/covid19-calculator'
// calculate returns the integer scores and string levels
const { scores, levels } = calculate({ ... })
// calculateScores just returns the integer scores
const { likelihoodScore, exposureScore, preExistingScore } = calculateScores({
  symptoms: [...],
  conditions: [...]
})
// calculateLevels returns the string levels for the given scores
const { likelihoodLevel, exposureLevel, preExistingLevel } = calculateLevels({
  likelihoodScore,
  exposureScore,
  preExistingScore
})
// calculateLevel returns the string level for the given score
const { likelihoodLevel } = calculateLevel('likelihood', 30)

If you need to correlate incoming data with calculator parameters, consider using a hashing algorithm to resolve parameters. See the advanced example for more info.

For the full list of examples see the examples folder.

const { calculate } = require('@deptofdefense/covid19-calculator');

const result = calculate({
  symptoms: ['fever', 'lossOfSmell'],
  conditions: ['hardBreathing'],
});
/*
 * result
 * {
 *   scores: { likelihood: 20, exposure: 0, preExisting: 0 },
 *   levels: { likelihood: 'low', exposure: 'low', preExisting: 'low' }
 * }
 */

• What's your age (in years)?
  • 0-17 - preExisting: 0
  • 18-39 - preExisting: 0
  • 40-64 - preExisting: 0
  • 65-69 - preExisting: 10
  • 70-79 - preExisting: 15
  • 80-Infinity - preExisting: 20

• In the last 14 days, did you have close contact with someone with symptoms of COVID-19 or diagnosed with COVID-19?
  • contact - Yes - exposure: 30
  • possibleContact - I Don't Know - exposure: 10
  • noContact - No - exposure: 0

• Select your current symptoms:
  • cough - Cough - likelihood: 20
  • sob - Shortness of breath - likelihood: 20
  • fever - Fever - likelihood: 20
  • bodyAches - Body aches or muscle pain - likelihood: 10
  • headache - Headache - likelihood: 10
  • throat - Sore throat - likelihood: 10
  • chills - Chills or repeated shaking with chills - likelihood: 10
  • lossOfSmell - New loss of taste or smell - likelihood: 20
  • vomiting - Nausea or vomiting (aliases: Vomiting) - likelihood: 5
  • dizziness - Dizziness or lightheadedness - likelihood: 5
  • diarrhea - Diarrhea - likelihood: 5
  • fatigue - Fatigue - likelihood: 5
  • congestion - Congestion or runny nose - likelihood: 5

• Select current conditions:
  • arouse - Disoriented or inability to wake/stay awake (worse than sleepy) (aliases: 'New confusion or inability to arouse', 'Confusion or inability to wake / stay awake') - likelihood: 40
  • hardBreathing - Trouble or difficulty breathing - likelihood: 40
  • chestPain - Persistent pain or pressure in the chest - likelihood: 40
  • blueLips - Bluish lips or face - likelihood: 40

• Select pre-existing conditions:
  • diabetesType2 - Type 2 diabetes mellitus - preExisting: 20
  • heartDisease - Heart conditions, such as heart failure, coronary artery disease, or cardiomyopathies - preExisting: 20
  • cancer - Cancer - preExisting: 20
  • kidneyDisease - Chronic kidney disease - preExisting: 20
  • copd - COPD - preExisting: 20
  • organTransplant - Had a solid organ transplant - preExisting: 20
  • sickleCellDisease - Sickle cell disease - preExisting: 20
  • overweight - Very overweight (Body Mass Index (BMI) of 30 or higher) - preExisting: 20
  • asthma - Asthma - preExisting: 15
  • smoke - Currently smoking - preExisting: 15
  • steroids - Take corticosteroids or other immunosuppressive medications - preExisting: 15
  • pregnant - Pregnant - preExisting: 15
  • cerebrovascular - Cerebrovascular disease - preExisting: 15
  • hypertension - Hypertension - preExisting: 15
  • diabetesType1 - Type 1 diabetes - preExisting: 10
  • lungDisease - Cystic fibrosis, emphysema, or other chronic lung diseases - preExisting: 10
  • thalassemia - Thalassemia - preExisting: 10
  • neurologicCondition - Neurologic conditions - preExisting: 10
  • liverDisease - Liver disease - preExisting: 10
  • compromisedImmuneSystem - Compromised immune system - preExisting: 10
  • hiv - HIV - preExisting: 10
  • boneMarrowTransplant - Had a bone marrow transplant - preExisting: 10

• veryLow: 0 - 9
• low: 10 - 19
• medium: 20 - 39
• high: 40 - 69
• veryHigh: 70+

• low: 0 - 9
• medium: 10 - 29
• high: 30+

• low: 0 - 9
• medium: 10 - 29
• high: 30+

This project was bootstrapped with TSDX. Below is a list of commands you will probably find useful.

Runs the project in development/watch mode. Your project will be rebuilt upon changes. TSDX has a special logger for you convenience. Error messages are pretty printed and formatted for compatibility VS Code's Problems tab. Your library will be rebuilt if you make edits.

Bundles the package to the dist folder. The package is optimized and bundled with Rollup into multiple formats (CommonJS, UMD, and ES Module).

Runs the test watcher (Jest) in an interactive mode. By default, runs tests related to files changed since the last commit.

We'd love to have your contributions! Please see CONTRIBUTING.md for more info.

Please see SECURITY.md for more info.

This project constitutes a work of the United States Government and is not subject to domestic copyright protection under 17 USC § 105. However, because the project utilizes code licensed from contributors and other third parties, it therefore is licensed under the MIT License. See LICENSE file for more information.