# Questions and Coding

The symptom surveys have been deployed in several waves. We have tried to ensure the coding of waves is consistent. This page provides the full survey text and coding schemes.

1. Basic Coding Rules
2. Privacy Restrictions
3. Wave 1
4. Wave 2
5. Wave 3
6. Wave 4
1. Summary of Changes
7. Wave 5
1. Summary of Changes
8. Wave 6
1. Summary of Changes
9. Wave 7
1. Summary of Changes
10. Wave 8
1. Summary of Changes
11. Wave 9
12. Wave 10
1. Summary of Changes

## Basic Coding Rules

All choice responses are recorded numerically starting from 1, in displayed order from left to right and top to bottom. When the respondent is allowed to select multiple responses, these are shown separated by commas, such as 2,4,6. Questions left blank or with invalid responses are recorded in the CSV files as NA.

Timestamps are provided in Pacific time (UTC-7). The following metadata columns describe each survey response:

• StartDatetime: The time the respondent began the survey.
• EndDatetime: The time of the last activity by the respondent on the survey. If they submitted the survey, this is the time it was submitted. If the user did not complete the survey, their response may have been recorded automatically after a timeout; this is the time of their last activity, not of the recording. See the response files documentation for details on the automatic recording of responses.
• weight: The survey weight calculated by Facebook, for demographically adjusting estimates. See the weights documentation for details on how to use these weights.

The following columns were added beginning when Wave 4 was deployed:

• wave: Integer specifying the survey wave this respondent completed; see below for the full list.
• UserLanguage: Language the respondent completed the survey in.
• fips: The primary county FIPS code corresponding to the ZIP code selected by the respondent. Note that ZIP codes can cross county and even state boundaries; if a respondent’s ZIP is in multiple counties, the FIPS reported in this column corresponds to the county the ZIP overlaps most with. If a ZIP is not more than 50% in any one county, or if their reported ZIP code cannot be found, NA is reported.

Coding details for each survey wave follow.

## Privacy Restrictions

To prevent respondents from being identifiable in the response data, responses with ZIP codes with populations of 100 or fewer have their location set to NA. This affects item A3 in the individual response files. (This change was implemented with the introduction of Wave 4. Previously, all ZIPs were reported.)

Invalid ZIP codes are preserved unchanged, and these rows are reported in the individual response files with their invalid ZIPs.

Additionally, beginning in wave 4, items D6 and D7 ask respondents for race and ethnicity. These columns are not available in the microdata files due to reidentification concerns. However, contingency tables that aggregate by race and other demographic variables are available.

## Wave 1

Wave 1 was first deployed on April 6, 2020. This was replaced by Wave 2, but some responses still arrive from respondents who received a link before Wave 2 was deployed.

Warning: Item A2 shows high missingness and strange values in Wave 1, possibly due to incorrect validation in the Qualtrics survey. Item A2 should not be used in Wave 1 data until this problem is understood.

## Wave 2

Wave 2 was first deployed on April 15, 2020. This was replaced by Wave 3, but some responses still arrive from respondents who received a link before Wave 3 was deployed.

### Summary of Changes

• Item A1 changed from

In the past 24 hours, have you or anyone in your household had any of the following:

to

In the past 24 hours, have you or anyone in your household experienced any of the following:

• Item A2 changed to specify “fever, along with at least one other symptom in the above list” rather than simply “at least one symptom.”
• Item A3 changed from

What is the ZIP Code of the city or town where you slept last night? [We mean the place where you are currently staying. This may be different from your usual residence.]

to

What is your current ZIP code?

## Wave 3

Wave 3 was first deployed on May 21, 2020. It is available in English, as well as

• Simplified Chinese
• English (UK)
• Spanish (Latin America)
• Spanish
• French
• Brazilian Portuguese
• Vietnamese

Files:

### Summary of Changes

• Now available in languages besides English, listed above. The language shown to the user defaults to the language they prefer on Facebook, if available, but a drop-down allows the user to select other languages.
• Consent text now mentions receiving “your language preference” from Facebook, to allow Qualtrics to select the appropriate translation automatically.
• Consent question now requires the respondent be located in the U.S.
• Item B2 now includes eye pain as a symptom.
• Item C5 moved to be asked before item C4.

## Wave 4

Wave 4 was first deployed September 8, 2020. It is available in English, as well as

• Simplified Chinese
• English (UK)
• Spanish (Latin America)
• Spanish
• French
• Brazilian Portuguese
• Vietnamese

Files:

### Summary of Changes

Wave 4 is a major change to the survey instrument. Some items have been removed and several new items have been added. Please review the changes carefully when you use responses from both waves.

The survey consent text has been altered to more clearly indicate that

Even if you are healthy, your responses may contribute to a better public health understanding of the spread of the coronavirus pandemic and its effects on public health and well-being. This may help improve our local and national responses to the pandemic and our understanding of how it has affected society.

This is broader than the prior text, which suggested the survey was only to understand “where the coronavirus pandemic is moving”, and ensures we obtain consent for the full range of uses for the survey.

#### New Items

• Following item B2, item B2c now asks which reported symptoms are “new or unusual” for the respondent. This is intended to distinguish symptoms of chronic conditions (such as allergies) from symptoms that may be COVID-related (or due to influenza or another condition).
• Item B7 now asks whether the respondent has sought medical care, such as visiting a doctor or urgent care clinic. This will allow researchers to understand how people seek medical care, and what fraction of people do so at any given time.
• Items B8, B10, B10a, B10b, B11, B12, and B12a more comprehensively ask about testing, including whether the respondent has tried to be tested but could not get a test, and why they were tested.
• Item C13 asks about specific activities, such as working or going to a restaurant, that the respondent may have done in the past 24 hours. Item C13a asks whether the respondent wore a mask while doing them.
• Item C14 asks “In the past 5 days, how often did you wear a mask when in public?”
• Item D6 now asks if the respondent is of Hispanic, Latino, or Spanish origin. Note that this item may not be available in individual response files until procedures to prevent reidentification of respondents are finalized.
• Item D7 now asks the respondent’s race. Note that this item may not be available in individual response files until procedures to prevent reidentification of respondents are finalized.
• Item D8 asks for the highest level of school the respondent has completed.
• Item D9 asks if the respondent has worked for pay in the past 4 weeks, while items Q64 - Q80 ask the respondent to identify their occupation in a form based on the Standard Occupational Classification System. (Each respondent will only see two of these items; the first requests a broad category, the second a more detailed classification.)
• Item D10 asks if any of the respondent’s work for pay in the past 4 weeks was outside their home.

#### Changed Items

• Item B2 now includes eye pain and chills as symptoms.
• Item B2b now asks how long the respondent has had one unusual symptom, if they report having one in item B2c. It no longer asks how long the respondent has had any reported symptom.
• Item C1 now separates type 1 and type 2 diabetes, coded separately. The coding for both is different from the original coding for “diabetes”, so they can be analyzed separately.
• Item C8 now asks how often the respondent has “felt isolated from others”, along with the existing items about anxiety and depression.

#### Removed Items

• Item A2b (“How many people are there in your household in total (including yourself)?”) has been removed, as have items D3, D4, and D5. They have been replaced with item A5, which asks for the people in the household broken down by age, including the respondent.
• Items B3 and Q40, asking the temperature of respondents with fevers, have been removed.
• Item B4, asking if the respondent’s cough involved mucus, has been removed.
• Item B5 (“Have you been tested for COVID-19 (coronavirus) for your current illness?”) has been removed. It has been replaced with items B8-B12, described above.
• Item B6 is now subsumed by item B7.
• Item C2 (“Have you had a flu shot in the last 12 months?”) was not being used by research partners and has been removed.
• Item C3 (“In the past 5 days, have you gone to work outside of your home?”) has been replaced by a combination of items C13 and D9.
• Item C4 is replaced by items Q64, Q68, and Q69.
• Item C5 is replaced by items Q64, Q68, and Q69.
• Item C7 (“To what extent are you intentionally avoiding contact with other people?”) is removed, replaced by the more specific items C13, C13a, and C14.
• Item Q36 (“How much of a threat would you say the coronavirus outbreak is to your household’s finances?”) has been removed and replaced with item C15, for consistency with the international version of the survey.
• Item D1b (“Are you currently pregnant?”) has been removed.

## Wave 5

Wave 5 was deployed on November 24, 2020. Deployment was phased: a fraction of users were invited to take Wave 4, while the majority were invited to Wave 5, so data users can determine if changes in responses are due to survey revisions or to population changes at the same time. Wave 5 is available in English, as well as

• Simplified Chinese
• English (UK)
• Spanish (Latin America)
• Spanish
• French
• Brazilian Portuguese
• Vietnamese

Files:

### Summary of Changes

Wave 5 contains minor changes to the survey instrument and a few new items. Please review the changes carefully when you use responses from multiple waves of this survey.

The survey consent text has been altered to encourage respondents to answer the survey, even if they have already taken it before:

We encourage you to complete the survey each time you are invited, even if you have participated before. Completing the survey again will help us understand how the situation is changing.

Wave 5 now clearly states that the data may be shared and aggregates publicly when released:

The de-identified results of this survey may be used for our future studies or shared with other investigators for their research studies. Results published by us and other researchers will be in aggregate and will not identify individual participants or their responses.

#### New Items

• Item C16 asks respondents to estimate how many people are wearing masks in their community.
• Item C7 was previously asked in Waves 1-3; it asks respondents the extent they are avoiding other people.
• Item C17 asks whether respondents have received a flu vaccine. The time frame and responses are adapted to specify the current seasonal flu vaccine. A more general version inquiry about the flu vaccine appeared in Wave 1-3 as item C2.
• Items E1-E3 ask about household children and their education during the pandemic. These items appear for respondents who indicate there is a child in their household under the age of 18. E1 asks respondents to indicate the current grade level(s) the child(ren) in their household. Item E2 asks the respondents if the child(ren) are attending in-person classes part time or full time. Item E3 asks respondents what measures are applied to prevent the spread of COVID-19 when the child(ren) attend in-person classes (e.g. mandatory, mask wearing, closed communal areas).
• Note: Soon after survey deployment, we discovered that the translations for French, Brazilian Portuguese, and Spanish (not Latin America) translated these questions to use terms appropriate for education systems in those countries, rather than education in the US. We disabled the question in these translations, and are preparing updated translations that use the correct terms.

#### Changed Items

• Item B2 now includes headaches and changes in sleep as symptoms.
• Item D8 now includes the option of Master’s degree (unfortunately omitted in Wave 4) and has examples of professional degree for clarification.

#### Removed Items

• There are no items from Wave 4 that were removed in the Wave 5 version of this survey.

## Wave 6

Wave 6 was deployed on December 19, 2020. It is available in English, as well as

• Simplified Chinese
• English (UK)
• Spanish (Latin America)
• Spanish
• French
• Brazilian Portuguese
• Vietnamese

Files:

### Summary of Changes

Wave 6 is a minor change to the survey instrument with the addition of a few new items regarding COVID-19 vaccine intent. We intend to expand the scope of our questions in the next wave after the beginning of the year. Please review the changes carefully when you use responses from multiple waves of this survey.

#### New Items

• Item V3 asks respondents how likely they would choose to be vaccinated, if they were offered a COVID vaccine.
• Item V4 asks respondents if their intent to get a vaccination would change based on recommendations from different sources (e.g. friends and family, health workers, organizations). Note: Between December 19 and December 23, 2020, non-English translations of this question labeled the answer choices inconsistently with the English version. We corrected this on December 23, and reissued the affected microdata files to delete responses to V4 by respondents seeing an affected translation. The corrected question is labeled V4a in the Qualtrics survey, but appears in the microdata files as V4. Because we reissued the affected data, you should not need to make any changes to your analysis.
• Note: Items V1 and V2 are shown in the Qualtrics files. These ask the respondent if they have received a COVID vaccination. However, due to reidentification concerns, these items were disabled in the display logic, and were not displayed to or asked of respondents. On January 6, 2021, item V1 was enabled, and V3 and V4 were made conditional on respondents not answering “yes” to V1. Item V2 remains disabled in the display logic.

## Wave 7

Wave 7 was deployed on January 12, 2021. It is available in English, as well as

• Simplified Chinese
• English (UK)
• Spanish (Latin America)
• Spanish
• French
• Brazilian Portuguese
• Vietnamese

Files:

### Summary of Changes

Wave 7 includes minor modifications to the existing questions regarding COVID -19 vaccination. We intend to expand the scope of our questions in the next wave at the end of January 2021. Please review the changes carefully when you use responses from multiple waves of this survey.

#### Changed Items

• Slight changes to the wording of questions V1, V2, V3, and V4.
• Item V2 was included in Wave 6 but not shown to respondents. We have enabled item V2 for Wave 7.

#### New Items

• Item V9 asks if respondents are concerned about a side effect from the COVID-19 vaccination. We ask it of all respondents, regardless of whether they have already received a vaccination.

#### Notes

• This wave configures numeric answer items to require answers to be ≥0. We did this via JavaScript by setting the min = "0" attribute on the input box. While this should prevent respondents from accidentally entering negative numbers, those who deliberately want to enter negative numbers can bypass the restriction.

## Wave 8

Wave 8 was deployed on February 8, 2021. It is available in English, as well as

• Simplified Chinese
• English (UK)
• Spanish (Latin America)
• Spanish
• French
• Brazilian Portuguese
• Vietnamese

Files:

### Summary of Changes

Wave 8 expands the scope of the survey items about COVID-19 vaccinations. These new items were meant to capture reasons for vaccine hesitancy among respondents.

#### Changed Items

• Answer options for items C1, on chronic medical conditions, have been revised and expanded.
• Answer options for the occupation questions, including Q64, Q68, Q69, and Q71, were revised and expanded for clarity. Please review the changes carefully when you use responses from multiple waves of this survey, since they may shift which occupations respondents choose.
• C14a is a revision of item C14, changed from “the past 5 days” to “the past 7 days” to be consistent with other items on the COVID Symptom Survey. C14a replaces C14.
• C17a is a revision of item C17, which asked respondents if they have had a flu vaccination since June 2020. C17a changed the date to July 1, 2020 and simplified the wording.
• In item V4, the “local health workers” category was changed to read “Doctors and other health professionals you go to for medical care”.

#### New Items

• Item V2a ask respondents that have received a COVID-19 vaccine and indicated that they have not had 2 doses of the vaccine whether they intend to get the required doses.
• Items V5a-V5d and V6 were added to capture reasons for respondents not wanting to get a COVID-19 vaccine. The questions are displayed based on the respondents’ answers to V2a and V3.
• Item D1b was previously removed in wave 4 and asks respondents that identify as not male if they are currently pregnant.
• Item D11 ask respondents if they smoke cigarettes.

## Wave 9

Wave 9 was skipped to synchronize our numbering with the international survey administered by the University of Maryland.

## Wave 10

Wave 10 was deployed on March 2, 2021. For the following 7 days, 15% of respondents (selected at random) continued to receive Wave 8, allowing for comparisons of responses between the two waves. Wave 10 is available in English, as well as

• Simplified Chinese
• English (UK)
• Spanish (Latin America)
• Spanish
• French
• Brazilian Portuguese
• Vietnamese

Files:

### Summary of Changes

Wave 10 further expands the scope of survey items about COVID-19 vaccination. These new items were meant to capture reasons for vaccine hesistancy among respondents and gauge access. Other items were revised or replaced. Please review the changes carefully when you use responses from multiple waves of this survey.

#### New Items

• Item V11 ask respondents if they have an appointment to receive a COVID-19 vaccine.
• Item V12 ask respondents if they have tried to get an appointment to receive a COVID-19 vaccine.
• Item V13 ask respondents how informed they feel about how they will be able to get a COVID-19 vaccine.
• Item V14 asks respondent when they think they will be able to get a COVID-19 vaccine.

#### Changed Items

• Item A1 now includes description of fever in Celsius as well as Fahrenheit.
• Item A5 was changed to say “from 18 to 64 years old” instead of “between 18 and 64 years old”.
• The instructions following the question text in items B2 and D7 was changed to be consistent with all other multiple response questions and reads “Please select all that apply.”
• Item B10a was changed to remind the respondent “You answered that you have been tested for coronavirus (COVID-19) in the past 14 days.”
• Items B10b, C13a, C13b, was changed to now state “in the past 14 days”, versus the previous version that stated “in last 14 days”.
• Item B10b response options were changed to provide more specificity. Blood donation was added to the option “I was tested while receiving other medical care, such as surgery” and a “None of the above” response option was added to be consistent with other questions.
• Item V2a was changed to say “recommended doses”; previous versions said “required doses” (V2).
• Items V5a-V5d question wording was changed to better match the question stem (V3). For example, if respondents selected for Item V3 (“If a vaccine to prevent COVID-19 were offered to you today, would you choose to get vaccinated?”) response option 2 (“Yes, probably”). The following question would be V5a (“Which of the following, is any, are reasons that you only probably would choose to get the COVID-19 vaccine?”).
• Item C13 was replaced with item C13b, which asks specifically whether the activities occurred indoors. Item C13a was similarly replaced with item C13c to reflect mask use during those indoor activities.
• Items C6 and C8 were changed to refer to the past 7 days, rather than the past 5 days, to be consistent with other items on the survey. They were renamed to C6a and C8a to reflect this change.
• Typos were fixed in Q67 and Q78.

#### Removed Items

• Item B2b (“For how many days have you had at least one new or unusual symptom?”) was removed.
• Item C11 (“In the past 24 hours, have you had direct contact with anyone who recently tested positive for COVID-19 (coronavirus)?”), and the follow-up question, item C12 (“Was this person a member of your household?”), were removed.
• Item A3b (“In which state are you currently staying?”) was removed. Respondents are asked their ZIP code in item A3, and while some ZIP codes cross state lines, we judged the duplication was not necessary.