Domain | Factors | Description | |

1 | Socioeconomic vulnerability* | Below poverty level* | Calculated as the proportion of households at 0%–99% federal poverty level |

Unemployed* | Calculated as the proportion of households with both respondent and spouse (if present) unemployed | ||

No high school diploma* | Calculated as the proportion of respondents with less than a high school diploma | ||

2 | Demographic vulnerability and disability* | Aged 65 or older* | Calculated as the proportion of respondents aged 65 or older |

Single-parent household* | Calculated as the proportion of single-parent households with children under 18 years old | ||

Psychological disability† | Calculated as the proportion of respondents with a score of 13 or above on the Kessler Psychological Distress Scale | ||

3 | Minority status and language barriers* | Minority* | Calculated as the proportion of non-white race or Hispanic ethnicity respondents |

Non-English speaker* | Calculated as the proportion of respondents who speak English ‘not well’ or ‘not at all’ | ||

4 | High housing density* | Multiunit structures/mobile homes* | Calculated as the proportion of respondents who live in a multifamily or mobile house |

Urbanisation‡ | Calculated as the proportion of respondents who live in an urban or metropolitan area | ||

Extended household† | Calculated as the proportion of households with three or more adults | ||

5 | Epidemiological risk factors§ | High blood pressure§ | Calculated as the proportion of respondents with ever physician-diagnosed high blood pressure |

Heart disease§ | Calculated as the proportion of respondents with ever physician-diagnosed heart disease | ||

Asthma§ | Calculated as the proportion of respondents who reported currently having asthma | ||

Smoking§ | Calculated as the proportion of respondents who reported being a current or former smoker | ||

Obesity§ | Calculated as the proportion of respondents with a BMI of 30 or more for non-Asians or 27 or more for Asians | ||

Diabetes§ | Calculated as the proportion of respondents with ever physician-diagnosed diabetes | ||

Healthcare occupation† | Calculated as the proportion of respondents with an occupation in healthcare delivery | ||

High-risk occupation† | Calculated as the proportion of respondents in essential occupations that have high risk of exposure to infectious diseases | ||

6 | Low access to healthcare‡ | No health insurance† | Calculated as the proportion of respondents who reported having no health insurance in the past 12 months |

No usual source of healthcare† | Calculated as the proportion of respondents who reported no usual source of healthcare (ie, doctor’s office, community or government clinic, community hospital) |

*Adapted from Centers for Disease Control and Prevention (CDC) Social Vulnerability Index (SVI).

†Author included.

‡Adapted from Acharya and Porwal.45

§Adapted from Surgo Foundation’s COVID-19 Community Vulnerability Index (CCVI).

BMI, body mass index.