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Contingency Tables

This documentation describes the fine-resolution contingency tables produced by grouping COVID Symptom Survey individual responses by various demographic features:

These contingency tables provide demographic breakdowns of COVID-related topics such as vaccine uptake and acceptance. They are more detailed than the coarse aggregates reported in the COVIDcast Epidata API, which are grouped only by geographic region. Individual response data for the survey is available, but only to academic or nonprofit researchers who sign a Data Use Agreement, whereas these contingency tables are available to the general public.

Please see our survey credits and citation information for information on how to cite this data if you use it in a publication.

Important updates for data users, including corrections to data or updates on data processing delays, are posted as OUTAGES.txt in the directory where the data is hosted.

Table of contents

  1. Available Data Files
  2. Dates
  3. Aggregation
  4. File Format
    1. Naming
    2. Columns
  5. Indicators
    1. Symptoms
    2. Vaccine Uptake and Acceptance
    3. Outreach and Image
    4. Reasons for Hesitancy
    5. Reasons for Believing Vaccine is Unnecessary

Available Data Files

We provide two types of data files, weekly and monthly. Users who need the most up-to-date data or are interested in timeseries should use the weekly files, while those who want to study groups with smaller sample sizes should use the monthly files. Because monthly aggregates include more responses, they have lower missingness when grouping by several features at a time.

Dates

The included files provide estimates for various metrics of interest over a period of either a full epiweek (or MMWR week, a standardized numbering of weeks throughout the year) or a full calendar month.

Note: CSVs for the month of January 2021 only use data from January 6-31 due to a definitional change in a major vaccine item on January 6. Indicators based on item V9 use data starting January 12. CSVs for the week starting January 6, 2021, only use data from January 6-9 due to the same definitional change.

Aggregation

The aggregates are filtered to only include estimates for a particular group if that group includes 100 or more responses. Especially in the weekly aggregates, many of the state-level groups have been filtered out due to low sample size. In such cases, the state marginal files, which group by a single demographic of interest at a time, will likely provide more coverage.

File Format

Naming

Each CSV is named as follows:

{date}_{region}_{vars}.csv

Dates are of the form YYYYmmdd. date refers to the first day of the time period survey responses were aggregated over, in the Pacific time zone (UTC - 7). Unless noted otherwise, the time period is always a complete month or epiweek. region is the geographic level responses were aggregated over. At the moment, only nation-wide and state groupings are available. vars is a list all other grouping variables used in the aggregation, ordered alphabetically.

Columns

Within a CSV, the first few columns are the grouping variables, ordered alphabetically. Each aggregate reports four columns (unrounded):

  • val_<indicator name>: the main value of interest, e.g., percent, average, or count, estimated using the survey weights to better match state demographics
  • se_<indicator name>: the standard error of val_<indicator name>
  • sample_size_<indicator name>: the number of survey responses used to calculate val_<indicator name>
  • represented_<indicator name>: the number of people in the population that val_<indicator name> represents over all days in the given time period. This is the sum of survey weights for all survey responses used.

All aggregates using the same set of grouping variables appear in a single CSV. Grouping variables use prefixes to indicate the format of the column and the originating question.

  • b_ indicates a binary variable, coded as a boolean (True/False or 1/0). The originating item may be a yes/no question, or the variable may be a binary interpretation of a multiple choice or multi-select item.
  • mc_ indicates a multiple choice question, where the respondent is able to select no more than one response. For example, age in D2.
  • ms_ indicates a multi-select question, where the respondent is able to select more than one response if desired. For example, pre-existing medical conditions in C1.

Indicators

The files contain weighted estimates of the percent of respondents who fulfill one or several criteria. Estimates are broken out by state, age, gender, race, ethnicity, occupation, and health conditions.

Indicators beginning “hesitant_” (not listed) are variants of other described indicators calculated among respondents who say they would “probably not” or “definitely not” choose to get vaccinated, if offered today (item V3).

We plan to expand this list of indicators based on research needs; if you have a public health or research need for a particular variable not listed here, please contact us at delphi-survey-info@lists.andrew.cmu.edu.

Symptoms

Indicator Description Survey Item
pct_cli Estimated percentage of people with COVID-like illness, using the same definition as in the API
Earliest date available: 2021-01-01
A1 and A2
pct_ili Estimated percentage of people with influenza-like illness, using the same definition as in the API
Earliest date available: 2021-01-01
A1 and A2
pct_hh_cmnty_cli Estimated percentage of people reporting illness in their local community, including their household, using the same definition as in the API
Earliest date available: 2021-01-01
A1, A2, and A4
pct_anosmia Estimated percentage of people experiencing loss of smell or taste in the last 24 hours.
Earliest date available: 2021-01-01
A2

Vaccine Uptake and Acceptance

Indicator Description Survey Item
pct_vaccinated Estimated percentage of respondents who have already received a COVID vaccine.
Earliest date available: 2021-01-01
V1
pct_received_2_vaccine_doses Estimated percentage of respondents who have received two doses of a COVID-19 vaccine, among respondents who have received either one or two doses of a COVID-19 vaccine.
Earliest date available: 2021-01-01
V2
pct_vaccinated_or_accept Estimated percentage of respondents who either have already received a COVID vaccine or would definitely or probably choose to get vaccinated, if a vaccine were offered to them today.
Earliest date available: 2021-01-01
V1 and V3
pct_accept_vaccine Estimated percentage of respondents who would definitely or probably choose to get vaccinated, if a vaccine were offered to them today, among respondents who have not yet been vaccinated.
Earliest date available: 2021-01-01
V3
pct_hesitant_vaccine Estimated percentage of respondents who would definitely not or probably not choose to get vaccinated, if a vaccine were offered to them today, among respondents who have not yet been vaccinated.
Earliest date available: 2021-01-01
V3
pct_accept_vaccine_defyes Estimated percentage of respondents who would definitely choose to get vaccinated, if a vaccine were offered to them today, among respondents who have not yet been vaccinated.
Earliest date available: 2021-01-01
V3
pct_accept_vaccine_probyes Estimated percentage of respondents who would probably choose to get vaccinated, if a vaccine were offered to them today, among respondents who have not yet been vaccinated.
Earliest date available: 2021-01-01
V3
pct_accept_vaccine_probno Estimated percentage of respondents who would probably not choose to get vaccinated, if a vaccine were offered to them today, among respondents who have not yet been vaccinated.
Earliest date available: 2021-01-01
V3
pct_accept_vaccine_defno Estimated percentage of respondents who would definitely not choose to get vaccinated, if a vaccine were offered to them today, among respondents who have not yet been vaccinated.
Earliest date available: 2021-01-01
V3

Outreach and Image

Indicator Description Survey Item
pct_vaccine_likely_friends (formerly pct_trust_fam) Estimated percentage of respondents who would be more likely to get a COVID-19 vaccine if it were recommended to them by friends and family, among respondents who have not yet been vaccinated.
Earliest date available: 2021-01-01
V4
pct_vaccine_likely_who (formerly pct_trust_who) Estimated percentage of respondents who would be more likely to get a COVID-19 vaccine if it were recommended to them by the World Health Organization, among respondents who have not yet been vaccinated.
Earliest date available: 2021-01-01
V4
pct_vaccine_likely_govt_health (formerly pct_trust_govt) Estimated percentage of respondents who would be more likely to get a COVID-19 vaccine if it were recommended to them by government health officials, among respondents who have not yet been vaccinated.
Earliest date available: 2021-01-01
V4
pct_vaccine_likely_politicians (formerly pct_trust_politicians) Estimated percentage of respondents who would be more likely to get a COVID-19 vaccine if it were recommended to them by politicians, among respondents who have not yet been vaccinated.
Earliest date available: 2021-01-01
V4
pct_vaccine_likely_doctors Estimated percentage of respondents who would be more likely to get a COVID-19 vaccine if it were recommended to them by doctors and other health professionals they go to for medical care, among respondents who have not yet been vaccinated. This item was shown to respondents starting in Wave 8.
Earliest date available: 2021-02-08
V4
pct_vaccine_likely_local_health (formerly pct_trust_healthcare) Discontinued as of Wave 8, Feb 8, 2021 Estimated percentage of respondents who would be more likely to get a COVID-19 vaccine if it were recommended to them by local health workers, among respondents who have not yet been vaccinated.
Earliest date available: 2021-01-01
V4

Reasons for Hesitancy

Indicator Description Survey Item
pct_worried_vaccine_sideeffects (formerly pct_concerned_sideeffects) Estimated percentage of respondents who are very or moderately concerned that they would “experience a side effect from a COVID-19 vaccination.” (Asked of all respondents, including those who have already received one or more doses of a COVID-19 vaccine.)
Earliest date available: 2021-01-01
V9
pct_barrier_sideeffects Estimated percentage of respondents who say they are hesitant to get vaccinated because they are worried about side effects, among respondents who answered “Yes, probably”, “No, probably not”, or “No, definitely not” when asked if they would get vaccinated if offered (item V3). This series of items was shown to respondents starting in Wave 8.
Earliest date available: 2021-02-08
V5abc
pct_barrier_allergic Estimated percentage of respondents who say they are hesitant to get vaccinated because they are worried about having an allergic reaction, among respondents who answered “Yes, probably”, “No, probably not”, or “No, definitely not” when asked if they would get vaccinated if offered (item V3). This series of items was shown to respondents starting in Wave 8.
Earliest date available: 2021-02-08
V5abc
pct_barrier_ineffective Estimated percentage of respondents who say they are hesitant to get vaccinated because they don’t know if a COVID-19 vaccine will work, among respondents who answered “Yes, probably”, “No, probably not”, or “No, definitely not” when asked if they would get vaccinated if offered (item V3). This series of items was shown to respondents starting in Wave 8.
Earliest date available: 2021-02-08
V5abc
pct_barrier_dontneed Estimated percentage of respondents who say they are hesitant to get vaccinated because they don’t believe they need a COVID-19 vaccine, among respondents who answered “Yes, probably”, “No, probably not”, or “No, definitely not” when asked if they would get vaccinated if offered (item V3). This series of items was shown to respondents starting in Wave 8.
Earliest date available: 2021-02-08
V5abc
pct_barrier_dislike_vaccines Estimated percentage of respondents who say they are hesitant to get vaccinated because they dislike vaccines, among respondents who answered “Yes, probably”, “No, probably not”, or “No, definitely not” when asked if they would get vaccinated if offered (item V3). This series of items was shown to respondents starting in Wave 8.
Earliest date available: 2021-02-08
V5abc
pct_barrier_not_recommended Estimated percentage of respondents who say they are hesitant to get vaccinated because their doctor did not recommend it, among respondents who answered “Yes, probably”, “No, probably not”, or “No, definitely not” when asked if they would get vaccinated if offered (item V3). This series of items was shown to respondents starting in Wave 8.
Earliest date available: 2021-02-08
V5abc
pct_barrier_wait_safety Estimated percentage of respondents who say they are hesitant to get vaccinated because they want to wait to see if the COVID-19 vaccines are safe, among respondents who answered “Yes, probably”, “No, probably not”, or “No, definitely not” when asked if they would get vaccinated if offered (item V3). This series of items was shown to respondents starting in Wave 8.
Earliest date available: 2021-02-08
V5abc
pct_barrier_low_priority Estimated percentage of respondents who say they are hesitant to get vaccinated because they think other people need it more than they do, among respondents who answered “Yes, probably”, “No, probably not”, or “No, definitely not” when asked if they would get vaccinated if offered (item V3). This series of items was shown to respondents starting in Wave 8.
Earliest date available: 2021-02-08
V5abc
pct_barrier_cost Estimated percentage of respondents who say they are hesitant to get vaccinated because they are worried about the cost, among respondents who answered “Yes, probably”, “No, probably not”, or “No, definitely not” when asked if they would get vaccinated if offered (item V3). This series of items was shown to respondents starting in Wave 8.
Earliest date available: 2021-02-08
V5abc
pct_barrier_distrust_vaccines Estimated percentage of respondents who say they are hesitant to get vaccinated because they don’t trust COVID-19 vaccines, among respondents who answered “Yes, probably”, “No, probably not”, or “No, definitely not” when asked if they would get vaccinated if offered (item V3). This series of items was shown to respondents starting in Wave 8.
Earliest date available: 2021-02-08
V5abc
pct_barrier_distrust_govt Estimated percentage of respondents who say they are hesitant to get vaccinated because they don’t trust the government, among respondents who answered “Yes, probably”, “No, probably not”, or “No, definitely not” when asked if they would get vaccinated if offered (item V3). This series of items was shown to respondents starting in Wave 8.
Earliest date available: 2021-02-08
V5abc
pct_barrier_health_condition Estimated percentage of respondents who say they are hesitant to get vaccinated because they have a health condition that may impact the safety of a COVID-19 vaccine, among respondents who answered “Yes, probably”, “No, probably not”, or “No, definitely not” when asked if they would get vaccinated if offered (item V3). This series of items was shown to respondents starting in Wave 8.
Earliest date available: 2021-02-08
V5abc
pct_barrier_pregnant Estimated percentage of respondents who say they are hesitant to get vaccinated because they are pregnant or breastfeeding, among respondents who answered “Yes, probably”, “No, probably not”, or “No, definitely not” when asked if they would get vaccinated if offered (item V3). This series of items was shown to respondents starting in Wave 8.
Earliest date available: 2021-02-08
V5abc
pct_barrier_religious Estimated percentage of respondents who say they are hesitant to get vaccinated because it is against their religious beliefs, among respondents who answered “Yes, probably”, “No, probably not”, or “No, definitely not” when asked if they would get vaccinated if offered (item V3). This series of items was shown to respondents starting in Wave 8.
Earliest date available: 2021-02-08
V5abc
pct_barrier_other Estimated percentage of respondents who say they are hesitant to get vaccinated for another reason, among respondents who answered “Yes, probably”, “No, probably not”, or “No, definitely not” when asked if they would get vaccinated if offered (item V3). This series of items was shown to respondents starting in Wave 8.
Earliest date available: 2021-02-08
V5abc

The set of “barrier” items correspond to the set of “hesitancy_reasons” items in the API.

Reasons for Believing Vaccine is Unnecessary

Respondents who indicate that “I don’t believe I need a COVID-19 vaccine” (in items V5a, V5b, V5c, or V5d) are asked a follow-up item asking why they don’t believe they need the vaccine. These signals summarize the reasons selected. Respondents who do not select any reason (including “Other”) are treated as missing.

This item was shown to respondents starting in Wave 8.

Indicator Description Survey Item
pct_hesitant_dontneed_reason_had_covid Estimated percentage of respondents who say they don’t need to get a COVID-19 vaccine because they already had the illness, among respondents who answered “No, probably not” or “No, definitely not” when asked if they would get vaccinated if offered (item V3) and provided at least one reason for why they believe a COVID-19 vaccine is unnecessary.
Earliest date available: 2021-02-08
V6 and V5bc
pct_hesitant_dontneed_reason_dont_spend_time Estimated percentage of respondents who say they don’t need to get a COVID-19 vaccine because they don’t spend time with high-risk people, among respondents who answered “No, probably not” or “No, definitely not” when asked if they would get vaccinated if offered (item V3) and provided at least one reason for why they believe a COVID-19 vaccine is unnecessary.
Earliest date available: 2021-02-08
V6 and V5bc
pct_hesitant_dontneed_reason_not_high_risk Estimated percentage of respondents who say they don’t need to get a COVID-19 vaccine because they are not in a high-risk group, among respondents who answered “No, probably not” or “No, definitely not” when asked if they would get vaccinated if offered (item V3) and provided at least one reason for why they believe a COVID-19 vaccine is unnecessary.
Earliest date available: 2021-02-08
V6 and V5bc
pct_hesitant_dontneed_reason_precautions Estimated percentage of respondents who say they don’t need to get a COVID-19 vaccine because they will use other precautions, such as a mask, instead, among respondents who answered “No, probably not” or “No, definitely not” when asked if they would get vaccinated if offered (item V3) and provided at least one reason for why they believe a COVID-19 vaccine is unnecessary.
Earliest date available: 2021-02-08
V6 and V5bc
pct_hesitant_dontneed_reason_not_serious Estimated percentage of respondents who say they don’t need to get a COVID-19 vaccine because they don’t believe COVID-19 is a serious illness, among respondents who answered “No, probably not” or “No, definitely not” when asked if they would get vaccinated if offered (item V3) and provided at least one reason for why they believe a COVID-19 vaccine is unnecessary.
Earliest date available: 2021-02-08
V6 and V5bc
pct_hesitant_dontneed_reason_not_beneficial Estimated percentage of respondents who say they don’t need to get a COVID-19 vaccine because they don’t think vaccines are beneficial, among respondents who answered “No, probably not” or “No, definitely not” when asked if they would get vaccinated if offered (item V3) and provided at least one reason for why they believe a COVID-19 vaccine is unnecessary.
Earliest date available: 2021-02-08
V6 and V5bc
pct_hesitant_dontneed_reason_other Estimated percentage of respondents who say they don’t need to get a COVID-19 vaccine for another reason, among respondents who answered “No, probably not” or “No, definitely not” when asked if they would get vaccinated if offered (item V3) and provided at least one reason for why they believe a COVID-19 vaccine is unnecessary.
Earliest date available: 2021-02-08
V6 and V5bc