# 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

## 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.

## 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.

Note that this changelog is a draft; as the survey instrument is finalized, this changelog will be updated to include all final changes.

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.