1 Overview

The table below shows an overview of the study measures and timings of when they were measured:

2 Primary outcome measure

2.1 Vaccination status

Measured at wave 2 (January 2021) and wave 3 (March 2021)

  • Q. Have you received the COVID-19 vaccine?
January vaccine status n percent
0 Doses 765 82.3%
1 Dose 160 17.2%
2 Doses 5 0.5%
January vaccine status (Dummy coded) n percent
Not vaxed 765 82.3%
vaxed 165 17.7%
March vaccine status n percent
0 Doses 310 33.3%
1 Dose 206 22.2%
2 Doses 414 44.5%
March vaccine status (Dummy coded) n percent
Not vaxed 310 33.3%
vaxed 620 66.7%

3 Early vaccine eligibility factors

3.1 Age

Measured at wave 1 (Dec 2020)

  • Q. What is your age?

Response options:

  • 18 to 24
  • 25 to 34
  • 35 to 44
  • 45 to 54
  • 55 to 64
  • 65 to 74
  • 75 to 84
  • 85 or older

Summary statistics for the original age options are shown below (Median of 6 corresponds to 65-74).

vars n mean sd median trimmed mad min max range skew kurtosis se
Age 1 928 5.720905 1.283332 6 5.920699 0 1 8 7 -1.485948 2.430853 0.0421274

This table shows number and percent of respondents for each age bracket overall and by Veteran status.

Age Overall Veteran non-Veteran
2 0.2% 2 0.3% 0 0.0%
18 to 24 10 1.1% 0 0.0% 10 2.9%
25 to 34 27 2.9% 0 0.0% 27 7.8%
35 to 44 39 4.2% 7 1.2% 32 9.2%
45 to 54 48 5.2% 9 1.5% 39 11.3%
55 to 64 116 12.5% 62 10.6% 54 15.6%
65 to 74 475 51.1% 328 56.2% 147 42.5%
75 to 84 198 21.3% 162 27.7% 36 10.4%
85 or older 15 1.6% 14 2.4% 1 0.3%
Total 930 100.0% 584 100.0% 346 100.0%

Summary statistics for the age options collapsed for analysis are shown below (Median of 3 corresponds to 55-74).

vars n mean sd median trimmed mad min max range skew kurtosis se
Age: recoded 1 928 3.056034 0.6929186 3 3.119624 0 1 4 3 -0.7934924 1.386972 0.0227462
Age: recoded Overall Veteran non-Veteran
2 0.2% 2 0.3% 0 0.0%
18 to 34 37 4.0% 0 0.0% 37 10.7%
35 to 54 87 9.4% 16 2.7% 71 20.5%
55 to 74 591 63.5% 390 66.8% 201 58.1%
75 or older 213 22.9% 176 30.1% 37 10.7%
Total 930 100.0% 584 100.0% 346 100.0%

3.2 Proportion of state with +1 dose

The proportions of people who had received at least 1 dose of a COVID-19 vaccine in each state was retrieved from publicly available data: https://www.kff.org/coronavirus-covid-19/issue-brief/state-covid-19-data-and-policy-actions/

Summary statistics of the proportions of the state vaccinated for January and March 2021 are shown below.

vars n mean sd median trimmed mad min max range skew kurtosis se
January 1 926 3.773974 1.925146 3.50 3.457952 1.18608 0.1 9.2 9.1 1.6174096 2.824394 0.0632642
March 2 926 18.294708 1.906417 18.05 18.202965 1.11195 13.5 25.2 11.7 0.7453306 2.569440 0.0626488

Vaccination coverage rates and rankings in January and March 2021 shown in the table below.

  State % of state vaccinated in January % of state vaccinated in March Number of respondents % of respondents
1 NA NA 2 0.2%
2 Alabama 0.4 14.6 10 1.1%
3 Arizona 3 19.9 29 3.1%
4 Arkansas 0.1 16.3 5 0.5%
5 California 9.2 18.6 76 8.2%
6 Colorado 4.1 18.2 20 2.2%
7 Connecticut 5 24.9 13 1.4%
8 Delaware 1.4 18.1 4 0.4%
9 District of Columbia 9.1 20.9 2 0.2%
10 Florida 4.5 17.6 88 9.5%
11 Georgia 0.9 13.5 20 2.2%
12 Hawaii 0.6 19.7 9 1.0%
13 Idaho 2.7 16.6 7 0.8%
14 Illinois 2.3 18.8 38 4.1%
15 Indiana 3.6 17.1 16 1.7%
16 Iowa 3.7 20.4 10 1.1%
17 Kansas 2.9 16.9 3 0.3%
18 Kentucky 1.4 18.9 8 0.9%
19 Louisiana 4.2 17.6 7 0.8%
20 Maine 4.2 21.1 1 0.1%
21 Maryland 3.6 17.8 12 1.3%
22 Massachusetts 2.5 21.8 29 3.1%
23 Michigan 3.6 17.6 18 1.9%
24 Minnesota 2.9 20.2 21 2.3%
25 Mississippi 3.5 17 6 0.6%
26 Missouri 2.4 17.2 16 1.7%
27 Montana 3.6 20.4 5 0.5%
28 Nebraska 4 19.2 4 0.4%
29 Nevada 2.2 17.7 18 1.9%
30 New Hampshire 4.2 20 3 0.3%
31 New Jersey 3.5 19.2 22 2.4%
32 New Mexico 7 25.2 7 0.8%
33 New York 3.9 19.3 52 5.6%
34 North Carolina 2.7 17.7 38 4.1%
35 North Dakota 6 23.4 3 0.3%
36 Ohio 3.9 17.6 35 3.8%
37 Oklahoma 3.6 20.9 6 0.6%
38 Oregon 4.1 18 10 1.1%
39 Pennsylvania 2.7 17.9 41 4.4%
40 Puerto Rico NA NA 2 0.2%
41 Rhode Island 3.4 22 5 0.5%
42 South Carolina 2.1 16.8 24 2.6%
43 South Dakota 4.3 24 2 0.2%
44 Tennessee 4.2 15.7 15 1.6%
45 Texas 3.5 15.8 73 7.8%
47 Utah 4.4 17.4 1 0.1%
48 Vermont 4.5 20.8 4 0.4%
49 Virginia 3.3 18.5 35 3.8%
50 Washington 3.3 18.5 30 3.2%
51 West Virginia 6 20.6 3 0.3%
46 Total NA NA NA 100.0%

3.3 Veteran status

Measured at wave 1 (Dec 2020)

  • Q. Are you a U.S. military Veteran?

Response options: No [non-Veteran] (0), Yes [Veteran] (1)

Veteran status n percent
Non-Veteran 346 37.2%
Veteran 584 62.8%

3.4 Total number of comorbidities

Measured at wave 1 (Dec 2020)

Q. As far as you know, do you have any of the following health conditions at the present time?

  • Asthma, emphysema, or chronic bronchitis, COPD (other lung disease)
  • Arthritis or rheumatism
  • Cancer, diagnosed in the past 3 years
  • Diabetes
  • Digestive problems (such as ulcer, colitis, or gallbladder disease)
  • Heart trouble (such as angina, congestive heart failure, or coronary artery disease, having a past heart attack)
  • HIV illness or AIDS
  • Kidney disease
  • Liver problems (such as cirrhosis)
  • Stroke
  • High blood pressure (hypertension)
  • Very overweight or obese

Response options: No, do not have this condition (0), Yes, I have this condition (1).

Citation: Charlson ME, Pompei P, Ales KL, MacKenzie CR. A new method of classifying prognostic comorbidity in longitudinal studies: Development and validation. J Chronic Dis. 1987;40(5):373-383. doi:10.1016/0021-9681(87)90171-8.

Reported number of comorbidites was summed for each respondent to create a total score. Summary statistics for the total reported number of comorbidities are shown below.

vars n mean sd median trimmed mad min max range skew kurtosis se
Total number of comorbidities 1 930 1.474193 1.3748 1 1.310484 1.4826 0 7 7 0.8309065 0.1605565 0.0450815

The figure below shows the distribution of respondents reported number of comorbidities.

4 Demographic factors

4.1 Health literacy

Measured at wave 1 (Dec 2020)

  • Q1. How often do you have someone (like a family member, friend, hospital/clinic worker or caregiver) help you read instructions, pamphlets or other written health materials from your doctor or pharmacy?

Response scale: Never(1), Rarely(2), Sometimes(3), Often(4), Always(5).

Citation: Morris NS, MacLean CD, Chew LD, Littenberg B. The Single Item Literacy Screener: Evaluation of a brief instrument to identify limited reading ability. BMC Fam Pract. 2006;7(1):21. doi:10.1186/1471-2296-7-21.

Summary statistics for respondents health literacy are shown below.

vars n mean sd median trimmed mad min max range skew kurtosis se
Health Literacy 1 930 1.23871 0.6811363 1 1.052419 0 1 5 4 3.357355 11.8841 0.0223353

The figure below shows the distribution of respondents responses to the health literacy item.

4.2 Numeracy

Measured at wave 1 (Dec 2020)

  • Q1. How good are you at working with fractions?
  • Q2. How good are you at figuring out how much a shirt will cost if it is 25% off?

Response scale (slider): Not at all good(1), — (2), — (3), — (4), — (5) Extremely good (6).

  • Q3. How often do you find numerical information to be useful?

Response scale (slider): Never(1), — (2), — (3), — (4), — (5) Very often (6).

Citation: McNaughton CD, Cavanaugh KL, Kripalani S, Rothman RL, Wallston KA. Validation of a Short, 3-Item Version of the Subjective Numeracy Scale. Med Decis Mak Int J Soc Med Decis Mak. 2015;35(8):932-936. doi:10.1177/0272989X15581800.

Citation: Fagerlin A, Zikmund-Fisher BJ, Ubel PA, Jankovic A, Derry HA, Smith DM. Measuring numeracy without a math test: development of the Subjective Numeracy Scale. Med Decis Making. 2007;27(5):672-680. doi:10.1177/0272989X07304449

The reliability of the numeracy items was good (shown below), with Cronbach’s Alpha=.87. Items were then averaged to create a numeracy scale.

raw_alpha std.alpha G6(smc) average_r S/N ase mean sd median_r
0.8682973 0.8752099 0.8245073 0.7004031 7.013454 0.0072291 4.978853 1.133651 0.6960336

Summary statistics for the numeracy scale are shown below.

vars n mean sd median trimmed mad min max range skew kurtosis se
Numeracy 1 930 4.978853 1.133651 5.333333 5.160394 0.9884 1 6 5 -1.221692 1.034928 0.0371739

The figures below show the distribution of respondents responses to the individual numeracy items.

4.3 Race/Ethnicity

Measured at wave 1 (Dec 2020)

  • Q1. Are you Hispanic or Latino/a or Latinx?

Response options: No [non-Hispanic] (0), Yes [Hispanic] (1).

Overall Veteran non-Veteran
Non-Hispanic 837 90.0% 522 89.4% 315 91.0%
Hispanic 92 9.9% 61 10.4% 31 9.0%
No response 1 0.1% 1 0.2% 0 0.0%
Total 930 100.0% 584 100.0% 346 100.0%
  • Q2. What is your race? Mark all that apply.

Response options:

  • American Indian or Alaskan Native
  • Asian or Asian American
  • Black or African American
  • Native Hawaiian or other Pacific Islander
  • White or European American
  • Other (please specify)

The table below shows the number and percent of respondents answers to the race and ethnicity questions together.

Hispanic Race n (%)
Non-Hispanic American Indian or Alaskan Native 4 (0.5%)
Non-Hispanic Asian or Asian American 26 (3.1%)
Non-Hispanic Black or African American 64 (7.6%)
Non-Hispanic Multiple 8 (1.0%)
Non-Hispanic Native Hawaiian or other Pacific Islander 2 (0.2%)
Non-Hispanic Other 13 (1.6%)
Non-Hispanic White or European American 720 (86.0%)
No response White or European American 1 (100.0%)
Hispanic Asian or Asian American 1 (1.1%)
Hispanic Black or African American 5 (5.4%)
Hispanic Multiple 2 (2.2%)
Hispanic Other 4 (4.3%)
Hispanic White or European American 80 (87.0%)

The below table shows respondents Race/Ethnicity as coded for analysis.

Race/Ethnicity n percent
No 210 22.6%
Yes 720 77.4%

5 Psychological factors

5.1 Worry about getting COVID-19

Measured at wave 1 (Dec 2020)

  • Q1. How worried are you about getting COVID-19?

Response scale: Not at all worried (1), (2), (3), (4), Very worried (5).

Summary statistics for the worry about getting COVID-19 item are shown below.

vars n mean sd median trimmed mad min max range skew kurtosis se
Worry about COVID-19 1 930 2.91828 1.287427 3 2.897849 1.4826 1 5 4 0.1945095 -1.045154 0.0422164

The figure below shows the distribution of respondents responses to the worry about getting COVID-19 item.

5.2 COVID-19 risk perception

Measured at wave 1 (Dec 2020)

  • Q1. In your opinion, how likely is it that you will get COVID-19 during the next month?
  • Q2. If you were to get COVID-19, how likely do you think it is that you would need to be hospitalized?
  • Q3. If you were to get COVID-19, how likely do you think it is that you would die?

Response scale: Not at all likely (1), — (2), — (3), — (4), Very likely (5).

The reliability of the COVID-19 risk perception items is good (shown below), with Cronbach’s Alpha=.79. Items were then averaged to create a COVID-19 risk perception scale.

raw_alpha std.alpha G6(smc) average_r S/N ase mean sd median_r
0.7919148 0.785356 0.7619468 0.5494735 3.658876 0.0113639 2.460172 0.9312925 0.4467082

Summary statistics for the COVID-19 risk perceptions scale are shown below.

vars n mean sd median trimmed mad min max range skew kurtosis se
X1 1 929 2.460172 0.9312925 2.333333 2.428859 0.9884 1 5 4 0.3064475 -0.5219726 0.0305547

The figures below show the distribution of respondents responses to the individual COVID-19 risk perception items.

5.3 Emory Vaccine Confidence Index

Measured at wave 2 (Jan 2021)

Please rate your level of trust in each of the following items:

  • Scientists involved in developing and testing new vaccines
  • Federal government agencies responsible for monitoring the safety of recommended vaccines
  • Centers for Disease Control and Prevention (CDC), the federal government agency that makes recommendations about who should get licensed vaccines
  • Food & Drug Administration (FDA), the federal government agency that licenses vaccines

Response scale: Not trust(1), Little trust (2), Moderate trust (3), Complete trust (4), Don’t know (5).

Please indicate your level of confidence in each item below

  • Vaccines recommended for children are safe.
  • My doctor/nurse is a reliable source of trustworthy vaccine information
  • My doctor/nurse has my best health interests mind when making vaccine recommendations

Response scale (slider): Not at all confident (1), Somewhat confident (2), Confident (3), Mostly confident (4), Very confident (5) Don’t know (6).

Indicate your agreement or disagreement with the following statements: It is important for everyone to get the recommended vaccines for their child(ren)

Response scale (slider): Strongly disagree (1), Disagree (2), Neutral (3), Agree (4), Strongly agree (5).

Citation: Frew PM, Murden R, Mehta CC, et al. Development of a US trust measure to assess and monitor parental confidence in the vaccine system. Vaccine. 2019;37(2):325-332. doi:10.1016/j.vaccine.2018.09.043.

The reliability of the Emory vaccine confidence index items is good (shown below), with Cronbach’s Alpha=.88. Items were then averaged to create an Emory vaccine confidence scale.

raw_alpha std.alpha G6(smc) average_r S/N ase mean sd median_r
0.8795199 0.8825262 0.9025959 0.4842882 7.512539 0.0060935 2.255095 0.5894596 0.4490731

Summary statistics for the Emory vaccine confidence scale are shown below.

vars n mean sd median trimmed mad min max range skew kurtosis se
Emory vaccine confidence 1 930 17.97527 4.811901 19 18.60887 4.4478 0 24 24 -1.402225 2.426993 0.1577885

The figures below show the distribution of respondents responses to the Emory vaccine confidence items.

5.4 Flu vaccine important

Measured at wave 2 (Jan 2021)

  • Q1. It is important for everyone to get the flu vaccine.

Response scale (slider): Strongly disagree (1), Disagree (2), Neutral (3), Agree (4), Strongly agree (5).

Summary statistics for respondents opinions on importance of flu vaccines are shown below.

vars n mean sd median trimmed mad min max range skew kurtosis se
Flu vaccine important 1 930 4.191398 1.068147 5 4.388441 0 1 5 4 -1.354466 1.208646 0.0350259

The figure below shows the distribution of respondents responses to the flu vaccine important item.

5.5 COVID-19 vaccine important

Measured at wave 2 (Jan 2021)

  • Q1. It is important for all adults to get the COVID-19 vaccine.

Response scale (slider): Strongly disagree (1), Disagree (2), Neutral (3), Agree (4), Strongly agree (5).

Summary statistics for respondents opinions of the importance of COVID-19 vaccines are shown below.

vars n mean sd median trimmed mad min max range skew kurtosis se
COVID-19 vaccine important 1 930 4.332258 1.02095 5 4.543011 0 1 5 4 -1.685713 2.351776 0.0334783

The figure below shows the distribution of respondents responses to the COVID-19 vaccine important item.

5.6 COVID-19 Vaccine intentions

Measured at wave 1 (Dec 2020)

  • Q1. A coronavirus vaccine will soon become available. How interested are you in getting the vaccine?

Response scale: I definitely do NOT want to get the vaccine (1), I do NOT want to get the vaccine (2), Uncertain (3), I WANT to get the vaccine (4), I definitely WANT to get the vaccine (5).

Summary statistics for respondents COVID-19 vaccine intentions are shown below.

vars n mean sd median trimmed mad min max range skew kurtosis se
COVID-19 vaccine intentions 1 930 4.122581 1.200119 5 4.358871 0 1 5 4 -1.255202 0.5955115 0.0393535

The figure below shows the distribution of respondents responses to the COVID-19 vaccine intention item.

5.7 Trust in Healthcare

Measured at wave 1 (Dec 2020)

Please indicate how much you agree or disagree with each statement. There are no right or wrong answers. Please answer in a way that reflects your own personal beliefs:

  • The Health Care System does its best to make patients health better
  • The Health Care System covers up its mistakes
  • Patients receive high quality medical care from the Health Care System
  • The Health Care System makes too many mistakes
  • The Health Care System puts making money above patients’ needs
  • The Health Care System gives excellent medical care
  • Patients get the same medical treatment from the Health Care System no matter what the patient’s race or ethnicity
  • The Health Care System lies to make money
  • The Health Care System experiments on patients without them knowing

Response scale: Strongly disagree (1), Disagree (2), Somewhat disagree (3), Neither agree nor disagree (4), Somewhat agree (5), Agree (6), Strongly agree (7).

Citation: Shea JA, Micco E, Dean LT, McMurphy S, Schwartz JS, Armstrong K. Development of a Revised Health Care System Distrust Scale. J Gen Intern Med. 2008;23(6):727-732. doi:10.1007/s11606-008-0575-3.

The reliability of the Healthcare trust items was good (shown below), with Cronbach’s Alpha=.89. Items were then averaged to create a Healthcare trust scale.

raw_alpha std.alpha G6(smc) average_r S/N ase mean sd median_r
0.8885886 0.8932149 0.9101051 0.4817042 8.364602 0.0054844 4.32957 1.071551 0.449045

Summary statistics for the healthcare trust scale are shown below.

vars n mean sd median trimmed mad min max range skew kurtosis se
Healthcare Trust 1 930 4.32957 1.071551 4.222222 4.315113 1.153133 0.7777778 6.444444 5.666667 0.0073459 -0.3368769 0.0351376

The figures below show the distribution of respondents responses to the individual healthcare trust items (Response scale: Strongly disagree (1), Disagree (2), Somewhat disagree (3), Neither agree nor disagree (4), Somewhat agree (5), Agree (6), Strongly agree (7)).

5.8 (Lack of) Belief in science

Measured at wave 1 (Dec 2020)

Please indicate how much you agree or disagree with each statement. There are no right or wrong answers. Please answer in a way that reflects your own personal beliefs:

  • People trust scientists a lot more than they should
  • People don’t realize just how flawed a lot of scientific research really is
  • A lot of scientific theories are dead wrong
  • Sometimes I think we put too much faith in science
  • Our society places too much emphasis on science
  • I am concerned by the amount of influence that scientists have in society

Response scale (slider): Strongly disagree (1), Disagree (2), Somewhat disagree (3), Neither agree nor disagree (4), Somewhat agree (5), Agree (6), Strongly agree (7).

Citation: Hartman RO, Dieckmann NF, Sprenger AM, Stastny BJ, DeMarree KG. Modeling attitudes toward science: development and validation of the credibility of science scale. Basic Appl Soc Psychol. 2017;39(6):358-371. doi:10.1080/01973533.2017.1372284

The reliability of the (lack of) Belief in science items was good (shown below), with Cronbach’s Alpha=.96. Items were then averaged to create a (lack of) Belief in science scale.

raw_alpha std.alpha G6(smc) average_r S/N ase mean sd median_r
0.9584184 0.9583375 0.9533686 0.7931205 23.00238 0.0021166 3.265054 1.562983 0.7878162

Summary statistics for the (lack of) Belief in science scale are shown below.

vars n mean sd median trimmed mad min max range skew kurtosis se
Lack of belief in science 1 930 3.265054 1.562983 3.333333 3.1931 1.7297 1 7 6 0.2643233 -0.76854 0.0512522

The figures below show the distribution of respondents responses to the individual belief in science items (Response scale: Strongly disagree (1), Disagree (2), Somewhat disagree (3), Neither agree nor disagree (4), Somewhat agree (5), Agree (6), Strongly agree (7)).

5.9 Belief in conspiracy theories

Measured at wave 3 (March 2021)

Below are things that some people might believe. Please indicate whether you personally think each statement is true or false.

  • The virus causing COVID-19 was purposefully released by a government or person.
  • COVID-19 is actually a biological weapon being tested.
  • The current COVID-19 outbreak is actually a form of population control to reduce the number of people in the infected countries.
  • The COVID- 19 vaccine is a microchip so the government can track you.

Response scale: Definitely false (1), Probably false (2), Unsure (3), Probably true (4),Definitely true (5)

The reliability of the belief in conspiracy theories items was good (shown below), with Cronbach’s Alpha=.88. Items were then averaged to create a belief in conspiracy theories scale.

raw_alpha std.alpha G6(smc) average_r S/N ase mean sd median_r
0.8770891 0.8864585 0.8788258 0.6612281 7.807355 0.0061532 1.755108 0.9398848 0.6769861

Summary statistics for the belief in conspiracy theories scale are shown below.

vars n mean sd median trimmed mad min max range skew kurtosis se
belief in conspiracy theories 1 930 1.755108 0.9398848 1.25 1.603159 0.37065 1 5 4 1.118216 0.314083 0.03082

The figures below show the distribution of respondents responses to the individual belief in conspiracy theories items.

5.10 Conservative beliefs

Measured at wave 2 (Jan 2021)

  • Q1. Here is a 7-point scale on which the political views that people might hold are arranged from extremely liberal (left) to extremely conservative (right). Where would you place yourself on this scale?

Response scale: Extremely liberal (1), Moderately liberal (2), Slightly liberal (3), Neutral (4), Slightly conservative (5), Moderately conservative (6), Extremely conservative (7).

Summary statistics for the conservative beliefs item are shown below.

vars n mean sd median trimmed mad min max range skew kurtosis se
Conservative beliefs 1 928 4.440733 1.764672 5 4.50672 1.4826 1 7 6 -0.3379234 -0.9045239 0.0579282

The figure below shows the distribution of respondents responses to the conservative beliefs item.

5.11 Maximizing

Measured at wave 1 (Dec 2020)

  • Q1. Sometimes, medical action is clearly necessary, and sometimes it is clearly NOT necessary. Other times, people differ in their beliefs about whether medical action is needed. In medical situations where it’s not clear, do you tend to lean towards taking action or do you lean towards waiting and seeing if action is needed? Importantly, there is no “right” way to be. Please answer on the 1-6 scale below:?

Response scale: I lean toward waiting and seeing (1), — (2), — (3), — (4), — (5), I lean toward taking action (6).

Citation: Scherer LD, Zikmund-Fisher BJ. Eliciting medical maximizing-minimizing preferences with a single question: development and validation of the MM1. Med Decis Making. 2020;40(4):545-550. doi:10.1177/0272989X20927700

Summary statistics for respondents health maximizing are shown below.

vars n mean sd median trimmed mad min max range skew kurtosis se
Maximizing 1 930 3.894624 1.457571 4 3.954301 1.4826 1 6 5 -0.2836856 -0.8111278 0.0477956

The figure below shows the distribution of respondents responses to the maximizing item